DE102008030750A1 - Radiation detector, has passive area formed along side surfaces for controlling addition of radiations irradiated laterally in direction of active area for producing signal of radiation detector in active area of semiconductor body - Google Patents

Abstract

The detector (1) has a semiconductor body (2) with an active area (20) made of silicon for detecting radiations and side surfaces (23) for limiting the body in a lateral direction. A passive area (6) made of semiconductor material is formed along the side surfaces for controlling addition of the radiations irradiated laterally in the direction of the active area for producing a signal of the detector in the active area. The passive area runs between the active area and the side surfaces and is formed by a recess in the body, where the recess is filled with a filling material.

Description

The The present application relates to a radiation detector.

typical Silicon photodiodes exhibit a comparatively broadband spectral Sensitivity of about 200 nm to 1150 nm, the spectral Sensitivity maximum in the near infrared at wavelengths between 750 nm and 900 nm. Especially because of this high sensitivity in the near infrared shows the spectral sensitivity distribution These diodes vary greatly from the sensitivity of the human Eye, which has a maximum at about 550 nm.

It It is an object to provide a radiation detector whose spectral Sensitivity distribution to a given sensitivity distribution, in particular to the sensitivity distribution of the human Eye, adjusted.

These Task is solved by a radiation detector according to claim 1. Further embodiments and further developments are the subject of the dependent claims.

According to one embodiment For example, a radiation detector comprises a semiconductor body, one for detection radiation provided active area, a radiation entrance surface and one the semiconductor body has laterally limiting side surface. Along the side surface is at least partially formed a passive area, at least partially prevents radiation that is lateral in the direction of the active Area irradiates, to generate a signal of the radiation detector contributes in the active area.

through the passive area can be the proportion of radiation that comes from the side Direction in the active area and there, such as by generation and spatial Separation of electron-hole pairs, can lead to a signal contribution, repressed or at least greatly reduced. This side towards The radiation irradiated in the active region could amplify in the active region Cause signal component, one of a given sensitivity distribution cause a different sensitivity distribution of the radiation detector could. In other words, the proportion of the signal of the radiation detector for the one Radiation maximized by the radiation entrance surface in the active area is coupled.

The Spectral sensitivity distribution of the radiation detector is so simplified to a given sensitivity distribution, preferably the sensitivity distribution of the human eye, adaptable.

Under an active area is understood to mean, in particular, an area in the absorption of radiation to one at the radiation detector externally tapped signal leads. The signal generation can, for example, by the generation of Electron-hole pairs are due to absorption of radiation, where the electrons and holes, in a space-charge zone, for example, and so on lead to an externally detectable signal.

in the Difference is under a passive area an area understood, in which the incident on this radiation no or at least no significant contribution to the signal of the radiation detector supplies. For example, the passive area can be designed in such a way the radiation is absorbed and / or absorbed in the passive region the passive area is reflected. Unlike the active one Range is the passive range expediently carried out such that Absorption of radiation in the passive range to none or at least no significant externally tapped signal leads.

In In a preferred embodiment, the passive region extends between the active region and the side surface of the semiconductor body. So can be reduced, the radiation component, the side in the Semiconductor body radiates in and contributes to the signal generation in the active area. The Coupling of the radiation, which generates a signal in the active area causes, thus takes place substantially over the radiation entrance surface of the The semiconductor body.

Especially the radiation can be blocked by means of the passive region, this means, it can be at least partially prevented that einstrahlende side Radiation enters the active area. So this radiation can be blocked before this in the active area to a signal component to lead can, which deviates from the given sensitivity distribution Could cause sensitivity distribution.

In In a preferred embodiment, the passive area circulates around the active region in a plan view of the semiconductor body laterally. In particular, the passive region can completely lateralize the active region circulate. The signal component of the radiation detector due to radiation incident on the radiation detector laterally can be reduced as much as possible.

in the Doubt will be under a lateral direction in the context of the application especially understood a direction that in a main extension plane of the semiconductor body runs.

