CN100474595C - Semiconductor device - Google Patents
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- CN100474595C CN100474595C CNB2007100858101A CN200710085810A CN100474595C CN 100474595 C CN100474595 C CN 100474595C CN B2007100858101 A CNB2007100858101 A CN B2007100858101A CN 200710085810 A CN200710085810 A CN 200710085810A CN 100474595 C CN100474595 C CN 100474595C
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Abstract
There are provided a structure of a semiconductor device in which low power consumption is realized even in a case where a size of a display region is increased to be a large size screen and a manufacturing method thereof. A gate electrode in a pixel portion is formed as a three layered structure of a material film containing mainly W, amaterial film containing mainly Al, and a material film containing mainly Ti to reduce a wiring resistance. A wiring is etched using an IPC etching apparatus. The gate electrode has a taper shape and the width of a region which becomes the taper shape is set to be 1 mu m or more.
Description
The application be that February 28, application number in 2002 are 02106559.4 the applying date, denomination of invention divides an application for the application for a patent for invention of " semiconductor device and manufacture method thereof ".
Technical field
The present invention relates to have the semiconductor device and the manufacture method thereof of the circuit that constitutes by thin-film transistor (hereinafter referred to as TFT).It is that the device of representative and its are gone up the electronic device of this device of installation as a part that the present invention for example relates to liquid crystal display device (Liquid crystal module wherein is installed).
Notice that the semiconductor device in this specification is represented the device by utilizing characteristic of semiconductor to work usually, electro-optical device, luminescent device, semiconductor circuit and electronic device all are semiconductor device for every kind.
Background technology
In recent years, had been noted that the technology of utilizing the semiconductive thin film (several approximately thick) that is formed on the substrate with insulating surface to constitute thin-film transistor (TFT) to hundreds of nm.This thin-film transistor is widely used in electronic device such as IC or electro-optical device, and its development as the switch element of image display device of special requirement.
Usually, liquid crystal display device is known as image display device.Owing to compare with the passive liquid crystal display part, can obtain high-resolution picture, therefore in various situations, adopt active matrix liquid crystal display device.According to active matrix liquid crystal display device, when driving is arranged in the pixel capacitors of matrix, display graphics on phosphor screen.In more detail, when applying voltage between the opposite electrode of selecting pixel capacitors and corresponding selection pixel capacitors, modulate the liquid crystal layer between pixel capacitors and opposite electrode optically, and this optical modulation observed person is identified as display graphics.
The scope of application of this active matrix liquid crystal display device has enlarged.Increase along with the increase of phosphor screen size for the requirement of high-resolution, higher aperture efficiency (opening ratio) and high reliability more.Simultaneously, also increase for the raising of productivity ratio and the requirement of cost reduction.
Usually, when adopting aluminium to make TFT, form projection such as hillock or whisker by heat treatment, and the aluminium atom diffusion is to channel formation region as the material of the grating routing of above-mentioned TFT.The job failure of TFT and the degeneration of TFT characteristic like this, have just been produced.For addressing this problem, adopt the metal material of heat-resisting processing, be generally and have the high-melting point metal element.But, occurred owing to the phosphor screen size increases the problem that the cloth line resistance is increased, and caused the increase of power consumption etc.
Summary of the invention
Therefore, even the purpose of this invention is to provide a kind of structure and manufacture method thereof that when the phosphor screen size increases, also can realize the semiconductor device of low-power consumption.
According to the present invention, grid structure is made into laminated construction, the material membrane that wherein mainly contains TaN or W is used as the ground floor that prevents to the channel formation region diffusion, and the low electrical resistant material film that mainly contains Al or Cu is used as the second layer, and the material membrane that mainly contains Ti is used as the 3rd layer.Like this, reduced the resistance of wiring.
According to disclosed in this manual structure of the present invention, comprise being characterised in that by the semiconductor device that is formed on semiconductor layer on the insulating surface, is formed on the dielectric film on the semiconductor layer and is formed on the TFT that the grid on the dielectric film constitutes and comprising: comprise the pixel parts that has by a n channel TFT of the source wiring made from the grid same material; The drive circuit that comprises the circuit that constitutes by the 2nd n channel TFT and the 3rd n channel TFT; With by the terminal part made from the grid identical materials.
In said structure, grid is characterised in that to have the material membrane that mainly contains TaN (ground floor), mainly contain the material membrane of Al (second layer) and mainly contain the layer structure of the material membrane of Ti (the 3rd layer).And grid is characterised in that to have the material membrane that mainly contains W (ground floor), mainly contain the material membrane of Al (second layer) and mainly contain the laminated construction of the material membrane of Ti (the 3rd layer).
