WO2005095936A1 - An integrated electronic sensor - Google Patents

An integrated electronic sensor Download PDF

Info

Publication number
WO2005095936A1
WO2005095936A1 PCT/IE2005/000033 IE2005000033W WO2005095936A1 WO 2005095936 A1 WO2005095936 A1 WO 2005095936A1 IE 2005000033 W IE2005000033 W IE 2005000033W WO 2005095936 A1 WO2005095936 A1 WO 2005095936A1
Authority
WO
WIPO (PCT)
Prior art keywords
sensor device
integrated sensor
interconnect
electrodes
integrated
Prior art date
Application number
PCT/IE2005/000033
Other languages
French (fr)
Inventor
Timothy Cummins
Original Assignee
Timothy Cummins
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Timothy Cummins filed Critical Timothy Cummins
Priority to EP05718823.7A priority Critical patent/EP1730506B1/en
Priority to JP2007505733A priority patent/JP2007535662A/en
Publication of WO2005095936A1 publication Critical patent/WO2005095936A1/en

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/02Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
    • G01N27/22Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/02Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
    • G01N27/22Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance
    • G01N27/223Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating capacitance for determining moisture content, e.g. humidity
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00Details of semiconductor or other solid state devices
    • H01L23/52Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames
    • H01L23/522Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body
    • H01L23/528Geometry or layout of the interconnection structure
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/02Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
    • H01L27/04Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body
    • H01L27/06Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including a plurality of individual components in a non-repetitive configuration
    • H01L27/0611Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including a plurality of individual components in a non-repetitive configuration integrated circuits having a two-dimensional layout of components without a common active region
    • H01L27/0617Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including a plurality of individual components in a non-repetitive configuration integrated circuits having a two-dimensional layout of components without a common active region comprising components of the field-effect type
    • H01L27/0629Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including a plurality of individual components in a non-repetitive configuration integrated circuits having a two-dimensional layout of components without a common active region comprising components of the field-effect type in combination with diodes, or resistors, or capacitors
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/02Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
    • G01N27/04Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
    • G01N27/12Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
    • G01N27/121Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid for determining moisture content, e.g. humidity, of the fluid
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/02Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
    • H01L27/04Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body
    • H01L27/10Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including a plurality of individual components in a repetitive configuration
    • H01L27/105Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including a plurality of individual components in a repetitive configuration including field-effect components
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/15Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components with at least one potential-jump barrier or surface barrier specially adapted for light emission
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/0001Technical content checked by a classifier
    • H01L2924/0002Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Definitions