The Radiation entrance area preferably extends parallel to the main extension plane of the The semiconductor body.

In one embodiment variant, the passive region is formed by means of a recess in the semiconductor body. The recess may be filled with a filling material which absorbs or reflects the incident radiation. In particular, a material which has a large absorption coefficient at wavelengths in the near infrared, in particular between 700 nm and 1050 nm, is suitable as absorbent filling material. For example, the filler material polycrystalline silicon, in particular strongly doped polycrystalline silicon, for instance with a doping concentration of at least 1 x 10 ¹⁸ cm ^-3, or consist thereof. As a reflective material is particularly suitable a metal, such as Au, Al, Cu or W.

In vertical direction, ie in a direction perpendicular to the main extension plane the semiconductor body, The recess preferably extends at least starting from the radiation entrance surface to the active area. The lateral coupling of radiation in the active area can be thus reduced in an efficient way.

In A further embodiment variant is the passive area by means of a semiconductor material is formed which is more heavily doped than the semiconductor material of the active area. In particular, the semiconductor material can be at least Be doped 100 times as strong as the semiconductor material of the active Range. The higher the doping of the semiconductor material is the higher the recombination rates for electron-hole pairs, which are generated by absorption of radiation. That is, the Recombination probability for electron-hole pairs is like this high, that these recombine before the charge carriers are spatially separated from each other be disconnected and to an external contact of the radiation detector can reach.

In A further embodiment variant is the passive area by means of a diode structure formed. The diode structure is in this case executed that produced in the diode structure by absorption of radiation charge carrier no or no significant contribution to the radiation detector signal deliver.

Especially the diode structure can be short-circuited. For example, can a transition between a p-type and an n-type region of the diode structure short-circuited by means of a connection layer arranged on the semiconductor body be.

at a transition, extending to the side surface of the semiconductor body extends, can leakage currents on the side surface already a sufficiently low-resistance electrical connection between the p-type and the n-type Effect area. These leakage currents can for example due to damage the crystal structure may be caused in forming the side surface. On a additional connection layer outside of the semiconductor body can therefore, especially with a transition exposed on the side surface, also be waived.

In a preferred embodiment is on the radiation entrance surface of the Semiconductor body one Filter structure formed. In particular, the filter structure directly adjacent to the semiconductor body. A separate, from the semiconductor body spaced filter to adjust the spectral sensitivity distribution the radiation detector is thus not required, if necessary but in addition be provided.

The Filter structure, for example, by means of one or more dielectric Be formed layers. For example, the filter structure as a bandpass filter be, the radiation by a radiation detector predetermined maximum of Sensitivity distribution lets through and at least partially prevents radiation outside of the area to be detected hits the active area. Especially in combination with the passive area, the side impacting Radiation blocks, so can be achieved that almost the entire Radiation, which contributes to the signal generation, by arranged on the radiation entrance surface Filter structure passes through.

In Another preferred embodiment is the active area limited in the vertical direction such that a long-wave edge the spectral sensitivity distribution of the active region to the the radiation detector predetermined spectral sensitivity distribution is adjusted. In silicon, for example, has infrared radiation a greater penetration depth on as radiation in the visible spectral range. Therefore, the by infrared radiation caused signal component with reduced Decrease the thickness of the active area.

In other words, due to the limitation of the active region in the vertical direction in the active region, predominantly radiation is absorbed which has only a comparatively small penetration depth, which is thus already absorbed with a high probability even with a comparatively small thickness of the active region. By contrast, long-wave radiation, in particular near-infrared radiation, for example between 700 nm and 1100 nm, is predominantly absorbed in regions of the semiconductor body which are further away from the radiation entrance surface due to the higher penetration depth. By the vertical boundary of the active area can thus be reduced, the proportion of contributing to the signal near infrared radiation.

Farther Preferably, the semiconductor body is such executed that the active area in the vertical direction to a thickness of at the most 10 μm limited is. Across from an active area of greater thickness So can the sensitivity of the active wavelength range of greater than 700 nm can be reduced in a simple manner.