According to this grid structure, when adopting ICP (inductively coupled plasma) etching method, the end of grid can form taper.Notice that the cone angle in this specification produces the angle that horizontal surface and side surface by material layer form.And in this manual, the side surface with cone angle is called taper, and the part with taper becomes the tapering.
And, in said structure, the invention is characterized in that the 2nd n channel TFT and the 3rd n channel TFT constitute EEMOS circuit or EDMOS circuit.Drive circuit of the present invention is made of nmos circuit, and this nmos circuit only is made of n channel TFT sS, and the TFTs of pixel parts also is made of n channel TFT s.Like this, simplified technology.General drive circuit is to design on the cmos circuit basis that n channel semiconductor element and p channel semiconductor element by mutual compensation combination constitute.But according to the present invention, drive circuit is only combined by n channel TFT s.
In addition, in order to realize said structure,, provide the method for making semiconductor device according to structure of the present invention, this semiconductor device comprises drive circuit, pixel parts and the terminal part that is positioned on the insulating surface, and this method may further comprise the steps: form semiconductor layer on insulating surface; On semiconductor layer, form first dielectric film; On first dielectric film, form the source wiring of grid, pixel parts and the electrode of terminal part; Make mask with grid, in semiconductor layer, add the impurity element that the n type is provided, so that form n type impurity range; The etching grid is to form the tapering; Form the source wiring of covering pixel parts and second dielectric film of terminal part; With the grating routing and the source wiring that on second dielectric film, form drive circuit.
In said structure, it is characterized in that, in the step of the electrode of source wiring that forms grid, pixel parts and terminal part, the material membrane that mainly contain the material membrane of TaN, mainly contains the material membrane of Al and mainly contain Ti forms lamination, adopt mask to carry out etching then, so that form grid, the source wiring of pixel parts and the electrode of terminal part.And, in said structure, it is characterized in that, in the step of the electrode of source wiring that forms grid, pixel parts and terminal part, the material membrane that mainly contain the material membrane of W, mainly contains the material membrane of Al and mainly contain Ti forms lamination, adopt mask to carry out etching then, so that form grid, the source wiring of pixel parts and the electrode of terminal part.
And, according to the present invention, can make and have at the liquid crystal display device of pixel parts described in the said structure and drive circuit or have the luminescent device of the OLED that is included in pixel parts described in the said structure and drive circuit.
And,,, therefore simplified the manufacturing step of liquid crystal display device or luminescent device, and reduced manufacturing cost owing to omitted the manufacturing step of p channel TFT according to the present invention.
Description of drawings
Figure 1A-1C represents the manufacturing step of AM-LCD;
Fig. 2 A and 2B represent the manufacturing step of AM-LCD;
Fig. 3 represents the manufacturing step of AM-LCD;
Fig. 4 is the top view of pixel;
Fig. 5 represents the outward appearance of Liquid crystal module;
Fig. 6 is the profile of transmission-type liquid crystal display device;
Fig. 7 A and 7B represent the structure of nmos circuit;
Fig. 8 A and 8B represent the to be shifted structure of resistor;
Fig. 9 is the top view of pixel parts of the present invention;
Figure 10 is the profile of pixel parts of the present invention;
Figure 11 A-11C represents the example of electronic installation;
Figure 12 A and 12B represent the example of electronic installation;
Figure 13 is the SEM image of observing after etching;
Figure 14 is the SEM image of observing after etching;
Figure 15 represents the relation between reliability (20 hours safe voltages and 10 years safe voltages) and the Lov length in the TFT of drive circuit;
Figure 16 A and 16B are respectively top view and its profiles of EL assembly;
Figure 17 is the profile of EL assembly;
Figure 18 represents the structure of grid side drive circuit;
Figure 19 is the sequential chart of decoder input signal; With
Figure 20 represents the structure of source drive circuit.
Embodiment
To introduce embodiments of the present invention below.
At first, on substrate, form underlying insulation film, form semiconductor layer by first lithography step then with reservation shape.
Then, form the dielectric film (comprising gate insulating film) that covers semiconductor layer.Stacked first conducting film, second conducting film and the 3rd conducting film on dielectric film.Utilize second lithography step that stack membrane is carried out first etching processing, so that form grid, the source wiring of pixel parts and the electrode of terminal part that constitutes by first conductive layer and second conductive layer.Note, in the present invention, after forming grid, on interlayer dielectric, form grating routing.
Next, under the state that the Etching mask that forms keeps, add the impurity element (phosphorus etc.) that the n type is provided in second lithography step, so that form n type impurity range (having high concentration) with self-aligned manner to semiconductor layer.