  • the invention relates to electronic sensors.
  • US6724612 and US6690569 describe sensor devices having both electronic and sensing components, the latter being capacitive electrodes.
  • the electrodes require platinum or gold coating, and deposition of a polymer as a moisture-sensing dielectric. This processing is not amenable to high- volume semiconductor processing.
  • the invention addresses these issues.
  • an integrated sensor device comprising:
  • MOS circuits in a semiconductor substrate interconnect levels with interconnect conductors and insulating dielectric, said levels being over the substrate and interconnecting the MOS circuits, the interconnect levels incorporating a sensor having electrodes embedded in the interconnect dielectric, and the MOS circuits including a processor for processing signals from the sensor electrodes.
  • the senor comprises a porous oxide for ingress of a gas or humidity being sensed.
  • the porous oxide is carbon-doped SiO 2 .
  • the senor is a capactive sensor.
  • the senor comprises a passivation layer over the sensor electrodes.
  • the porous oxide is deposited on the passivation layer, and the MOS circuits detect changes in a fringe field between the electrodes.
  • the passivation layer is of the same composition as the etch stop material.
  • the passivation layer is of Si 3 N 4 composition.
  • the passivation layer is recessed over the sensing electrodes.
  • the porous oxide is between the electrodes and is exposed.
  • the MOS circuits are directly beneath the sensor in a vertical dimension.
  • the MOS circuits include a temperature sensor.
  • the temperature sensor comprises a PNP transistor.
  • the MOS circuits include a microcontroller for processing both gas or humidity signals from the gas or humidity sensor and temperature signals from the temperature sensor to provide an enhanced output.
  • the enhanced output is temperature-corrected gas or humidity readings.
  • the senor comprises polyimide deposited over the sensor electrodes.
  • the MOS circuits include an A-to-D converter connected between the sensor electrodes and the processor.
  • the A-to-D converter comprises an array of dummy capacitors with a constant topography surrounding active A-to-D converter capacitors.
  • said diode is formed in a deep trench to a lower interconnect level laterally of the sensor electrodes.
  • the device comprises a photo-detector diode.
  • said diode is in a deep trench in a lower interconnect level laterally of the sensor electrodes.
  • the MOS circuits include a wireless transceiver.
  • the wireless transceiver is for communication with other nodes in a network, and it comprises a means for switching channel frequency according to a low frequency channel switching scheme upon detection of interference.
  • an interconnect level includes a low noise amplifier.
  • the low noise amplifier comprises a strained silicon region beneath a conductor.
  • the strained silicon is in a fifth or sixth interconnect level above the substrate.
  • the senor comprises a detecting element connected between pads on an upper surface of the device.
  • the element is a gas-sensing thin film.
  • the element is of zinc oxide composition.
  • said element detects sound and the MOS circuits comprise an audio processor for processing signals from the elements.
  • the method comprising the steps of: fabricating the MOS circuits in the substrate, fabricating the interconnect levels in successive fabrication cycles according to interconnect design to interconnect the MOS circuits, and fabricating the sensor electrodes and dielectric in a final interconnect level.
  • the method comprises the further step of depositing a passivation layer over the top interconnect level.
  • the method comprises the steps of depositing an etch stop layer over each layer of dielectric in the interconnect levels, and depositing etch stop material over the top interconnect level dielectric to provide a passivation layer.
  • porous oxide is provided as a dielectric in lower interconnect levels and regular oxide is used as a dielectric in upper interconnect levels.
  • a strained low noise amplifier is deposited in an upper interconnect level, said amplifier comprising a strained silicon region.
  • FIG. 1 is a block diagram of a single-chip wireless sensor device of the invention
  • Fig. 2 is a flow diagram illustrating a process for producing the device
  • Fig. 3(a) is a cross-sectional view of the device
  • Fig. 3(b) is a plan view of sensing electrodes
  • Fig. 3(c) is a diagram showing extent of a fringe field between the electrodes
  • Fig. 4 is a schematic of an A-to-D converter of the device
  • Fig. 5 is a diagram showing a sensor component of an alternative embodiment
  • Figs. 6 and 7 are cross-sectional views of alternative sensor components
  • Fig. 8 is a diagram of a potting arrangement for final packaging
  • Fig. 9 is a circuit diagram of a 12-bit SAR A-to-D converter of the sensor device.
  • Fig. 10 is a layout view of the capacitor array for the SAR converter
  • Fig. 11 is a block diagram of a microcontroller of the device.
  • Fig. 12 is cross-sectional diagram showing a sub-surface cun-ent flow path in a strained-silicon transistor of the device
  • Fig. 13 is a diagram illustrating frequency selection of a wireless transceiver
  • Fig. 14 shows a communication scheme for a device of the invention.
  • Fig. 15 is a cross-sectional diagram of a gas sensing device
  • Fig. 16 is a schematic cross-sectional diagram of an audio sensor
  • Fig. 17 is a cross-sectional view of an LED and photo-diode of a device of one embodiment
  • a single chip wireless sensor 1 comprises a microcontroller 2 connected by a transmit/receive interface 3 to a wireless antenna 4.
  • the microcontroller 2 is also connected to an 8kB RAM 5, a USB interface 6, an RS232 interface 8, 64kB flash memory 9, and a 32kHz crystal 10.
  • the device 1 senses humidity and temperature, and a humidity sensor 11 is connected by an 18 bit ⁇ A-to-D converter 12 to the microcontroller 2 and a temperature sensor 13 is connected by a 12 bit SAR A-to-D converter 14 to the microcontroller 2.
  • the device 1 is a single integrated chip manufactured in a single process in which both the electronics and sensor components are manufactured using standard CMOS processing techniques, applied to achieve both electronic and sensing components in an integrated process.
  • the manufacturing process 20 is now described in more detail referring to Figs. 2, 3(a), 3(b) and 3(c), and the steps are 21 to 27 inclusive.
  • a substrate 41 of silicon is processed with CMOS wells, isolation oxidation, poly- silicon, and implants to form MOS components, as is well known in CMOS processing. Also, in the substrate a temperature-sensitive PNP transistor is formed to provide the sensor 13.
  • Second, and third interconnect levels 42 are formed. This involves three cycles of chemical vapour deposition (CND) deposition of a porous low-K silicon dioxide dielectric 42(a), and etching and copper plating operations to provide interconnect tracks 42(b). Each cycle finishes in deposition of an etch stop layer 42(c) for limiting the extent of etching in the next cycle.
  • the etch stop material is silicon nitride Si ⁇ 4 .
  • the silicon dioxide, the interconnect metal, and the etch stop of each cycle forms a first interconnect three-level stack 42.
  • the use of a low-K dielectric allows low capacitance for faster signal transfer between components.
  • Fourth and fifth interconnect levels 43 are formed. There are a further two cycles of dielectric deposition and metal interconnect plating. However, in these two cycles the dielectric is "regular" SiO 2 (non-porous) 43(a) for better structural strength, to counteract the weaker mechanical strength of the porous dielectric in the lower levels 42. Again, these cycles involve standard CMOS techniques.
  • the fifth level includes a heating element 43(b) with an internal temperature monitor for instantaneous heating and purging of the humidity sensor 11 with immediate temperature monitoring. Also, as part of developing the fourth and fifth levels, the process adds a thin metal plate for a capacitor top metal (CTM) with a thin layer (0.04 ⁇ m) SiO 2 dielectric between them to form mixed signal metal-insulator-metal (MIM) capacitors for both of the A-to-D converters.
  • CTM capacitor top metal
  • MIM mixed signal metal-insulator-metal
  • An interconnect/sensing layer 44 is formed. This is simply a next iteration or cycle following from the previous interconnect and plating cycles and indeed the dielectric is the same as for the immediately preceding cycles, "regular" SiO 2 .
  • humidity-sensing ⁇ apacitive interdigitated fingers (electrodes) 45 and reference capactive interdigitated fingers (electrodes) 46 are formed.
  • the size and spacing of the fingers is chosen to suit the application. In this embodiment the fingers 45 and 46 have a spacing of 0.5 ⁇ m. The arrangement is shown more clearly in Fig. 3(b).
  • Each actual capacitive structure is about the size of a bond pad, allowing each finger to have a total length of 4000 ⁇ m. For a metal thickness of 1 ⁇ m this gives a sensor capacitance of 0.276 pF. However, the capacitance between two closely-spaced narrow conductors can be about 10% to 30% greater than the simple parallel plate calculated value, due to fringing components.
  • a passivation layer 48 is deposited by CND in a manner similar to that of the conventional etch stop layers as it is also of Si 3 ⁇ 4 .
  • the passivation layer 48 is, however, approximately 3-5 ⁇ m thick to offer physical protection and a moisture barrier for the device 1.
  • That part of the passivation layer 48 over the sensing electrodes 45 is etched to a depth of 90% to leave a thin Si 3 N 4 layer 48(a) of approximately 0.1 ⁇ m depth over the sensing electrodes.
  • the sensor 1 relies on this fringe component 55 of the field between the electrodes.
  • the fringe component is about 25 to 50fF.
  • This converter is shown in Fig. 4 in which the sensing fingers 45 are Cs and the reference fingers 46 are Cr.
  • These capacitances form the differential front-end of a second-order over-sampled sigma-delta modulator, illustrating the level of integration between the sensor and converter components.
  • Vr and Ns provide scale and offset compensation. Very high resolution is achieved by trading off the number of samples per second and over-sampling ratio using the decimation filters.
  • porous material 50 is deposited (or printed) on top of passivation 51, eliminating extra etching steps.
  • the passivation thickness is about 3 ⁇ m for example, then the spacing of the sensor capacitor fingers 45 must be increased to about 5 ⁇ m or more in order that the fringe capacitance component still represents a measurable ratio of the total capacitance.
  • total capacitance is now reduced to about 27fF, with the variable fringing component now being in the region of 3 to 5 fF.
  • Humidity variations of 1% or 2% now produce capacitance variations of less than a femtoFarad - still detectable by the highly over-sampled differential sigma-delta high-resolution converter. 18 bits of resolution also provides a very large dynamic range, enabling the converter to easily cope with the highly variable and non-linear capacitance-versus-humidity characteristics of different oxides and different pore sizes from wafer to wafer and lot to lot.
  • CMOS processing is used, with no extra processing steps required.
  • Polyimide is often used as a 'stress relief coating layer on silicon chips.
  • the polyimide placement is usually determined by a slightly oversized version of the bond-pad mask.
  • the polyimide mask includes an extra opening to eliminate polyamide 60 from over the reference capacitor. Since polyimide is porous, the portion over the sensing capacitor now experiences a minute change in capacitance versus humidity.
  • porous low-K oxide dielectric is used in all interconnect levels of the device, so the sensor device has a porous low-K dielectric