In a design variant is the active area on the Radiation entrance area of the semiconductor body opposite side in the vertical direction by means of an insulating Layer limited. For example, the semiconductor body by means of a composite substrate, wherein a thin wear layer spaced apart from a substrate body by means of an insulating layer is. Such a substrate may be exemplified as an SOI (Silicon on insulator) substrate or as an SOS (Silicon on Sapphire) substrate accomplished be. The space charge zone of the active region may be in the wear layer be educated.

By the insulating layer, the substrate body electrically from the active region be separated, so that in the substrate body by absorption of the radiation generated charge carriers can not get into the active area and thus no significant Contribute to the signal. The active area can thus be limited to the wear layer.

In In a further embodiment variant, the semiconductor body has a cavity on, which faces away from the active area on the radiation entrance surface Limited page. The cavity may for example be filled with a gas, such as air, or evacuated executed be.

In Another embodiment variant is the active area by means of a semiconductor layer is formed which has a thickness of between 1 μm and 8 μm inclusive, preferably between inclusive 2 μm and including 5 microns, has. Farther For example, the semiconductor layer of the active region on the radiation entrance side side facing away from a heavily doped semiconductor layer.

Under a heavily doped semiconductor layer is a semiconductor layer with a doping concentration of at least 1 · 10 ¹⁸ cm ^-3 is meant in particular.

by virtue of the high doping of the heavily doped semiconductor layer is the Recombination probability for generated in this layer Electron-hole pairs increased in such a way that they recombine with a high probability before the charge carriers reach the active area. In the heavily doped semiconductor layer generated charge carriers thus provide no or at least no significant contribution to the signal of the active area.

In a further embodiment variant is on the radiation entrance side opposite side of the active region formed a further diode structure. As described in connection with the diode structure causes In the other diode structure absorbed radiation no signal or at least no significant contribution to the signal of the radiation detector. The further diode structure can continue as in connection with the diode structure described be electrically shorted.

Of the Semiconductor body, in particular the active region, preferably contains silicon. Silicon draws by a good Mikrostrukturierbarkeit, such as by means of photolithographic Techniques in connection with etching processes, off and is still large area and economical available.

Of the active region of the radiation detector can, for example, according to a Photodiode, a phototransistor or a photo Darlington circuit be formed. In a Photo Darlington circuit are two transistors electrically connected in series, wherein the first transistor as a Phototransistor executed is and the signal of the first transistor from the second transistor reinforced becomes.

Farther For example, the radiation detector may be part of an integrated circuit.

Farther Preferably, the radiation detector is designed such that a spectral sensitivity distribution of the radiation detector adapted to that of the human eye. The sensitivity maximum of the radiation detector is preferably between 500 inclusive nm and inclusive 600 nm, more preferably between 530 nm and 570 nm inclusive, approximately 550 nm. The relative sensitivity to the signal at Sensitivity maximum, at about 550 nm, is still preferably below a wavelength of 400 nm and above a wavelength of 700 nm, preferably at most 10%, more preferably at most 5 Further features, configurations and expediencies arise the following description of the embodiments in conjunction with the figures.

It demonstrate:

the 1A and 1B a first embodiment of a radiation detector in cal matic supervision ( 1B ) and associated sectional view ( 1A );

2A a result of a simulation of the normalized responsiveness R _N for a radiation detector according to the first embodiment as a function of the wavelength λ of the incident radiation compared to the spectral sensitivity distribution of the human eye (V _λ curve);

2 B a measurement of the responsiveness R of a conventional silicon photodiode as a function of the wavelength λ of the incident radiation;

3 a second embodiment of a radiation detector in a schematic sectional view;

4 a third embodiment of a radiation detector in a schematic sectional view;

5 a fourth embodiment of a radiation detector in a schematic sectional view;

6 a fifth embodiment of a radiation detector in a schematic sectional view;

7 a sixth embodiment of a radiation detector in a schematic sectional view.