Then, under the state that the Etching mask that forms in second lithography step keeps, change etching condition, carry out second etching processing, form first conductive layer (first width), second conductive layer (second width) and the 3rd conductive layer (the 3rd width) with tapering.Notice that first width is wideer than second width, second width is wideer than the 3rd width.Here, the electrode that is made of first conductive layer, second conductive layer and the 3rd conductive layer becomes the grid (first grid) of n channel TFT.
The material membrane that mainly contains TaN or W is used as first conductive layer, for preventing that this first conductive layer contacts with dielectric film to the channel formation region diffusion.And the low electrical resistant material film that mainly contains Al or Cu can be used as second conductive layer.In addition, have material membrane low contact resistance, that mainly contain Ti and can be used as the 3rd conductive layer.
Then, after removing Etching mask, make mask, in semiconductor layer, add the impurity element that the n type is provided by dielectric film with first grid.
Afterwards, form Etching mask, and, add the impurity element that the n type is provided in order to reduce the cut-off current of the TFT in the pixel parts by the 3rd photoetching process (step).
Then, form interlayer dielectric and also form nesa coating thereon.Utilize the 4th photoetching process (step) composition nesa coating, form pixel capacitors.Then, utilize the 5th lithography step to form contact hole.Here, form contact hole, contact hole that arrives grid that arrives impurity range and the contact hole that arrives source wiring.
Then, form the conducting film of making by low-resistance metal material.Form grating routing, be used to connect the electrode and the electrode that is used to be connected pixel capacitors and impurity range of source wiring and impurity range by the 6th lithography step.In the present invention, grating routing is electrically connected with first grid or second grid by the contact hole that is provided in the interlayer dielectric.And source wiring is electrically connected with impurity range (source region) by the contact hole that is provided in the interlayer dielectric.In addition, the electrode that is connected with pixel capacitors is electrically connected with impurity range (drain region) by the contact hole that is provided in the interlayer dielectric.
Like this,, promptly adopt six masks by carrying out lithography step altogether six times, can form comprise have pixel TFT (n channel TFT) pixel parts and have a component substrate of the drive circuit of the EEMOS circuit (n channel TFT s) shown in Fig. 7 A.Note, show the example of making transmissive display spare here.But, also can adopt material to be used for pixel capacitors and to make reflection type display device with high reflection characteristic.When making reflection type display device,, therefore can adopt five masks to form component substrate because pixel capacitors can form simultaneously with grating routing.
And, can make active matrix light emitting device with OLED (organic luminescent device).Even under the situation of luminescent device, whole drive circuit is made of n channel TFT s, and pixel parts also is made of a plurality of n channel TFT s.In the luminescent device that adopts OLED, the TFT that is used as switch element at least carries the TFT of electric current to be provided at each pixel with being used for to OLED.No matter how are the circuit structure of pixel and driving method, are electrically connected with OLED and can make the n channel TFT to the TFT of its conveying electric current.
OLED has and comprises by apply electric field (electroluminescence) to it and realize layer (hereinafter referred to as organic luminous layer), anode and the negative electrode of luminous organic compound (luminous organic material).The luminous light emission (phosphorescence) that comprises that the light that produces is launched (fluorescence) and produced when singlet excited turns back to ground state when triplet excited state turns back to ground state of organic compound.Under the situation of luminescent device of the present invention, in the above-mentioned light emission, can adopt wherein a kind of light emission, also can adopt two kinds of light emissions.
Note, in this manual, be formed on anode among the OLED and all layers between the negative electrode and be defined as organic luminous layer.Particularly, organic luminous layer comprises luminescent layer, hole injection layer, electron injecting layer, hole transporting layer and electron supplying layer.Basically, OLED has the wherein stacked in order structure of anode, luminescent layer and negative electrode.Except this structure, also have following situation: OLED to have stacked in order structure of wherein anode, hole injection layer, luminescent layer and negative electrode or the stacked in order structure of anode, hole injection layer, luminescent layer, electron supplying layer and negative electrode wherein.
And, before forming conducting film, when forming EDMOS circuit shown in Fig. 7 B by combination enhancement mode or depletion type, be pre-formed mask, and to becoming 13 family's elements (being preferably boron) of selecting to add the element (being preferably phosphorus) of 15 families that belong to periodic table or belong to periodic table in the semiconductor layer of channel formation region.In this case, can adopt seven masks to form component substrate.
Here adopted the n channel TFT to be described.But, need not illustrate, replace n type impurity element can form the p channel TFT by adopting p type impurity element.In this case, whole drive circuit is made of p channel TFT s, and pixel parts also is made of p channel TFT s.