  • This embodiment has the advantage of using the standard CMOS process with no extra masks required. However, it allows access by the moisture to the capacitive fingers 71. However, for many applications this is not a problem, for example a low-humidity office environment where the sensor only experiences a few millivolts applied for a few milliseconds once every few minutes.
  • Fig. 8 shows a simple potting arrangement for enclosing the single-chip wireless sensor.
  • the sensor 1 is bonded to a battery 80 by conductive adhesive 81 and there is encapsulation 82.
  • a former is used to keep the area over the sensing component clear. All other areas are enclosed by the encapsulant 82, which affords physical protection, as well as protection of the chip and battery terminals from corrosion or electrolytic degradation if exposed continuously to high moisture environments. No metal is exposed anywhere, except for an RF antenna wire 83.
  • a substrate PNP temperature sensor 13 is also developed as an integral part of the substrate 41, as shown in Fig. 3(a). This relies on the well-known -2.2m V/°C Vbe characteristic of the base emitter junction.
  • the microcontroller By having a combination of humidity and temperature sensors in the one device, there can be calculation of an enhanced reading by the microcontroller, namely dew point.
  • the 12-bit SAR converter 14 is shown. This measures the Vbe voltage of the P ⁇ P, or the temperature-dependent resistance of the metal heater monitor in a bridge configuration as shown.
  • the converter achieves 12 bit resolution without any calibration circuits, as follows.
  • the capacitor array for the converter 14 is in the center of the level, and it is surrounded by eight similar dummy arrays 90 to ensure constant topography and excellent matching of the key array capacitors in the converter 14.
  • the array is segmented into 7 upper bits and a 5- bit sub-DAC via coupling capacitor Cc. This, together with a small unit capacitor size of 7 x 7 ⁇ m, keeps the entire array capacitance (Cs) at around 8pF.
  • the capacitors have very small parasitic capacitances to the substrate, simplifyir-Lg matching of the ratioed capacitors.
  • the Metal-Insulator-Metal (MIM) structure of these capacitors results in low voltage and temperature coefficients and parasitic resistances.
  • the time-interval counter and part of the microcontroller's interrupt logic are implemented on thick-oxide 3.3V transistors, as shown in Fig 11.
  • the microcontroller On wakeup from power-down, the microcontroller also achieves reduction of noise and substrate crosstalk by operating the sensors, converters, and radio transceiver sequentially.
  • the LNA is designed to have extra low power and low noise operation.
  • This is enabled by copper inductors on the fifth or sixth levels, and the use of strained silicon MOS devices for the front-end LNA, see Fig. 12.
  • This diagram shows a thin layer of Silicon-Germanium 100, over which there is a thin strained silicon layer 101, with higher carrier mobility than regular silicon.
  • the polysilicon gate 102 creates a channel in the strained silicon region.
  • the LNA can therefore be biased at lower currents for the same gain, saving battery power.
  • Copper has lower resistance than aluminium, giving a higher Q-factor (resulting in higher receiver gain).
  • the fifth or sixth level of copper is also thicker (lower resistance), and further away from the substrate (less parasitic capacitances).
  • the device 1 forms a node in a wireless network of nodes. This could be a simple point-to-point link or a star or mesh network.
  • a fixed frequency is used by all nodes and the wireless interface 3 provides a slow frequency hopping scheme to circumvent interferers. It operates by all nodes using the same frequency initially.
  • the nodes move to a different frequency according to an algorithm illustrated in Fig. 13. There follows synchronisation of all nodes.
  • nodes are pre-programmed with the hop sequence for the frequency-hopping scheme to work. Further, they must all be initialised to the same channel so that they can "hop together", typically after installation or battery replacement.
  • the installer upon installation (or battery replacement), the installer manually puts the node into "initialise” mode, by, for example, pressing a button.
  • the node then switches on its receiver and "listens” for a nearby node transmission (or master beacon), on channel 0 for example. If it receives nothing after an appropriate time, for example a few seconds or minutes (because the current channel might be blocked), it steps to the next channel in the sequence, and again waits and listens.
  • it should receive a beacon or data packet from a neighbouring node; it can then re-synchronise its timer, request the hop interval timing, join the sequence, and go to sleep until the next hop and transmit period.
  • This initialisation method means the node has to stay "on” in full-power receive mode just once at installation; it can then revert to sleep mode for 99.9% of the time (as defined in the 802.15.4 standard) for the 1 to 3 year lifetime of the battery. Since the 802.15.4 standard allows for sleep periods of up to about 4 minutes, the node could be in full-power receive mode for this duration. In practice this is unlikely, however, since the installer will know about this period. Using a spectrum analyser (or handheld wireless 'sniffer'), he can roughly predict when the next beacon transmission is due, and press the 'initialise' button just before this.
  • this diagram shows an example of use of the slow hopping scheme. It is used on a long-distance (200m) link 115 between two buildings 120 and 125 (using a directional 14dBi antenna on a gateway node 126 linked with a computer 127).
  • a standard 802.15.4 Zigbee fixed-channel star network of nodes 121 is implemented within the first building 120. This enables multi-vendor interoperable nodes to be installed in a star-network plant monitoring application, whereas the slow- hopping algorithm is employed on the long-distance critical link, which is more at risk of interference.
  • the entire humidity sensor since the entire humidity sensor is fabricated in a standard CMOS process, it can be tested - and calibrated - at the normal wafer-level test before wafers are shipped. This takes advantage of the fact that wafer probe and factory test areas are generally operated at a precise humidity level, for example 40% relative humidity.
  • This known value can be stored in on-chip Flash EEPROM memory for later use by the microcontroller in correctly calibrating the output value under software control, or it can be used in a non-Flash-EEPROM version of the chip to blow poly fuses to calibrate the sensor at 40% RH.
  • This 1 -point calibration may be sufficient for many applications, e.g. office air-conditioning control around a setpoint, typically 40%.
  • a second calibration point may be required. This is achieved by doing a "second-pass" wafer probe, in an enclosed chamber at 85% RH for example, or a dry-nitrogen dessicant chamber (0.001% RH). Although the second pass wafer test adds some additional cost, it is significantly less than package based testing.
  • a thin film 130 of zinc oxide and ferric oxide is deposited over passivation 131 at the location of one of the differential capacitors 132 of the 18-bit Sigma-Delta A-to-D converter 12.
  • These oxides are synthesized by a sol-gel process, heated to about 120°C to 200°C then deposited by hybrid-ink-jet deposition.
  • the thin-film means that small finger spacings can be used in the sensor structure, and the high-resolution A-to-D converter means that small sensor structures can be used and still result in detectable minute changes of capacitance, even at room temperature operation.
  • Fig. 16 shows an alternative embodiment, in which ferric-oxide/zinc-oxide 140 is deposited on top oxide or passivation 141, but is connected directly to electrodes 142 in the top metal layers, forming a resistor whose value can be determined as part of a bridge circuit by the 18 -bit converter.
  • the device architecture and production process may be adapted for sensing different gases, such as using palladium for hydrogen sensing, Zirconia for S0 , H 2 S, or Plasticised Polyvinyl chloride for N0 2 , and W0 3 for iso-butane.
  • gases such as using palladium for hydrogen sensing, Zirconia for S0 , H 2 S, or Plasticised Polyvinyl chloride for N0 2 , and W0 3 for iso-butane.
  • both the conductivity and dielectric constant of the sensing material is changed by the ingressing gas, by adsorbtion, or physisorbtion, or chemisorbtion. Therefore the embodiments of 15 - capacitive - and 16 - resistive - are used alternately or together in conjunction with the on-chip tightly integrated high resolution converter to achieve very low ppm gas concentration measurements.
  • a piezo-electric polymer may be applied in the configuration shown in Fig. 16 for sound sensitivity. Transduction is predominantly based on conductivity change. In this case, at the MOS circuit level a bridge circuit with buffer driving the 18-bit A-to-D converter is employed to capture the audio signal.
  • An audio sensor is a useful feature on a remote wireless node, for example to "listen” if a motor is running, if an alarm bell is ringing. Arrangements are needed for this audio due to the 0.1% duty cycle of IEEE802.15.4; the 250Kb/s max data rate in the 802.15.4 2.4GHz band corresponds to a sustained constant data rate of 250 b/s at 0.1% duty cycle.
  • a variable-bit-rate audio compressor block (VBR) is employed to achieve 15:1 or better compression ratio, achieving an effective audio bit-rate of 3.75Kb/s - sufficient for many industrial low-grade audio requirements.
  • the device may also include an optical emitter 150 and detector 151.
  • Highly-directional deep anisotropic etching is employed at the end of normal processing to fully etch away all six or seven layers of dielectric to expose a photodiode light sensor 151, a large PN junction, 200um x 500um, which collects photons and generates a corresponding electrical current.
  • the etch also reveals a porous silicon region 150 in this embodiment, created at the start of the process by electrochemical etching of the substrate in this particular region. Passing current through this makes it function as a light emitting diode (LED) due to the well known luminescence property of porous silicon. Isolation trenches placed around the porous region can minimize any currents leaking to the substrate and improve the light efficiency.
  • LED light emitting diode
  • Electrochemical etching to fonn porous silicon is well known to those skilled in the art, and available on some CMOS processes, but is non-standard on most CMOS processes.
  • An alternative LED construction is a doped polymer organic light emitting device.
  • Hybrid Ink-jet printing is used to directly deposit patterned luminescent doped-polymer films, for example polyvinylcarbazol (PVK) film, onto electrodes in the manner shown in Fig. 16.
  • PVK polyvinylcarbazol
  • the invention is not limited to the embodiments described but may be varied in construction and detail.
  • conductors other than copper may be used for the interconnects, such as aluminium.
  • the sensor device may be a "stripped down" version of the sensor, a "humidity-to-digital” sensor chip, having no radio or microcontroller or flash memory.
  • calibration of the A-to-D and sensor is achieved by blowing various poly fuses in the voltage reference circuit and capacitor array. It should be noted that testing need not involve testing every code of the A-to- D, thereby simplifying testing significantly, and reducing cost.
  • strained silicon as a low noise amplifier, low-frequency channel selection/hopping, SAR with replication of the capacitor array, porous silicon LED, audio piezo-electric polymer microphone sensor, audio compression and transmission at low duty cycle, the microcontroller features.