Same, similar or equivalent elements are in the figures with provided the same reference numerals.

The Figures are schematic representations and therefore not absolutely true to scale. Rather, you can comparatively small elements and in particular layer thicknesses exaggerated for clarity shown big. be.

A first embodiment of a radiation detector 1 is in 1B shown in a schematic plan. 1A shows the associated sectional view along the line AA '.

The radiation detector 1 has a semiconductor body 2 with a radiation entrance surface 10 and a side surface 23 on. The side surface bounds the semiconductor body 2 in lateral direction. The semiconductor body 2 has an active area provided for the detection of radiation 20 on. The active area 20 is between a first semiconductor region 21 and a second semiconductor region 22 educated. The first semiconductor region and the second semiconductor region are different from each other in conductivity type and may be heavily doped. For example, the first semiconductor region 21 n-type doped and the second semiconductor region 22 be doped p-type or vice versa.

The first semiconductor area 21 and the second semiconductor region 22 are having a first contact 51 or a second contact 52 electrically connected. The contacts 51 . 52 are for external electrical contacting of the radiation detector 1 intended. On during operation of the radiation detector in the active area 20 generated signal, such as a photovoltage or a photocurrent, can at the contacts 51 . 52 be tapped.

Furthermore, the radiation detector 1 a passive area 6 on. By means of the passive area 6 is at least partially prevented by the side surface 23 of the semiconductor body in this coupled radiation in the active region 20 leads to a signal contribution. In the embodiment shown, the passive region is by means of a heavily doped semiconductor region 61 educated. The passive area 6 is thus in the semiconductor body 2 formed and extends between the side surface and the active area 20 , As 1B shows, the passive area rotates 6 the active area 20 in a plan on the radiation detector completely.

The passive area 6 is preferably in the vertical direction from the radiation entrance surface 10 of the semiconductor body to the further semiconductor region 21 , An absorption of radiation passing through the side surface 23 in the semiconductor body 2 coupled can be so efficiently avoided.

The one related to the 1A and 1B described radiation detector according to the first embodiment is exemplified as a silicon photodetector, which is provided as an ambient light sensor. In this case, the given spectral sensitivity distribution is the sensitivity distribution of the human eye.

In the embodiment shown, the first semiconductor region 21 by means of a substrate 26 educated. The substrate 26 can emerge in the manufacture of the radiation detector by singulation, such as by sawing, cutting, splitting or breaking from a silicon wafer. That on the substrate 26 arranged semiconductor material, which is the active region 20 and the second semiconductor region 22 is preferably epitaxially, for example by means of gas phase epitaxy deposited on the substrate.

On the radiation entrance surface 10 is a filter structure 4 educated.

The filter structure 4 For example, it may be implemented as a dielectric filter structure formed by one or more dielectric layers.

The dielectric layers can For example, an oxide, such as silica or titanium oxide, a nitride, such as silicon nitride, or an oxynitride such as silicon oxynitride, contain or consist of such a material.

Deviating from the filter structure 4 For example, be formed by means of a photoresist having suitable optical transmission properties. The filter structure 4 is preferably designed to be a bandpass filter. In particular, the filter structure can be provided to adjust the slope of the edges of the spectral sensitivity of the radiation detector.

Of the Bandpass filter, for example, be designed so that radiation in a wavelength range between 400 nm and 700 nm is transmitted.

Furthermore, the radiation detector 1 executed in the vertical direction such that long-wave radiation, in particular infrared radiation having a wavelength of at least 700 nm only with a low probability in the active region 20 is absorbed. For example, the active region can be formed by means of a lightly doped semiconductor layer 201 be formed during production on the substrate 26 is deposited.

A weakly doped semiconductor layer is understood in particular to mean a semiconductor layer which has a doping concentration of at most 10 ¹⁶ cm ^-3 .

After the deposition, in the lightly doped semiconductor layer, the second semiconductor region and the passive region 6 be formed. For example, the active region may have a doping concentration of between 10 ¹² cm ^-3 inclusive and 10 ¹⁵ cm ^-3 inclusive.