On the basis of embodiment, will introduce the present invention who utilizes said structure to realize below in more detail.
(embodiment)
[embodiment 1]
Introduce embodiments of the invention with Figure 1A-1C to Fig. 6 below.Here, the method for the TFTs (having only n channel TFT s) that makes TFTs that constitutes pixel parts and the drive circuit that constitutes the periphery that is provided at pixel parts on the same substrate simultaneously will be presented in detail.
In Figure 1A, glass substrate, quartz substrate, ceramic substrate etc. can be used as substrate 100.Also can adopt at the bottom of silicon substrate, metal substrate or the stainless steel lining that forms dielectric film from the teeth outwards.And, can also adopt stable on heating plastic with anti-treatment temperature in the example.
Then, shown in Figure 1A, on substrate 100, form by dielectric film such as silicon oxide film, silicon nitride film or silicon oxynitride film (SiO
xN
y) underlying insulation film 101 made.As exemplary, adopt the wherein laminated construction of underlying insulation film 101 employing double-layer structures, adopt SiH
4, NH
3And N
2O is as reacting gas, and forming thickness is the first silicon oxynitride film 101a of 50nm-100nm, uses SiH
4And N
2O does reacting gas, and forming thickness is the second silicon oxynitride film 101b of 100nm-150nm.And thickness is that 10nm or following silicon nitride film can be used as underlying insulation film 101.When adopting silicon nitride film,, also has the effect that in the air-breathing step that will carry out in the back, improves gettering efficiency except as the effect as the barrier layer.When air-breathing, nickel can move to the zone with hyperoxia concentration.Like this, adopting silicon nitride film is very effective as the underlying insulation film that contacts with semiconductor film.And, can adopt the three-decker of wherein stacked in order first silicon oxynitride film, second silicon nitride film and silicon nitride film.
By making the amorphous semiconductor membrane crystallization that is formed on the underlying insulation film 101, obtain semiconductor film as active layer.The thickness of amorphous semiconductor film is 30nm-60nm.Afterwards, adopt the metallic element (being nickel in this example) with the catalytic action that promotes crystallization, apply the nickel acetate solution of the 1ppm-100ppm nickel that contains the weight conversion with spinner on the surface of amorphous semiconductor film, formation contains catalyst layer.
Keep amorphous semiconductor film and contain catalytic elements layer state of contact, be used for the heat treatment of crystallization.In this example, heat treatment is undertaken by the RTA method.The lamp source that is used to heat was opened 1 second-60 seconds, and preferred 30 seconds-60 seconds, and repeat this operation 1 time-10 times, preferred 2 times-6 times.Though the luminous intensity of lamp source is set at any intensity, the heating semiconductor film is so that 600 ℃-1000 ℃, preferred about 650 ℃ of-750 ℃ of instantaneous heating.Even obtain this high temperature, semiconductor film is heated and does not have the situation of substrate 100 bendings own and distortion immediately.In this way, the amorphous semiconductor membrane crystallization obtains the crystal semiconductor film.
In order further to improve crystallization than (percentage of crystallised component cumulative volume in film) with repair the defective of staying in the crystal grain, usefulness laser radiation crystal semiconductor film.As laser, can adopt the excimer laser with 400nm or following wavelength, second harmonic or its triple-frequency harmonics of YAG laser.Under any circumstance, adopt the pulse laser of repetition rate, utilize optical system that this laser focusing is become 100mJ/cm with about 10Hz-1000Hz
2-400mJ/cm
2The laser treatment that is used for the crystal semiconductor film can be carried out under the overlap ratio of 90%-95%.
Note, show the example that adopts pulse laser here.But, also can adopt continuous oscillation laser.For the crystal that obtains having big crystallite dimension when the amorphous semiconductor membrane crystallization, preferred employing can produce the solid state laser of continuous oscillation, and the second harmonic that uses first-harmonic is to one of four-time harmonic.Usually, can adopt Nd:YVO
4Laser (first-harmonic: second harmonic 1064nm) (532nm) or triple-frequency harmonics (355nm).When adopting the continuous oscillation laser, from having the continuous oscillation YVO of 10W output
4The laser emitted laser is converted to harmonic wave by non-linear optical element.And, have and in resonator, locate YVO
4The method of crystal and non-linear optical element and emission harmonic wave.Then, utilize optical system to make laser preferably form rectangle or ellipse on the irradiating surface and shine on the target to be processed.At this moment, need about 0.01MW/cm
2-100MW/cm
2(be preferably 0.1MW/cm
2-10MW/cm
2) energy density.Then, the speed of semiconductor film with about 10cm/s-2000cm/s can be moved with respect to laser, so that illuminated.