Abstract

An intergrated sensor device and method of manufacturing said device comprising: MOS circuits in a semiconductor substrate, interconnect levels with interconnect conductors and insulating dielectric, said levels being over the substrate and interconnecting the MOS circuits, the interconnect levels incorporating a sensor having electrodes embedded in the interconnect dielectric, and the MOS circuits including a processor for processing signals from the sensor electrodes.

Description

"An integrated electronic sensor"
INTRODUCTION
Field of the Invention
The invention relates to electronic sensors.
Prior Art Discussion
One of the main driving forces in the electronics industry is the desire to achieve greater integration of functionality so that production is more automated and per-unit cost reduced. An added benefit is, of course, decreased size and thus higher circuit density. Most importantly, for battery applications, higher integration generally results in lower power, due to reduced parasitic capacitances.
However in the field of sensors, and in particular wireless sensors, greater integration has been slow because of the difficulties encountered in integration of microcontroller, A-to-D converter (ADC), memory, RF transceiver, and sensor elements in the one integrated sensor device. These difficulties have arisen because of incompatibilities of materials processing for the various elements. For example, sensor elements have conventionally been manufactured on ceramic or glass substrates and can not be easily integrated on silicon. RF transceivers have typically been made from bipolar transistors, which are difficult to integrate with other technologies such as CMOS. Also, many CMOS high-resolution ADCs are made using poly-poly capacitors, which suffer from substrate parasitics, strain, and mis-match effects. Also, the aluminium metallisation used in IC processing is prone to corrosion, thus limiting usefulness for some types of sensor applications.
US6724612 and US6690569 describe sensor devices having both electronic and sensing components, the latter being capacitive electrodes. However, the electrodes require platinum or gold coating, and deposition of a polymer as a moisture-sensing dielectric. This processing is not amenable to high- volume semiconductor processing. The invention addresses these issues.
SUMMARY OF THE INVENTION
According to the invention, there is provided an integrated sensor device comprising:
MOS circuits in a semiconductor substrate, interconnect levels with interconnect conductors and insulating dielectric, said levels being over the substrate and interconnecting the MOS circuits, the interconnect levels incorporating a sensor having electrodes embedded in the interconnect dielectric, and the MOS circuits including a processor for processing signals from the sensor electrodes.
In one embodiment, the sensor comprises a porous oxide for ingress of a gas or humidity being sensed.
In another embodiment, the porous oxide is carbon-doped SiO2.
In a further embodiment, the sensor is a capactive sensor.
In one embodiment, the sensor comprises a passivation layer over the sensor electrodes.
In another embodiment, the porous oxide is deposited on the passivation layer, and the MOS circuits detect changes in a fringe field between the electrodes.
In a further embodiment, comprises etch stop layers between the interconnect levels, and the passivation layer is of the same composition as the etch stop material. In one embodiment, the passivation layer is of Si3N4 composition.
In another embodiment, the passivation layer is recessed over the sensing electrodes.
In a further embodiment, there is a porous oxide film in the recess.
In one embodiment, the porous oxide is between the electrodes and is exposed.
In another embodiment, the MOS circuits are directly beneath the sensor in a vertical dimension.
In a further embodiment, the MOS circuits include a temperature sensor.
In one embodiment, the temperature sensor comprises a PNP transistor.
In another embodiment, the MOS circuits include a microcontroller for processing both gas or humidity signals from the gas or humidity sensor and temperature signals from the temperature sensor to provide an enhanced output.
In a further embodiment, the enhanced output is temperature-corrected gas or humidity readings.
In one embodiment, the sensor comprises polyimide deposited over the sensor electrodes.
In another embodiment, the MOS circuits include an A-to-D converter connected between the sensor electrodes and the processor.
In a further embodiment, the A-to-D converter comprises an array of dummy capacitors with a constant topography surrounding active A-to-D converter capacitors.
In one embodiment, further comprises a light emitting diode. In another embodiment, said diode is formed in a deep trench to a lower interconnect level laterally of the sensor electrodes.
In a further embodiment, the device comprises a photo-detector diode.
In one embodiment, said diode is in a deep trench in a lower interconnect level laterally of the sensor electrodes.
In another embodiment, the MOS circuits include a wireless transceiver.
In a further embodiment, the wireless transceiver is for communication with other nodes in a network, and it comprises a means for switching channel frequency according to a low frequency channel switching scheme upon detection of interference.
In one embodiment, an interconnect level includes a low noise amplifier.
In another embodiment, the low noise amplifier comprises a strained silicon region beneath a conductor.
In a further embodiment, the strained silicon is in a fifth or sixth interconnect level above the substrate.
In one embodiment, the sensor comprises a detecting element connected between pads on an upper surface of the device.
In another embodiment, the element is a gas-sensing thin film.
In a further embodiment, the element is of zinc oxide composition.
In one embodiment, said element detects sound and the MOS circuits comprise an audio processor for processing signals from the elements. In another aspect of the invention, there is provided a method of producing a sensor device of any of the above embodiments, the method comprising the steps of: fabricating the MOS circuits in the substrate, fabricating the interconnect levels in successive fabrication cycles according to interconnect design to interconnect the MOS circuits, and fabricating the sensor electrodes and dielectric in a final interconnect level.
In one embodiment, the method comprises the further step of depositing a passivation layer over the top interconnect level.
In another embodiment, the method comprises the steps of depositing an etch stop layer over each layer of dielectric in the interconnect levels, and depositing etch stop material over the top interconnect level dielectric to provide a passivation layer.
In a further embodiment, porous oxide is provided as a dielectric in lower interconnect levels and regular oxide is used as a dielectric in upper interconnect levels.
In one embodiment, a strained low noise amplifier is deposited in an upper interconnect level, said amplifier comprising a strained silicon region.
DETAILED DESCRIPTION OF THE INVENTION
Brief Description of the Drawings
The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which:- Fig. 1 is a block diagram of a single-chip wireless sensor device of the invention;
Fig. 2 is a flow diagram illustrating a process for producing the device;
Fig. 3(a) is a cross-sectional view of the device, Fig. 3(b) is a plan view of sensing electrodes; and Fig. 3(c) is a diagram showing extent of a fringe field between the electrodes;
Fig. 4 is a schematic of an A-to-D converter of the device;
Fig. 5 is a diagram showing a sensor component of an alternative embodiment;
Figs. 6 and 7 are cross-sectional views of alternative sensor components;
Fig. 8 is a diagram of a potting arrangement for final packaging;
Fig. 9 is a circuit diagram of a 12-bit SAR A-to-D converter of the sensor device;
Fig. 10 is a layout view of the capacitor array for the SAR converter;
Fig. 11 is a block diagram of a microcontroller of the device;
Fig. 12 is cross-sectional diagram showing a sub-surface cun-ent flow path in a strained-silicon transistor of the device;
Fig. 13 is a diagram illustrating frequency selection of a wireless transceiver;
Fig. 14 shows a communication scheme for a device of the invention.
Fig. 15 is a cross-sectional diagram of a gas sensing device; Fig. 16 is a schematic cross-sectional diagram of an audio sensor; and
Fig. 17 is a cross-sectional view of an LED and photo-diode of a device of one embodiment
Description of the Embodiments
Gas/humidity Sensor Embodiment
Referring to Fig. 1 a single chip wireless sensor 1 comprises a microcontroller 2 connected by a transmit/receive interface 3 to a wireless antenna 4. The microcontroller 2 is also connected to an 8kB RAM 5, a USB interface 6, an RS232 interface 8, 64kB flash memory 9, and a 32kHz crystal 10. In this embodiment, the device 1 senses humidity and temperature, and a humidity sensor 11 is connected by an 18 bit ∑Δ A-to-D converter 12 to the microcontroller 2 and a temperature sensor 13 is connected by a 12 bit SAR A-to-D converter 14 to the microcontroller 2.
The device 1 is a single integrated chip manufactured in a single process in which both the electronics and sensor components are manufactured using standard CMOS processing techniques, applied to achieve both electronic and sensing components in an integrated process.
The manufacturing process 20 is now described in more detail referring to Figs. 2, 3(a), 3(b) and 3(c), and the steps are 21 to 27 inclusive.
21, Front End Processing
A substrate 41 of silicon is processed with CMOS wells, isolation oxidation, poly- silicon, and implants to form MOS components, as is well known in CMOS processing. Also, in the substrate a temperature-sensitive PNP transistor is formed to provide the sensor 13.
22. Lower Interconnect and Dielectric Deposition First, second, and third interconnect levels 42 are formed. This involves three cycles of chemical vapour deposition (CND) deposition of a porous low-K silicon dioxide dielectric 42(a), and etching and copper plating operations to provide interconnect tracks 42(b). Each cycle finishes in deposition of an etch stop layer 42(c) for limiting the extent of etching in the next cycle. The etch stop material is silicon nitride Si Ν4. The silicon dioxide, the interconnect metal, and the etch stop of each cycle forms a first interconnect three-level stack 42. The use of a low-K dielectric allows low capacitance for faster signal transfer between components.
23, Upper Interconnect and CND Dielectric Deposition
Fourth and fifth interconnect levels 43 are formed. There are a further two cycles of dielectric deposition and metal interconnect plating. However, in these two cycles the dielectric is "regular" SiO2 (non-porous) 43(a) for better structural strength, to counteract the weaker mechanical strength of the porous dielectric in the lower levels 42. Again, these cycles involve standard CMOS techniques.
The fifth level includes a heating element 43(b) with an internal temperature monitor for instantaneous heating and purging of the humidity sensor 11 with immediate temperature monitoring. Also, as part of developing the fourth and fifth levels, the process adds a thin metal plate for a capacitor top metal (CTM) with a thin layer (0.04μm) SiO2 dielectric between them to form mixed signal metal-insulator-metal (MIM) capacitors for both of the A-to-D converters.
24, CND Deposition of SiO7. Sensing level
An interconnect/sensing layer 44 is formed. This is simply a next iteration or cycle following from the previous interconnect and plating cycles and indeed the dielectric is the same as for the immediately preceding cycles, "regular" SiO2. However as an integral part of plating the top interconnect layer 44 humidity-sensing ^apacitive interdigitated fingers (electrodes) 45 and reference capactive interdigitated fingers (electrodes) 46 are formed. The size and spacing of the fingers is chosen to suit the application. In this embodiment the fingers 45 and 46 have a spacing of 0.5μm. The arrangement is shown more clearly in Fig. 3(b). Using oxide permittivity Kox of 3.9, this results in capacitance of: kse^ = 3.9 * 8.8SxlO-" = n nπnnΛOTT/tr 2 _ Λ Agn JP /.. Cox = ^≥-fo. = J-y °-°JΛi 6 U = 0.000069F/m2 = 0.069 fFlμm2 Tox 0.5x10-6
Each actual capacitive structure is about the size of a bond pad, allowing each finger to have a total length of 4000 μm. For a metal thickness of 1 μm this gives a sensor capacitance of 0.276 pF. However, the capacitance between two closely-spaced narrow conductors can be about 10% to 30% greater than the simple parallel plate calculated value, due to fringing components.
25, Deposition of Si3N Passivation Layer
A passivation layer 48 is deposited by CND in a manner similar to that of the conventional etch stop layers as it is also of Si3Ν4. The passivation layer 48 is, however, approximately 3-5μm thick to offer physical protection and a moisture barrier for the device 1.
26, Etch Passivation over Sensing Electrodes
That part of the passivation layer 48 over the sensing electrodes 45 is etched to a depth of 90% to leave a thin Si3N4 layer 48(a) of approximately 0.1 μm depth over the sensing electrodes.
27, CND Deposition of Porous Oxide
The same material as is used as a dielectric in the first three levels is now deposited by CND in the recess formed in step 26. This is a moisture-sensing film 49 having a large specific area. Ingress of gas or moisture causes a change in pennittivity of the porous dielectric. This causes a change in capacitance of the underlying sensing electrodes 45. It will be appreciated from the above that standard Deep- Sub-Micron CMOS processing techniques are used, thus achieving fully integrated production. The sensor is made simultaneously with the rest of the chip, using the same dielectric and interconnect metal layers. This 'standard CMOS' method is very advantageous to the high- volume manufacturability of this sensor 1.
This approach has not apparently been attempted heretofore because of the perception that such a sensor would require polymers, and gold or platinum plating and/or other non-standard materials which would be regarded as contaminants in a modern CMOS wafer fabrication plant. Developments in SiO2-based compositions to achieve reduced capacitance break up the internal lattice structure. This makes them porous and amenable to moisture or gas penetration. Also, the silicon nitride (Si3N4) of CMOS processing to achieve an etch stop layer is used in the sensor architecture to act as a barrier layer to protect the integrated device. In the above embodiment the Si-sN . layer is over the sensing component and it acts as a barrier to ingress of the moisture being sensed as such penetration may corrode the electrodes in high humidity environments. The sensing is therefore based on use of the spring effect, as set out below.
Use of Device 1
In use, moisture ingresses into the film 49 so that it affects its dielectric constant, and therefore the fringe field, between the sensing fingers 45. This is illustrated by the lines 55 in Fig. 3(c). This occurs even though the moisture is blocked by the thin part 48(a) of the layer 48 from accessing the spaces between the sensing fingers 45.
The sensor 1 relies on this fringe component 55 of the field between the electrodes. For the 4000μm, 0.27pF structure described, the fringe component is about 25 to 50fF. Because of the close proximity of the 18-bit ∑Δ A-to-D converter (immediately beneath the sensor) very small capacitance changes are detectable, even in the fringe field. This converter is shown in Fig. 4 in which the sensing fingers 45 are Cs and the reference fingers 46 are Cr. These capacitances form the differential front-end of a second-order over-sampled sigma-delta modulator, illustrating the level of integration between the sensor and converter components. Vr and Ns provide scale and offset compensation. Very high resolution is achieved by trading off the number of samples per second and over-sampling ratio using the decimation filters.