The first semiconductor area 21 however, it may have a doping concentration of at least 10 ¹⁷ cm ^-3 , for example between 10 ¹⁸ cm ^-3 inclusive and 10 ²⁰ cm ^-3 inclusive.

The thickness of the active region is preferably at most 10 μm, for example between 2 μm and 5 μm inclusive. Long-wave radiation has a greater penetration depth in silicon than short-wave radiation in the visible spectral range. The thinner the active area 20 is, the lower the proportion of the signal generated by absorption of infrared radiation.

In the first semiconductor sector 21 coming from the radiation entrance side 10 seen from the active area 20 is downstream, the recombination rate for electron-hole pairs, which are generated by absorption of radiation, compared to the recombination rate in the active region is greatly increased. The charge carriers generated in the first semiconductor region therefore reach the contacts only with a comparatively low probability 51 respectively 52 so that they provide no or at least no significant contribution to the signal of the radiation detector.

In contrast to radiation passing through the radiation entrance surface 10 enters, the optical path through the active area 20 when radiation enters through the side surface 23 be large even if the active area has only a small thickness. Therefore, even with a comparatively thin active area 20 the danger of a high signal component due to absorption of long-wave radiation in the active region 20 , This signal component by absorption of long-wave radiation in the active region 20 can by means of the passive area 6 be avoided or at least greatly reduced in an efficient way. The spectral sensitivity distribution of the radiation detector is so easily adapted to the sensitivity distribution of the human eye.

The radiation detector 1 , in particular the semiconductor body 2 Thus, both in the lateral direction and in the vertical direction can be designed such that radiation in the near infrared provides no or at least no significant contribution to the signal of the radiation detector.

For a sufficiently high absorption by the side surface 23 In the semiconductor body coupled infrared radiation has the heavily doped semiconductor region 61 in the lateral direction, preferably a width of between 30 μm and 200 μm inclusive, more preferably between 60 μm and 100 μm inclusive.

Preferably, the semiconductor body is already 2 itself, for instance by means of the described limitation of the active area 20 in the vertical direction, carried out such that the sensitivity distribution of the active region is adapted to or at least approximated to the predetermined sensitivity distribution. The better this adaptation, the lower the requirements for the filter structure 4 , For example, when using a dielectric filter structure, the number of layers required can be minimized. The manufacturer the cost of the radiation detector 1 can be reduced.

In the embodiment shown the radiation detector is merely exemplary according to a photodiode executed. Deviating from the active range can also according to a Phototransistor or a photo darlington be educated. Furthermore, the radiation detector with the active area also embedded in an integrated circuit be.

The result of a simulation of the spectral sensitivity of a radiation detector made according to the first embodiment is shown in FIG 2A as a curve 210 shown. The spectral sensitivity is shown as normalized relative responsivity R _N in percent relative to the maximum of responsiveness as a function of the vacuum wavelength of the incident radiation.

For comparison, the curve shows 220 the V _λ curve, which represents the spectral sensitivity distribution of the human eye. Both curves each have a maximum response at about 550 nm. For shorter as well as longer wavelengths, the responsiveness curve drops comparatively strongly, so that the radiation detector no longer has any significant responsivity for wavelengths smaller than 400 nm and for wavelengths greater than 700 nm.

In 23 the responsiveness of a conventional silicon photodiode is shown as a function of the wavelength λ. Here, the maximum response is in the range of about 830 nm, ie in the infrared spectral range. A comparison of this response curve with the curve 210 in 2A shows that by means of the described construction of the radiation detector 1 the sensitivity in the infrared spectral range can be almost completely suppressed and that the spectral sensitivity can continue to be adapted with very high accuracy to the sensitivity of the human eye. The described radiation detector is therefore particularly suitable as an ambient light sensor.

A second embodiment of a radiation detector is shown in FIG 3 schematically shown in sectional view. This second embodiment substantially corresponds to that in connection with the 1A and 1B described first embodiment. In contrast to this is the passive range 6 by means of a diode structure 7 educated.