Referring to Fig. 5, in this embodiment, porous material 50 is deposited (or printed) on top of passivation 51, eliminating extra etching steps. However, if the passivation thickness is about 3μm for example, then the spacing of the sensor capacitor fingers 45 must be increased to about 5μm or more in order that the fringe capacitance component still represents a measurable ratio of the total capacitance. For the 4000μm sensor structure, total capacitance is now reduced to about 27fF, with the variable fringing component now being in the region of 3 to 5 fF. Humidity variations of 1% or 2% now produce capacitance variations of less than a femtoFarad - still detectable by the highly over-sampled differential sigma-delta high-resolution converter. 18 bits of resolution also provides a very large dynamic range, enabling the converter to easily cope with the highly variable and non-linear capacitance-versus-humidity characteristics of different oxides and different pore sizes from wafer to wafer and lot to lot.
Referring to Fig. 6, in this embodiment, standard CMOS processing is used, with no extra processing steps required. Polyimide is often used as a 'stress relief coating layer on silicon chips. The polyimide placement is usually determined by a slightly oversized version of the bond-pad mask. In this example, the polyimide mask includes an extra opening to eliminate polyamide 60 from over the reference capacitor. Since polyimide is porous, the portion over the sensing capacitor now experiences a minute change in capacitance versus humidity.
Referring to Fig. 7, in this embodiment porous low-K oxide dielectric is used in all interconnect levels of the device, so the sensor device has a porous low-K dielectric
70 between capacitive interdigitated fingers 71. By placing a 'dummy' bond pad passivation opening over the sensor structure, the surface 72 above the sensing fingers
71 is exposed for ingress of moisture into the dielectric between the fingers during the bond-pad etch. This leaves passivation 73 over the full area except the sensing capacitive fingers 71. This embodiment has the advantage of using the standard CMOS process with no extra masks required. However, it allows access by the moisture to the capacitive fingers 71. However, for many applications this is not a problem, for example a low-humidity office environment where the sensor only experiences a few millivolts applied for a few milliseconds once every few minutes.
Fig. 8 shows a simple potting arrangement for enclosing the single-chip wireless sensor. The sensor 1 is bonded to a battery 80 by conductive adhesive 81 and there is encapsulation 82. A former is used to keep the area over the sensing component clear. All other areas are enclosed by the encapsulant 82, which affords physical protection, as well as protection of the chip and battery terminals from corrosion or electrolytic degradation if exposed continuously to high moisture environments. No metal is exposed anywhere, except for an RF antenna wire 83.
Alternatively, there may be no encapsulation if physical protection is less important and/or if response time to temperature variations is more important.
Temperature Sensors
In addition to the metal heater temperature sensor 43(b) described above, a substrate PNP temperature sensor 13 is also developed as an integral part of the substrate 41, as shown in Fig. 3(a). This relies on the well-known -2.2m V/°C Vbe characteristic of the base emitter junction. By having a combination of humidity and temperature sensors in the one device, there can be calculation of an enhanced reading by the microcontroller, namely dew point. These, together with the microcontroller 2 and the flash memory 9 allow use of look-up tables for scaling and calibration, to achieve accuracy to within 0.5°C.
Referring to Fig. 9, the 12-bit SAR converter 14 is shown. This measures the Vbe voltage of the PΝP, or the temperature-dependent resistance of the metal heater monitor in a bridge configuration as shown. The converter achieves 12 bit resolution without any calibration circuits, as follows. Referring to Fig. 10 the capacitor array for the converter 14 is in the center of the level, and it is surrounded by eight similar dummy arrays 90 to ensure constant topography and excellent matching of the key array capacitors in the converter 14. The array is segmented into 7 upper bits and a 5- bit sub-DAC via coupling capacitor Cc. This, together with a small unit capacitor size of 7 x 7 μm, keeps the entire array capacitance (Cs) at around 8pF. small enough that it can be driven efficiently with an on-chip buffer amplifier as shown, and also small enough that global mismatches due to gradients in oxide thickness or other process parameters are minimized. At a sampling frequency of lOOKHz, the kT/C noise figure is 140nV, well below the 12-bit LSB size Being on Metal 5 (fifth level), the capacitors have very small parasitic capacitances to the substrate, simplifyir-Lg matching of the ratioed capacitors. The Metal-Insulator-Metal (MIM) structure of these capacitors results in low voltage and temperature coefficients and parasitic resistances.
Flash Microcontroller:
Having the 8-bit microcontroller 2 and the 64KB Flash memory 9 on the same chip as the sensors enables significant improvements in accuracy and functionality. This is because real-time continuous calibration or in-situ calibration over various conditions of temperature is achieved. This amount of memory is also sufficient to accommodate the entire IEEE802.15.4 protocol and Zigbee software stack to perform beacon, peer- to-peer, star and mesh networking, key requirements of modern wireless sensor networks. An on-chip regulator generates 1.2V, which powers most of the microcontroller, memory blocks, and wireless RF transceiver, whicTi are fabricated on thin-oxide minimum geometry devices.
To facilitate lower power, the time-interval counter and part of the microcontroller's interrupt logic are implemented on thick-oxide 3.3V transistors, as shown in Fig 11. This means the regulator can be switched off when the chip is in sleep or power-down mode, eliminating the DC bias curcents of the regulator. This, together with almost- zero sub-threshold leakage of the 3V transistors, results in significant power saving and elongation of battery life. On wakeup from power-down, the microcontroller also achieves reduction of noise and substrate crosstalk by operating the sensors, converters, and radio transceiver sequentially.
Turning now to the wireless transceiver 3, and its low noise amplifier (LNA) in particular, the LNA is designed to have extra low power and low noise operation. This is enabled by copper inductors on the fifth or sixth levels, and the use of strained silicon MOS devices for the front-end LNA, see Fig. 12. This diagram shows a thin layer of Silicon-Germanium 100, over which there is a thin strained silicon layer 101, with higher carrier mobility than regular silicon. The polysilicon gate 102 creates a channel in the strained silicon region. However the majority of the transistor current flows in the sub-surface SiGe region, due to the higher mobility of Germanium, giving lower noise operation and higher gain. The LNA can therefore be biased at lower currents for the same gain, saving battery power. Copper has lower resistance than aluminium, giving a higher Q-factor (resulting in higher receiver gain). The fifth or sixth level of copper is also thicker (lower resistance), and further away from the substrate (less parasitic capacitances).
Referring to Fig. 13, frequency selection for the RF transceiver 3 is shown. The device 1 forms a node in a wireless network of nodes. This could be a simple point-to-point link or a star or mesh network. A fixed frequency is used by all nodes and the wireless interface 3 provides a slow frequency hopping scheme to circumvent interferers. It operates by all nodes using the same frequency initially. Upon a transmission failure indicating possible interference, the nodes move to a different frequency according to an algorithm illustrated in Fig. 13. There follows synchronisation of all nodes.
All nodes are pre-programmed with the hop sequence for the frequency-hopping scheme to work. Further, they must all be initialised to the same channel so that they can "hop together", typically after installation or battery replacement.
In more detail, upon installation (or battery replacement), the installer manually puts the node into "initialise" mode, by, for example, pressing a button. The node then switches on its receiver and "listens" for a nearby node transmission (or master beacon), on channel 0 for example. If it receives nothing after an appropriate time, for example a few seconds or minutes (because the current channel might be blocked), it steps to the next channel in the sequence, and again waits and listens. Eventually by this means it should receive a beacon or data packet from a neighbouring node; it can then re-synchronise its timer, request the hop interval timing, join the sequence, and go to sleep until the next hop and transmit period. This initialisation method means the node has to stay "on" in full-power receive mode just once at installation; it can then revert to sleep mode for 99.9% of the time (as defined in the 802.15.4 standard) for the 1 to 3 year lifetime of the battery. Since the 802.15.4 standard allows for sleep periods of up to about 4 minutes, the node could be in full-power receive mode for this duration. In practice this is unlikely, however, since the installer will know about this period. Using a spectrum analyser (or handheld wireless 'sniffer'), he can roughly predict when the next beacon transmission is due, and press the 'initialise' button just before this.
Referring to Fig. 14 this diagram shows an example of use of the slow hopping scheme. It is used on a long-distance (200m) link 115 between two buildings 120 and 125 (using a directional 14dBi antenna on a gateway node 126 linked with a computer 127). A standard 802.15.4 Zigbee fixed-channel star network of nodes 121 is implemented within the first building 120. This enables multi-vendor interoperable nodes to be installed in a star-network plant monitoring application, whereas the slow- hopping algorithm is employed on the long-distance critical link, which is more at risk of interference.
Testing and Calibration
This is traditionally difficult for humidity sensors, requiring special chambers of controlled humidity, along with special package handling and electrical connections.
In this invention, since the entire humidity sensor is fabricated in a standard CMOS process, it can be tested - and calibrated - at the normal wafer-level test before wafers are shipped. This takes advantage of the fact that wafer probe and factory test areas are generally operated at a precise humidity level, for example 40% relative humidity. This known value can be stored in on-chip Flash EEPROM memory for later use by the microcontroller in correctly calibrating the output value under software control, or it can be used in a non-Flash-EEPROM version of the chip to blow poly fuses to calibrate the sensor at 40% RH. This 1 -point calibration may be sufficient for many applications, e.g. office air-conditioning control around a setpoint, typically 40%. If more accuracy over a wider range of humidity is desired, then a second calibration point may be required. This is achieved by doing a "second-pass" wafer probe, in an enclosed chamber at 85% RH for example, or a dry-nitrogen dessicant chamber (0.001% RH). Although the second pass wafer test adds some additional cost, it is significantly less than package based testing.
Gas Sensing
In another embodiment, illustrated in Fig. 15, a thin film 130 of zinc oxide and ferric oxide is deposited over passivation 131 at the location of one of the differential capacitors 132 of the 18-bit Sigma-Delta A-to-D converter 12. These oxides are synthesized by a sol-gel process, heated to about 120°C to 200°C then deposited by hybrid-ink-jet deposition. The thin-film means that small finger spacings can be used in the sensor structure, and the high-resolution A-to-D converter means that small sensor structures can be used and still result in detectable minute changes of capacitance, even at room temperature operation.
Fig. 16 shows an alternative embodiment, in which ferric-oxide/zinc-oxide 140 is deposited on top oxide or passivation 141, but is connected directly to electrodes 142 in the top metal layers, forming a resistor whose value can be determined as part of a bridge circuit by the 18 -bit converter.
By use of different materials instead of the oxides 130 Fig. 15, the device architecture and production process may be adapted for sensing different gases, such as using palladium for hydrogen sensing, Zirconia for S0 , H2S, or Plasticised Polyvinyl chloride for N02, and W03 for iso-butane. In each case, both the conductivity and dielectric constant of the sensing material is changed by the ingressing gas, by adsorbtion, or physisorbtion, or chemisorbtion. Therefore the embodiments of 15 - capacitive - and 16 - resistive - are used alternately or together in conjunction with the on-chip tightly integrated high resolution converter to achieve very low ppm gas concentration measurements.
Audio Sensors: Alternatively, a piezo-electric polymer may be applied in the configuration shown in Fig. 16 for sound sensitivity. Transduction is predominantly based on conductivity change. In this case, at the MOS circuit level a bridge circuit with buffer driving the 18-bit A-to-D converter is employed to capture the audio signal.
An audio sensor (microphone) is a useful feature on a remote wireless node, for example to "listen" if a motor is running, if an alarm bell is ringing. Arrangements are needed for this audio due to the 0.1% duty cycle of IEEE802.15.4; the 250Kb/s max data rate in the 802.15.4 2.4GHz band corresponds to a sustained constant data rate of 250 b/s at 0.1% duty cycle. A variable-bit-rate audio compressor block (VBR) is employed to achieve 15:1 or better compression ratio, achieving an effective audio bit-rate of 3.75Kb/s - sufficient for many industrial low-grade audio requirements.
Optical sensors
Referring to Fig. 17 the device may also include an optical emitter 150 and detector 151. Highly-directional deep anisotropic etching is employed at the end of normal processing to fully etch away all six or seven layers of dielectric to expose a photodiode light sensor 151, a large PN junction, 200um x 500um, which collects photons and generates a corresponding electrical current.
The etch also reveals a porous silicon region 150 in this embodiment, created at the start of the process by electrochemical etching of the substrate in this particular region. Passing current through this makes it function as a light emitting diode (LED) due to the well known luminescence property of porous silicon. Isolation trenches placed around the porous region can minimize any currents leaking to the substrate and improve the light efficiency.
Electrochemical etching to fonn porous silicon is well known to those skilled in the art, and available on some CMOS processes, but is non-standard on most CMOS processes. An alternative LED construction is a doped polymer organic light emitting device. Hybrid Ink-jet printing is used to directly deposit patterned luminescent doped-polymer films, for example polyvinylcarbazol (PVK) film, onto electrodes in the manner shown in Fig. 16.
The invention is not limited to the embodiments described but may be varied in construction and detail. For example, conductors other than copper may be used for the interconnects, such as aluminium. Also, the sensor device may be a "stripped down" version of the sensor, a "humidity-to-digital" sensor chip, having no radio or microcontroller or flash memory. In this case, calibration of the A-to-D and sensor is achieved by blowing various poly fuses in the voltage reference circuit and capacitor array. It should be noted that testing need not involve testing every code of the A-to- D, thereby simplifying testing significantly, and reducing cost. Also, some or more of the following features may be provided individually or in combination in a method and device other than as described in the embodiments above: use of strained silicon as a low noise amplifier, low-frequency channel selection/hopping, SAR with replication of the capacitor array, porous silicon LED, audio piezo-electric polymer microphone sensor, audio compression and transmission at low duty cycle, the microcontroller features.