The active area 20 is in a lightly doped semiconductor layer 201 educated. The lightly doped semiconductor layer 201 has a border area 202 on, which limits the active area in the lateral direction and along the side surface 23 runs. In 3 is the boundary of the border area 202 on the inside schematically represented by a dotted line.

A diode structure area 71 , the edge area 202 the weakly doped layer 201 and the first semiconductor layer 21 form the diode structure 7 , The diode structure area 71 has the same conductivity type as the second semiconductor region 22 and circumscribes this second semiconductor region 22 in lateral direction. The diode structure area 71 and the second semiconductor region 22 are hereby spaced apart in the lateral direction.

In the vertical direction, the diode structure area 71 and the second semiconductor region 22 from the radiation entrance surface 10 starting from the same extent. In particular, these regions can be formed during the production of the radiation detector in a common step.

The diode structure 7 is preferably electrically shorted. This is through an electrical connection 75 symbolically represented. In operation of the radiation detector is the diode structure 7 preferably connected to the ground potential.

For an electrical short circuit, for example, a low-resistance connection between the diode structure region 71 and the first semiconductor region 21 be educated. Already the damage of the crystal structure of the semiconductor body 2 along the side surface 23 can accomplish a sufficient conductivity. On the radiation entrance surface 10 is still a connecting layer 55 arranged, which the diode structure area 71 and the lightly doped semiconductor layer 201 connects electrically with each other. On such an external electrical connection of the diode structure region 71 with the weakly doped semiconductor layer 201 and / or the first semiconductor region 21 but can also be dispensed with.

Furthermore, on the radiation entrance surface 10 a separation layer 9 intended. This separating layer is expediently designed to be insulating and may in particular contain a material described in connection with the dielectric filter structure or consist of such a material. The separation layer covers the transition between the second semiconductor region 22 and the active area 20 on the radiation entrance surface. So can easily through the connection layer 55 caused electrical short circuit to the second semiconductor region 22 be avoided.

In operation of the radiation detector 1 flow Charge carriers in the edge area 202 be generated via the diode structure 7 and thus provide no significant contribution to the signal of the radiation detector. The border area 202 is expediently in the lateral direction so wide that through the side surface 23 irradiated radiation is almost completely absorbed in the edge region and not the active region 20 reached.

A third embodiment of a radiation detector 1 is in 4 shown in a schematic sectional view. This third embodiment corresponds essentially to that in connection with FIGS 1A and 1B described first embodiment.

In contrast to this is the passive range 6 by means of a recess 25 educated. During the production of the radiation detector, the recess can be produced, for example, by etching from the radiation entrance surface of the semiconductor body. The recess 25 extends through the lightly doped semiconductor layer 201 therethrough. In the lateral direction, the recess is limited 25 the active area 20 , The recess 25 is between the active area 20 and the side surface 23 of the semiconductor body 2 educated.

In a top view of the radiation detector 1 the recess is preferably formed like a frame, wherein the recess of the side surface 23 the radiation detector is spaced.

The recess 25 can be filled with a material containing the radiation passing through the side surface 23 of the semiconductor body 2 is radiated, at least partially absorbed. In particular, the filling material preferably has a high absorption coefficient in the infrared spectral range. This way you can avoid infrared radiation in the active area 20 could deliver an unwanted portion to the signal of the radiation detector is coupled into the active area. As a filling material, for example, polycrystalline silicon, which is preferably heavily doped.

Alternatively, the recess 25 also be filled with a filler that reflects the incident radiation. For example, the filler material may contain a metal or consist of a metal. Au, for example, has a high reflectivity in the infrared spectral range. Of course, other metals, such as Al, Ag, Ti, Pt, W or Ni or a metallic alloy, such as at least one of the metals mentioned, can be used.

Deviating from the embodiment shown, the recess may 25 also in the first semiconductor sector 21 extend into it. Furthermore, the recess must 25 in the vertical direction, not necessarily through the entire lightly doped layer 201 extend through.