Claims

Claims
1. An integrated sensor device comprising:
MOS circuits in a semiconductor substrate, interconnect levels with intercom ect conductors and insulating dielectric, said levels being over the substrate and interconnecting the MOS circuits, the interconnect levels incorporating a sensor having electrodes embedded in the interconnect dielectric, and the MOS circuits including a processor for processing signals from the sensor electrodes.
2. An integrated sensor device as claimed in claim 1, wherein the sensor comprises a porous oxide for ingress of a gas or humidity being sensed.
3. An integrated sensor device as claimed in claim 2, wherein the porous oxide is carbon-doped SiO2.
4. An integrated sensor device as claimed in any preceding claim, wherein the sensor is a capactive sensor.
5. An integrated sensor device as claimed in claim 4, wherein the sensor comprises a passivation layer over the sensor electrodes.
6. An integrated sensor device as claimed in claim 5, wherein the porous oxide is deposited on the passivation layer, and the MOS circuits detect changes in a fringe field between the electrodes.
7. An integrated sensor device as claimed in claims 5 or 6, comprising etch stop layers between the interconnect levels, and the passivation layer is of the same composition as the etch stop material.
8. An integrated sensor device as claimed in claim 7, wherein the passivation layer is of Si3N composition.
9. An integrated sensor device as claimed in any of claims 5 to 8, wherein the passivation layer is recessed over the sensing electrodes.
10. An integrated sensor device as claimed in claim 9, wherein there is a porous oxide film in the recess.
11. An integrated sensor device as claimed in any of claims 1 to 4, wherein the porous oxide is between the electrodes and is exposed.
12. An integrated sensor device as claimed in any preceding claim, wherein the MOS circuits are directly beneath the sensor in a vertical dimension.
13. An integrated sensor device as claimed in any preceding claim, wherein the MOS circuits include a temperature sensor.
14. An integrated sensor device as claimed in claims 13, wherein the temperature sensor comprises a PNP transistor.
15. An integrated sensor device as claimed in claims 13 or 14, wherein the MOS circuits include a microcontroller for processing both gas or humidity signals from the gas or humidity sensor and temperature signals from the temperature sensor to provide an enhanced output.
16. An integrated sensor device as claimed in claim 15, wherein the enhanced output is temperature-corrected gas or humidity readings.
17. An integrated sensor device as claimed in claim 1, wherein the sensor comprises polyimide deposited over the sensor electrodes.
18. An integrated sensor device as claimed in any preceding claim, wherein the MOS circuits include an A-to-D converter connected between the sensor electrodes and the processor.
19. An integrated sensor device as claimed in claim 18, wherein the A-to-D converter comprises an array of dummy capacitors with a constant topography surrounding active A-to-D converter capacitors.
20. An integrated sensor device as claimed in any preceding claim, further comprising a light emitting diode.
21. An integrated sensor device as claimed in claim 20, wherein said diode is formed in a deep trench to a lower interconnect level laterally of the sensor electrodes.
22. An integrated sensor device as claimed in any preceding claims, wherein the device comprises a photo-detector diode.
23. An integrated sensor device as claimed in claim 22, wherein said diode is in a deep trench in a lower interconnect level laterally of the sensor electrodes.
24. An integrated sensor device as claimed in any preceding claim, wherein the MOS circuits include a wireless transceiver.
25. An integrated sensor device as claimed in claim 24, wherein the wireless transceiver is for communication with other nodes in a network, and it comprises a means for switching channel frequency according to a low frequency channel switching scheme upon detection of interference.
26. An integrated sensor device as claimed in claims 24 or 25, wherein an interconnect level includes a low noise amplifier.
27. An integrated sensor device as claimed in claim 26, wherein the low noise amplifier comprises a strained silicon region beneath a conductor.
28. An integrated sensor device as claimed in claim 27, wherein the strained silicon is in a fifth or sixth interconnect level above the substrate.
29. An integrated sensor device as claimed in any preceding claim, wherein the sensor comprises a detecting element connected between pads on an upper surface of the device.
30. An integrated sensor device as claimed in claim 29, wherein the element is a gas-sensing thin film.
31. An integrated sensor device as claimed in claim 30, wherein the element is of zinc oxide composition.
32. An integrated sensor device as claimed in claim 29, wherein said element detects sound and the MOS circuits comprise an audio processor for processing signals from the elements.
33. A method of producing a sensor device of any preceding claim, the method comprising the steps of: fabricating the MOS circuits in the substrate, fabricating the interconnect levels in successive fabrication cycles according to interconnect design to interconnect the MOS circuits, and fabricating the sensor electrodes and dielectric in a final interconnect level.
34. A method as claimed in claim 33, comprising the further step of depositing a passivation layer over the top interconnect level.
35. A method as claimed in claim 34, comprising the steps of depositing an etch stop layer over each layer of dielectric in the interconnect levels, and depositing etch stop material over the top interconnect level dielectric to provide the passivation layer.
36. A method of any of claims 33 to 35, wherein porous oxide is provided as a dielectric in lower interconnect levels and regular oxide is used as a dielectric in upper interconnect levels.
37. A method of any of claims 33 to 36, wherein a strained low noise amplifier is deposited in an upper interconnect level, said amplifier comprising a strained silicon region.
PCT/IE2005/000033 2004-04-02 2005-03-30 An integrated electronic sensor WO2005095936A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP05718823.7A EP1730506B1 (en) 2004-04-02 2005-03-30 An integrated electronic sensor
JP2007505733A JP2007535662A (en) 2004-04-02 2005-03-30 Integrated electronic sensor

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US55856504P 2004-04-02 2004-04-02
US60/558,565 2004-04-02

Publications (1)

Publication Number Publication Date
WO2005095936A1 true WO2005095936A1 (en) 2005-10-13

Family

ID=34962453

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IE2005/000033 WO2005095936A1 (en) 2004-04-02 2005-03-30 An integrated electronic sensor

Country Status (5)

Country Link
US (7) US7554134B2 (en)
EP (1) EP1730506B1 (en)
JP (1) JP2007535662A (en)
CN (2) CN1961209A (en)
WO (1) WO2005095936A1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007124725A1 (en) * 2006-04-27 2007-11-08 CiS Institut für Mikrosensorik gGmbH Microsensor
WO2008015118A1 (en) * 2006-08-03 2008-02-07 Innovative Sensor Technology Ist Ag Method for determining the relative humidity of a medium and a corresponding apparatus
EP2282333A1 (en) 2009-07-27 2011-02-09 Nxp B.V. Integrated circuit and manufacturing method therefor
EP2508874A1 (en) * 2011-04-08 2012-10-10 Nxp B.V. Capacitive sensor, integrated circuit, electronic device and method
EP2554980A1 (en) * 2011-08-03 2013-02-06 Nxp B.V. Integrated circuit with sensor and method of manufacturing such an integrated circuit
EP2930500A1 (en) * 2014-04-07 2015-10-14 Innochips Technology Co., Ltd. Layered sensor array device
US9263500B2 (en) 2012-03-30 2016-02-16 Ams International Ag Integrated circuit comprising a gas sensor
EP1929285B1 (en) * 2005-09-30 2017-02-22 Silicon Laboratories Inc. An integrated electronic sensor and method for its production