A fourth embodiment of a radiation detector is shown in FIG 5 schematically shown in sectional view.

This fourth embodiment corresponds essentially to that in connection with FIGS 1A and 1B described first embodiment. In contrast, the radiation detector has a composite substrate with a substrate body 260 , an insulating layer 261 and a wear layer 262 on. The composite substrate may be embodied, for example, as an SOI substrate or as an SOS substrate.

The active area 20 is in the wear layer 262 educated. Furthermore, the first semiconductor region 21 and the second semiconductor region 22 formed in the wear layer. The substrate body 260 is from the active area 20 through the insulating layer 261 electrically isolated. Charge carriers generated in the substrate body by absorption of radiation can not enter the active region 20 thus make no contribution to the signal of the radiation detector. The volume used for generating the signal thus extends completely within the wear layer 262 ,

The thickness of the wear layer 262 is preferably at most 10 microns. An active area with a small thickness can be realized in a simple manner.

Furthermore, in contrast to the first embodiment, the first contact 51 and the second contact 52 on the same side of the semiconductor body 2 arranged. As related to the 1A and 1B the passive range can be described 6 by means of a heavily doped semiconductor region 61 be formed. Deviating from this, the passive range can be as in connection with the in 3 described second embodiment or with in connection with 4 be formed by means of a diode structure or a recess, so that is prevented by the side surface 23 of the semiconductor body 2 entering radiation enters the active area.

A fifth embodiment of a radiation detector is shown in FIG 6 illustrated by a schematic sectional view. This sixth embodiment corresponds essentially to that in connection with FIG 3 described second embodiment. In contrast to this, the semiconductor body 2 a cavity 29 on. The cavity 29 is in the first semiconductor region 21 educated. The active area 20 is in the vertical direction through the cavity 29 limited. The signal of the radiation detector 1 thus comes mainly from charge carriers that are between the radiation entrance surface 10 and the cavity 29 be generated by absorption of radiation.

The distance of the cavity 29 from the radiation entrance surface 10 is preferably at most 10 microns, so that the active region is limited in the vertical direction in a simple manner to a thickness of at most 10 microns.

The lateral extent of the cavity 29 is preferably at least as large as the lateral extent of the second semiconductor region 22 , This ensures that the charge carriers contributing to the signal are in the region between the radiation entrance surface 10 and the cavity 29 be generated. Charge carrier, the side of the cavity 29 or on the radiation entrance surface 10 On the other side of the cavity are generated, however, recombine without making a significant contribution to the signal. Deviating from the embodiment shown, the passive range 6 also as related to in the 1A and 1B described first and the basis of the 4 described third embodiment and thus be formed by means of a heavily doped region or by means of a recess.

A sixth embodiment of a radiation detector 1 is in 7 shown by a schematic sectional view. This sixth embodiment corresponds essentially to that in connection with FIGS 1A and 1B described first embodiment. In contrast, the active region is by means of the first semiconductor region 21 educated. On the second semiconductor area 22 remote side of the first semiconductor region 21 is another diode structure 8th educated. Here forms another diode structure area 81 and the first semiconductor region 21 the diode structure 8th , The further diode structure area 81 has the same conductivity type as the second semiconductor region 22 , In the vertical direction, the semiconductor body can thus have a pnp structure or an npn structure with regard to the line types.

The further diode structure 8th extends in the lateral direction up to the side surface 23 of the semiconductor body 2 , By means of the side surface, the further diode structure region 81 be shorted. Alternatively or additionally, the further diode structure region and the first semiconductor region 21 by means of a connecting layer arranged outside the semiconductor body, in particular as in connection with 3 described to be electrically connected.

By means of the further diode structure 8th is the active area 20 bounded in the vertical direction. Charge carriers in the first semiconductor region 21 at a great distance from the radiation entrance surface 10 , ie in the vicinity of the further diode structure region 81 can be generated via the further diode structure 8th drain and thus make no significant contribution to the signal of the radiation detector. The signal of the radiation detector is thus generated by charge carriers which are at a comparatively small distance from the radiation entrance surface 10 be generated by absorption of radiation. During operation of the radiation detector, it is preferably contacted in such a way that the further diode structure 81 about the first contact 51 connected to the ground potential.