Families Citing this family (78)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1961209A (en) * 2004-04-02 2007-05-09 蒂莫西·卡明斯 Integrated electronic sensor
US8357958B2 (en) * 2004-04-02 2013-01-22 Silicon Laboratories Inc. Integrated CMOS porous sensor
US7948014B2 (en) * 2005-05-26 2011-05-24 Nxp B.V. Electronic device
EP1952134A1 (en) * 2005-11-17 2008-08-06 Koninklijke Philips Electronics N.V. Moisture sensor
US7420365B2 (en) * 2006-03-15 2008-09-02 Honeywell International Inc. Single chip MR sensor integrated with an RF transceiver
US20070235877A1 (en) * 2006-03-31 2007-10-11 Miriam Reshotko Integration scheme for semiconductor photodetectors on an integrated circuit chip
US7700975B2 (en) * 2006-03-31 2010-04-20 Intel Corporation Schottky barrier metal-germanium contact in metal-germanium-metal photodetectors
DE102006037243B4 (en) * 2006-08-09 2010-06-02 Siemens Ag Network for the wireless transmission of data
KR20080041912A (en) * 2006-11-08 2008-05-14 삼성전자주식회사 Pixel circuit of cmos image sensor capable of controlling sensitivity
US8063469B2 (en) * 2008-09-30 2011-11-22 Infineon Technologies Ag On-chip radio frequency shield with interconnect metallization
US8169059B2 (en) * 2008-09-30 2012-05-01 Infineon Technologies Ag On-chip RF shields with through substrate conductors
US8889548B2 (en) 2008-09-30 2014-11-18 Infineon Technologies Ag On-chip RF shields with backside redistribution lines
US7948064B2 (en) 2008-09-30 2011-05-24 Infineon Technologies Ag System on a chip with on-chip RF shield
US8178953B2 (en) 2008-09-30 2012-05-15 Infineon Technologies Ag On-chip RF shields with front side redistribution lines
US8124953B2 (en) 2009-03-12 2012-02-28 Infineon Technologies Ag Sensor device having a porous structure element
CN101738422B (en) 2009-12-23 2012-09-05 北京宝力马传感技术有限公司 Humidity measuring device and method
KR101665669B1 (en) * 2010-03-04 2016-10-13 삼성전자주식회사 Semiconductor devices and methods of forming the same
US8927909B2 (en) * 2010-10-11 2015-01-06 Stmicroelectronics, Inc. Closed loop temperature controlled circuit to improve device stability
EP2508881B1 (en) * 2011-04-04 2019-01-23 Sensirion AG Testing a humidity sensor
US9164052B1 (en) 2011-09-30 2015-10-20 Silicon Laboratories Inc. Integrated gas sensor
US8852513B1 (en) 2011-09-30 2014-10-07 Silicon Laboratories Inc. Systems and methods for packaging integrated circuit gas sensor systems
US8669131B1 (en) 2011-09-30 2014-03-11 Silicon Laboratories Inc. Methods and materials for forming gas sensor structures
US8691609B1 (en) 2011-09-30 2014-04-08 Silicon Laboratories Inc. Gas sensor materials and methods for preparation thereof
EP2623969B1 (en) * 2012-01-31 2014-05-14 Nxp B.V. Integrated circuit and manufacturing method
KR101874839B1 (en) * 2012-04-25 2018-07-05 이플러스이엘렉트로닉 게엠베하 Apparatus for humidity sensor
CN102721429B (en) * 2012-06-21 2015-06-24 昆山诺科传感器集成有限公司 Frequency-output temperature and humidity transmitter
EP2677307B1 (en) 2012-06-21 2016-05-11 Nxp B.V. Integrated circuit with sensors and manufacturing method
US9287219B2 (en) 2012-07-25 2016-03-15 Silicon Laboratories Inc. Radiation-blocking structures
EP2720034B1 (en) * 2012-10-12 2016-04-27 ams International AG Integrated Circuit comprising a relative humidity sensor and a thermal conductivity based gas sensor
CN103115569B (en) * 2012-10-22 2016-05-04 深圳市嘉瀚科技有限公司 There is the Monobloc photoelectric sensor of wireless transmission function
EP2762865A1 (en) * 2013-01-31 2014-08-06 Sensirion Holding AG Chemical sensor and method for manufacturing such a chemical sensor
US10175188B2 (en) * 2013-03-15 2019-01-08 Robert Bosch Gmbh Trench based capacitive humidity sensor
JP6286845B2 (en) * 2013-03-22 2018-03-07 富士通株式会社 Thermoelectric element mounting module and manufacturing method thereof
US9234859B2 (en) * 2013-03-28 2016-01-12 Stmicroelectronics S.R.L. Integrated device of a capacitive type for detecting humidity, in particular manufactured using a CMOS technology
US10323980B2 (en) * 2013-03-29 2019-06-18 Rensselaer Polytechnic Institute Tunable photocapacitive optical radiation sensor enabled radio transmitter and applications thereof
EP2793018A1 (en) * 2013-04-19 2014-10-22 Nxp B.V. Thermal conductivity based gas sensor
CN103209002B (en) * 2013-04-23 2015-12-23 中国科学院深圳先进技术研究院 For the data transmission device of micro wireless sensor node
CA2912616A1 (en) 2013-05-17 2014-11-20 fybr Distributed remote sensing system gateway
US9652987B2 (en) * 2013-05-17 2017-05-16 fybr Distributed remote sensing system component interface
CN104981688B (en) * 2013-05-29 2018-07-13 罗斯蒙特分析公司 Stink damp bulk detector with humidity and temperature-compensating
US10177781B2 (en) * 2013-06-24 2019-01-08 Silicon Laboratories Inc. Circuit including a switched capacitor bridge and method
US10160966B2 (en) 2013-12-12 2018-12-25 Altratech Limited Sample preparation method and apparatus
US10746683B2 (en) 2013-12-12 2020-08-18 Altratech Limited Capacitive sensor and method of use
TWI523808B (en) * 2014-01-29 2016-03-01 先技股份有限公司 Mems gas sensing device
KR102238937B1 (en) * 2014-07-22 2021-04-09 주식회사 키 파운드리 A Humidity Sensor formed by void within Interconnect and method of manufacturing the same
EP3037810B1 (en) * 2014-12-23 2017-10-25 EM Microelectronic-Marin SA Improved moisture sensor
CN104614294A (en) * 2014-12-31 2015-05-13 北京工业大学 Hierarchical heterogeneous air quality real-time monitoring model based on Zigbee wireless communication technique
CN104627947B (en) * 2015-02-09 2016-02-10 江西师范大学 Cmos humidity sensor and forming method thereof
EP3062097A1 (en) * 2015-02-27 2016-08-31 EM Microelectronic-Marin SA Moisture sensor with thermal module
US10909607B2 (en) 2015-06-05 2021-02-02 Boveda Inc. Systems, methods and devices for controlling humidity in a closed environment with automatic and predictive identification, purchase and replacement of optimal humidity controller
US10055781B2 (en) 2015-06-05 2018-08-21 Boveda Inc. Systems, methods and devices for controlling humidity in a closed environment with automatic and predictive identification, purchase and replacement of optimal humidity controller
US9891183B2 (en) * 2015-07-07 2018-02-13 Nxp B.V. Breach sensor
US10670554B2 (en) 2015-07-13 2020-06-02 International Business Machines Corporation Reconfigurable gas sensor architecture with a high sensitivity at low temperatures
EP3163295B1 (en) * 2015-11-02 2020-09-30 Alpha M.O.S. System and method for characterizing a gas sample
CN105675051B (en) * 2016-01-12 2018-06-05 上海申矽凌微电子科技有限公司 The integrated circuit for manufacturing the method for sensor IC and being manufactured using this method
KR20180105198A (en) * 2016-01-27 2018-09-27 더 제너럴 하스피탈 코포레이션 Magnetic electrochemical detection
US10336606B2 (en) * 2016-02-25 2019-07-02 Nxp Usa, Inc. Integrated capacitive humidity sensor
US20170287757A1 (en) * 2016-03-30 2017-10-05 Robert F. Kwasnick Damage monitor
CN105742247B (en) * 2016-04-07 2019-07-26 上海申矽凌微电子科技有限公司 The manufacturing method of sensor IC and the integrated circuit manufactured using this method
US10083883B2 (en) * 2016-06-20 2018-09-25 Applied Materials, Inc. Wafer processing equipment having capacitive micro sensors
CN106124576B (en) * 2016-06-28 2018-12-18 上海申矽凌微电子科技有限公司 Integrated humidity sensor and multiple-unit gas sensor and its manufacturing method
CN106082102B (en) * 2016-07-12 2017-12-15 上海申矽凌微电子科技有限公司 The sensor circuit manufacture method and sensor of integrated temperature humidity gas sensing
US10429330B2 (en) * 2016-07-18 2019-10-01 Stmicroelectronics Pte Ltd Gas analyzer that detects gases, humidity, and temperature
US10254261B2 (en) 2016-07-18 2019-04-09 Stmicroelectronics Pte Ltd Integrated air quality sensor that detects multiple gas species
CN106249093A (en) * 2016-07-22 2016-12-21 上海新时达电气股份有限公司 Automatically differentiate and detect the devices and methods therefor of pre-buried sensor in electrical equipment
US10557812B2 (en) 2016-12-01 2020-02-11 Stmicroelectronics Pte Ltd Gas sensors
US10480495B2 (en) * 2017-05-08 2019-11-19 Emerson Climate Technologies, Inc. Compressor with flooded start control
EP4219751A1 (en) 2017-09-20 2023-08-02 Altratech Limited Diagnostic device and system
US10453791B2 (en) * 2018-02-06 2019-10-22 Apple Inc. Metal-on-metal capacitors
CN108562697A (en) * 2018-03-30 2018-09-21 歌尔股份有限公司 A kind of indoor harmful gas monitoring device
US10804195B2 (en) * 2018-08-08 2020-10-13 Qualcomm Incorporated High density embedded interconnects in substrate
JP7167396B2 (en) * 2018-11-16 2022-11-09 ミネベアミツミ株式会社 Humidity detector and failure determination method
CN209326840U (en) 2018-12-27 2019-08-30 热敏碟公司 Pressure sensor and pressure transmitter
CN111696952A (en) * 2019-03-13 2020-09-22 住友电工光电子器件创新株式会社 Microwave integrated circuit
US11397047B2 (en) * 2019-04-10 2022-07-26 Minebea Mitsumi Inc. Moisture detector, moisture detection method, electronic device, and log output system
KR20220023074A (en) * 2020-08-20 2022-03-02 삼성전자주식회사 Semiconductor package test device and method for the same
US11855019B2 (en) 2021-02-11 2023-12-26 Globalfoundries Singapore Pte. Ltd. Method of forming a sensor device
CN113252734B (en) * 2021-06-22 2021-09-24 电子科技大学 Resistance type gas sensor flexible circuit and gas concentration calculation method

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63103957A (en) * 1986-10-20 1988-05-09 Seiko Epson Corp Humidity detector
US5801428A (en) * 1996-06-12 1998-09-01 Siemens Aktiengesellschaft MOS transistor for biotechnical applications
US6017775A (en) * 1996-10-10 2000-01-25 Micronas Intermetall Gmbh Process for manufacturing a sensor with a metal electrode in a metal oxide semiconductor (MOS) structure
US6111280A (en) * 1997-01-15 2000-08-29 University Of Warwick Gas-sensing semiconductor devices
US20040008471A1 (en) * 2002-07-09 2004-01-15 Davis Richard A. Relative humidity sensor with integrated signal conditioning
US6690569B1 (en) * 1999-12-08 2004-02-10 Sensirion A/G Capacitive sensor

Family Cites Families (49)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4057823A (en) * 1976-07-02 1977-11-08 International Business Machines Corporation Porous silicon dioxide moisture sensor and method for manufacture of a moisture sensor
GB1586117A (en) * 1977-06-22 1981-03-18 Rosemount Eng Co Ltd Solid state sensor element
US4165642A (en) * 1978-03-22 1979-08-28 Lipp Robert J Monolithic CMOS digital temperature measurement circuit
US4419021A (en) * 1980-02-04 1983-12-06 Matsushita Electric Industrial Co., Ltd. Multi-functional sensing or measuring system
JPS58111747A (en) 1981-12-25 1983-07-02 Yamatake Honeywell Co Ltd Gas sensor and manufacture thereof
CA1216330A (en) * 1983-02-07 1987-01-06 Junji Manaka Low power gas detector
US4656463A (en) * 1983-04-21 1987-04-07 Intelli-Tech Corporation LIMIS systems, devices and methods
US4542640A (en) * 1983-09-15 1985-09-24 Clifford Paul K Selective gas detection and measurement system
JPS6066145A (en) * 1983-09-20 1985-04-16 Omron Tateisi Electronics Co External atmosphere detecting device
JPS60242354A (en) * 1984-05-16 1985-12-02 Sharp Corp Fet type sensor
JPS6157847A (en) * 1984-08-29 1986-03-24 Sharp Corp Field effect type humidity sensor
US4931381A (en) * 1985-08-12 1990-06-05 Hoechst Celanese Corporation Image reversal negative working O-quinone diazide and cross-linking compound containing photoresist process with thermal curing treatment
GB8606045D0 (en) * 1986-03-12 1986-04-16 Emi Plc Thorn Gas sensitive device
JPH06105232B2 (en) * 1986-07-17 1994-12-21 株式会社東芝 Insulation gate electric field effect type moisture sensitive element
US4793181A (en) * 1987-06-02 1988-12-27 Djorup Robert Sonny Constant temperature sorption hygrometer
US4831381A (en) * 1987-08-11 1989-05-16 Texas Instruments Incorporated Charge redistribution A/D converter with reduced small signal error
JPH01196558A (en) * 1988-02-01 1989-08-08 Takara Kogyo Kk Humidity sensor
US4876890A (en) * 1988-06-29 1989-10-31 Uop Moisture sensing apparatus and method
JPH02232901A (en) * 1989-03-07 1990-09-14 Seiko Epson Corp Humidity sensor
US5120421A (en) * 1990-08-31 1992-06-09 The United States Of America As Represented By The United States Department Of Energy Electrochemical sensor/detector system and method
JP3041491B2 (en) 1991-06-06 2000-05-15 株式会社トーキン Humidity sensor
CA2066929C (en) * 1991-08-09 1996-10-01 Katsuji Kimura Temperature sensor circuit and constant-current circuit
US5481129A (en) * 1991-10-30 1996-01-02 Harris Corporation Analog-to-digital converter
US6399970B2 (en) * 1996-09-17 2002-06-04 Matsushita Electric Industrial Co., Ltd. FET having a Si/SiGeC heterojunction channel
US5878332A (en) * 1997-02-07 1999-03-02 Eic Enterprises Corporation Multiple frequency RF transceiver
EP0882978A1 (en) * 1997-06-04 1998-12-09 STMicroelectronics S.r.l. Integrated semi-conductor device comprising a chemoresistive gas microsensor and manufacturing process thereof
DE69726718T2 (en) * 1997-07-31 2004-10-07 St Microelectronics Srl Method of manufacturing highly sensitive integrated acceleration and gyroscopic sensors and sensors manufactured in this way
JP3514361B2 (en) * 1998-02-27 2004-03-31 Tdk株式会社 Chip element and method of manufacturing chip element
US6288442B1 (en) * 1998-09-10 2001-09-11 Micron Technology, Inc. Integrated circuit with oxidation-resistant polymeric layer
JP2000299438A (en) * 1999-04-15 2000-10-24 Hitachi Ltd Semiconductor integrated circuit
DE19924906C2 (en) * 1999-05-31 2001-05-31 Daimler Chrysler Ag Semiconductor gas sensor, gas sensor system and method for gas analysis
US6673644B2 (en) * 2001-03-29 2004-01-06 Georgia Tech Research Corporation Porous gas sensors and method of preparation thereof
US6580600B2 (en) * 2001-02-20 2003-06-17 Nippon Soken, Inc. Capacitance type humidity sensor and manufacturing method of the same
US6632478B2 (en) * 2001-02-22 2003-10-14 Applied Materials, Inc. Process for forming a low dielectric constant carbon-containing film
US6484559B2 (en) * 2001-02-26 2002-11-26 Lucent Technologies Inc. Odor sensing with organic transistors
US6348407B1 (en) * 2001-03-15 2002-02-19 Chartered Semiconductor Manufacturing Inc. Method to improve adhesion of organic dielectrics in dual damascene interconnects
US20030010988A1 (en) * 2001-07-11 2003-01-16 Motorola, Inc. Structure and method for fabricating semiconductor structures with integrated optical components and controller
JP4501320B2 (en) * 2001-07-16 2010-07-14 株式会社デンソー Capacitive humidity sensor
AU2002341803A1 (en) * 2001-09-24 2003-04-07 Amberwave Systems Corporation Rf circuits including transistors having strained material layers
US6673664B2 (en) * 2001-10-16 2004-01-06 Sharp Laboratories Of America, Inc. Method of making a self-aligned ferroelectric memory transistor
JP3869815B2 (en) * 2003-03-31 2007-01-17 Necエレクトロニクス株式会社 Semiconductor integrated circuit device
US7053425B2 (en) * 2003-11-12 2006-05-30 General Electric Company Gas sensor device
JP4065855B2 (en) * 2004-01-21 2008-03-26 株式会社日立製作所 Biological and chemical sample inspection equipment
JP3994975B2 (en) * 2004-02-27 2007-10-24 株式会社デンソー Capacitive humidity sensor
JP4553611B2 (en) * 2004-03-15 2010-09-29 三洋電機株式会社 Circuit equipment
CN1961209A (en) 2004-04-02 2007-05-09 蒂莫西·卡明斯 Integrated electronic sensor
US7096716B2 (en) * 2004-11-03 2006-08-29 Avago Technologies Ecbu Ip (Singapore) Pte. Ltd. Integration of thermal regulation and electronic fluid sensing
EP1767934B1 (en) * 2005-09-21 2007-12-05 Adixen Sensistor AB Hydrogen gas sensitive semiconductor sensor
EP1929285B1 (en) * 2005-09-30 2017-02-22 Silicon Laboratories Inc. An integrated electronic sensor and method for its production

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63103957A (en) * 1986-10-20 1988-05-09 Seiko Epson Corp Humidity detector
US5801428A (en) * 1996-06-12 1998-09-01 Siemens Aktiengesellschaft MOS transistor for biotechnical applications
US6017775A (en) * 1996-10-10 2000-01-25 Micronas Intermetall Gmbh Process for manufacturing a sensor with a metal electrode in a metal oxide semiconductor (MOS) structure
US6111280A (en) * 1997-01-15 2000-08-29 University Of Warwick Gas-sensing semiconductor devices
US6690569B1 (en) * 1999-12-08 2004-02-10 Sensirion A/G Capacitive sensor
US20040008471A1 (en) * 2002-07-09 2004-01-15 Davis Richard A. Relative humidity sensor with integrated signal conditioning

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
BALTES H ET AL: "MICROMACHINED THERMALLY BASED CMOS MICROSENSORS", PROCEEDINGS OF THE IEEE, IEEE. NEW YORK, US, vol. 86, no. 8, August 1998 (1998-08-01), pages 1660 - 1678, XP000848432, ISSN: 0018-9219 *
BALTES H ET AL: "THE ELECTRONIC NOSE IN LILLIPUT", IEEE SPECTRUM, IEEE INC. NEW YORK, US, vol. 35, no. 9, September 1998 (1998-09-01), pages 35 - 38, XP000848942, ISSN: 0018-9235 *
BOUSSE L ET AL: "A PROCESS FOR THE COMBINED FABRICATION OF ION SENSORS AND CMOS CIRCUITS", IEEE ELECTRON DEVICE LETTERS, IEEE INC. NEW YORK, US, vol. 9, no. 1, January 1988 (1988-01-01), pages 44 - 46, XP001008777, ISSN: 0741-3106 *
LEMME H: "CMOS-SENSOREN GEHOERT DIE ZUKUNFT", ELEKTRONIK, WEKA FACHZEITSCR.-VERLAG, MUNCHEN, DE, vol. 43, no. 24, 29 November 1994 (1994-11-29), pages 57 - 66, XP000490330, ISSN: 0013-5658 *
PATENT ABSTRACTS OF JAPAN vol. 012, no. 350 (P - 760) 20 September 1988 (1988-09-20) *

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1929285B1 (en) * 2005-09-30 2017-02-22 Silicon Laboratories Inc. An integrated electronic sensor and method for its production
WO2007124725A1 (en) * 2006-04-27 2007-11-08 CiS Institut für Mikrosensorik gGmbH Microsensor
WO2008015118A1 (en) * 2006-08-03 2008-02-07 Innovative Sensor Technology Ist Ag Method for determining the relative humidity of a medium and a corresponding apparatus
EP2282333A1 (en) 2009-07-27 2011-02-09 Nxp B.V. Integrated circuit and manufacturing method therefor
US8779548B2 (en) 2009-07-27 2014-07-15 Nxp, B.V. Integrated circuit including a porous material for retaining a liquid and manufacturing method thereof
US8779781B2 (en) 2011-04-08 2014-07-15 Nxp, B.V. Capacitive sensor, integrated circuit, electronic device and method
EP2508874A1 (en) * 2011-04-08 2012-10-10 Nxp B.V. Capacitive sensor, integrated circuit, electronic device and method
CN102735716A (en) * 2011-04-08 2012-10-17 Nxp股份有限公司 Capacitive sensor, integrated circuit, electronic device and method
EP2554981A1 (en) * 2011-08-03 2013-02-06 Nxp B.V. Integrated circuit with a gas sensor and method of manufacturing such an integrated circuit
US8853798B2 (en) 2011-08-03 2014-10-07 Nxp, B.V. Integrated circuit with sensor and method of manufacturing such an integrated circuit
EP2554980A1 (en) * 2011-08-03 2013-02-06 Nxp B.V. Integrated circuit with sensor and method of manufacturing such an integrated circuit
US10197520B2 (en) 2011-08-03 2019-02-05 Ams International Ag Integrated circuit with sensor and method of manufacturing such an integrated circuit
US9263500B2 (en) 2012-03-30 2016-02-16 Ams International Ag Integrated circuit comprising a gas sensor
US9865647B2 (en) 2012-03-30 2018-01-09 Ams International Ag Integrated circuit comprising a gas sensor
EP2930500A1 (en) * 2014-04-07 2015-10-14 Innochips Technology Co., Ltd. Layered sensor array device

Also Published As

Publication number Publication date
US20120256236A1 (en) 2012-10-11
US20150316498A1 (en) 2015-11-05
US20110089472A1 (en) 2011-04-21
US8497531B2 (en) 2013-07-30
US8507955B2 (en) 2013-08-13
US20110089439A1 (en) 2011-04-21
CN1961209A (en) 2007-05-09
US20090273009A1 (en) 2009-11-05
US20110098937A1 (en) 2011-04-28
US8507954B2 (en) 2013-08-13
US8648395B2 (en) 2014-02-11
EP1730506A1 (en) 2006-12-13
US7554134B2 (en) 2009-06-30
JP2007535662A (en) 2007-12-06
US20050218465A1 (en) 2005-10-06
CN102854229A (en) 2013-01-02
EP1730506B1 (en) 2018-09-26

Similar Documents

Publication Publication Date Title
US8507955B2 (en) Sensor device having MOS circuits, a gas or humidity sensor and a temperature sensor
EP1929285B1 (en) An integrated electronic sensor and method for its production
US8357958B2 (en) Integrated CMOS porous sensor
US20150338360A1 (en) Integrated CMOS Porous Sensor
US6580600B2 (en) Capacitance type humidity sensor and manufacturing method of the same
EP2554980B1 (en) Integrated circuit with sensor and method of manufacturing such an integrated circuit
US20030039586A1 (en) Membrane type gas sensor and method for manufacturing membrane type gas sensor
JP2007535662A5 (en)
WO2012152308A1 (en) Ion sensitive field effect transistor
WO2007122287A1 (en) Micro hotplate semiconductive gas sensor
US7355200B2 (en) Ion-sensitive field effect transistor and method for producing an ion-sensitive field effect transistor
US20020114125A1 (en) Capacitance type humidity sensor and manufacturing method of the same
US20030037590A1 (en) Method of self-testing a semiconductor chemical gas sensor including an embedded temperature sensor
US7390682B2 (en) Method for testing metal-insulator-metal capacitor structures under high temperature at wafer level
IES20050180A2 (en) An integrated electronic sensor
IE84228B1 (en) An integrated electronic sensor
IE20050180U1 (en) An integrated electronic sensor
IES84059Y1 (en) An integrated electronic sensor
IE84764B1 (en) An integrated electronic sensor
Stoev et al. An integrated gas sensor on silicon substrate with sensitive SnOx layer
US20200333284A1 (en) High surface area electrode for electrochemical sensor
JPS6258456B2 (en)

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2007505733

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2005718823

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Country of ref document: DE

WWE Wipo information: entry into national phase

Ref document number: 200580017844.6

Country of ref document: CN

WWP Wipo information: published in national office

Ref document number: 2005718823

Country of ref document: EP