Deviating from the described embodiment, the further diode structure region 81 also by means of the substrate 26 be formed. On a separate, between the substrate 26 and the first semiconductor region 21 arranged layer can be dispensed with in this case.

Furthermore, the passive range of the described embodiment may deviate also as in connection with 3 and 4 be formed by means of a diode structure or by means of a recess.

The described embodiments are further distinguished by good compatibility with processes of conventional Si technology. The radiation detectors 1 are therefore simple, inexpensive and easy to integrate into other components produced.

The The invention is not by the description based on the embodiments limited. Much more For example, the invention includes every novel feature as well as every new combination of features, in particular any combination of features in the claims includes, even if this feature or this combination itself not explicitly in the claims or the embodiments is specified.

Claims (15)

Radiation detector ( 1 ) with a semiconductor body ( 2 ) having an active region ( 20 ), a radiation entrance surface ( 10 ) and one the semiconductor body ( 2 ) laterally delimiting side surface ( 23 ), wherein along the side surface ( 23 ) at least partially a passive area ( 6 ) is formed, which at least partially prevents that Radiation traveling laterally towards the active area ( 20 ) for generating a signal of the radiation detector ( 1 ) in the active area ( 20 ) contributes. Radiation detector according to Claim 1, in which the passive region ( 6 ) between the active area ( 20 ) and the side surface ( 23 ) of the semiconductor body ( 2 ) runs. Radiation detector according to Claim 1 or 2, in which the passive region ( 6 ) the active area ( 20 ) rotates laterally. Radiation detector according to one of Claims 1 to 3, in which the passive region ( 6 ) by means of a recess ( 25 ) in the semiconductor body ( 2 ), wherein the recess is filled with a filling material which absorbs or reflects the incident radiation. Radiation detector according to one of Claims 1 to 3, in which the passive region ( 6 ) is formed by means of a semiconductor material that is at least 100 times as heavily doped as the semiconductor material of the active region ( 20 ). Radiation detector according to one of Claims 1 to 3, in which the passive region ( 6 ) by means of a diode structure ( 7 ) is formed. Radiation detector according to Claim 6, in which the diode structure ( 7 ) is shorted. Radiation detector according to one of the preceding claims, in which on the radiation entrance surface ( 10 ) of the semiconductor body ( 2 ) a filter structure ( 4 ) is trained. Radiation detector according to one of the preceding claims, in which the active region ( 20 ) on the radiation entrance surface ( 10 ) of the semiconductor body ( 2 ) facing away in the vertical direction by means of an insulating layer ( 261 ) is limited. Radiation detector according to one of Claims 1 to 8, in which the semiconductor body ( 2 ) a cavity ( 29 ) having the active area ( 20 ) on the radiation entrance surface ( 10 ) facing away from the side. Radiation detector according to one of Claims 1 to 8, in which the active region ( 20 ) is formed by means of a semiconductor layer which has a thickness of between 1 μm and 8 μm inclusive, preferably between 2 μm and 5 μm inclusive, and to which on the radiation entrance side ( 10 ) facing away from a heavily doped semiconductor layer having a doping concentration of at least 1 × 10 ¹⁸ cm ^-3 adjacent. Radiation detector according to claim 10, in which on the radiation entrance side ( 10 ) facing away from the active area ( 20 ) another diode structure ( 8th ) is trained. Radiation detector according to one of the preceding claims, in which the active region ( 20 ) Contains silicon. Radiation detector according to one of the preceding claims, in which the active region ( 20 ) is formed according to a photodiode, a phototransistor or a photo Darlington circuit. Radiation detector according to one of the preceding claims, which is designed such that a spectral sensitivity distribution of the radiation detector ( 1 ) is adapted to that of the human eye.