Note, adopt the technology of irradiating laser after usefulness nickel is as the thermal crystalline of the metallic element that promotes the silicon crystallization here.But, can be under the situation of not adding nickel, by continuous oscillation laser (YVO
4The second harmonic of laser) makes the amorphous silicon film crystallization.
Then, carry out air-breathing processing, so that remove the catalytic elements that is included in the crystal semiconductor film.On the crystal semiconductor film, form the barrier layer.As the barrier layer, form perforated membrane, make catalytic elements (nickel) can move to air-breathing part (cite) by heat treatment, the etching liquid that uses in removing the step of suction location is impermeable then.For example, can adopt by handle chemical oxide film or the Si oxide (SiO that forms with Ozone Water
x) film.In this manual, the film with this specific character is called perforated membrane especially.
Then, the semiconductor film that comprises inert gas elements forms air-breathing part.In this example, utilizing plasma CVD method, sputtering method etc. to form the stage of film or passing through the stage that ion doping method or ion implantation are added after film forms, it is 1 * 10 that formation comprises concentration
19-1 * 10
22/ cm
3, be preferably 1 * 10
20-1 * 10
21/ cm
3The semiconductor film of inert gas elements.
Afterwards, adopt the heat treatment of lamp source such as the heat treatment of RTA method or employing stove, make catalytic elements move longitudinally to air-breathing part.This heat treatment also is used as annealing.About heating condition, the lamp source that is used to heat was opened 1 second-60 seconds, and preferred 30 seconds-60 seconds, this operation repeated preferred 2 times-6 times 1 time-10 times.Though the light emissive porwer of lamp source is set at any intensity, semiconductor film is heated so that 600 ℃-1000 ℃, preferred about 700 ℃ of-750 ℃ of instantaneous heating.
Finish after the air-breathing step, the air-breathing part that selective etching is made of amorphous semiconductor is so that remove this part.As lithographic method, can adopt the dry etching that under situation, utilizes C1F3 without plasma, or by aqueous slkali as comprising hydrazine or tetraethylammonium hydroxide (chemical formula: (CH
3)
4The wet etching of the aqueous solution NOH).At this moment, barrier layer 106 is used as etching stop layer.And, utilize hydrofluoric acid to remove barrier layer 106 in the back in the step.In order to improve crystallization, can irradiating laser after crystallisation step.
Subsequently,, handle the crystal semiconductor film that obtains, form the semiconductor layer 102-106 that separates with island shape by being etched into reservation shape.
Form after the semiconductor layer 102-106,, provide the impurity element of p type to its interpolation for the threshold value (Vth) of controlling the n channel TFT.The element that belongs to periodic table 13 families is known as the impurity element that the p type is provided to semiconductor as boron (B), aluminium (Al) or gallium (Ga).
Next, form the gate insulating film 107 that covers the semiconductor layer 102-106 that separates with island.Gate insulating film 107 is to utilize plasma CVD method or sputtering method and film formed by the insulation that comprises silicon, and its thickness setting is 40nm-150nm.。Certainly, gate insulating film 107 can also be used as individual layer dielectric film or its laminated construction that comprises silicon.
When adopting silicon oxide film, utilize plasma CVD method mixing TEOS (tetraethyl orthosilicate) and O
2, reaction pressure is set at 40Pa, and underlayer temperature is set at 300 ℃-400 ℃.Then, at 0.5W/cm
2-0.8W/cm
2High frequency (13.56MHz) power density under discharge, form silicon oxide film.Afterwards, when the silicon oxide film of formation like this is heat-treated, can obtain optimum performance under 400 ℃-500 ℃ as gate insulating film.
Aluminium (Al) the film 108b of conduct second conducting film that thickness is tungsten (W) the film 108a of conduct first conducting film of 20nm-100nm, thickness is 100nm-500nm and titanium (Ti) the film 108c that thickness is 20nm-100nm superpose on gate insulating film 107.Here, the thickness that superposes in order on gate insulating film is that tungsten film, the thickness of 50nm is that the aluminium of 500nm and the alloy of titanium (Al-Ti) film and thickness are the titanium film of 30nm.
The electric conducting material that is used to form grid is that the compound-material that by the element that is selected from the group that is made of Ta, W, Ti, Mo, Al and Cu, mainly comprises the alloy material of above-mentioned element or mainly comprise above-mentioned element constitutes.With the polysilicon film with impurity element such as phosphorus doping is that the semiconductor film of representative can also be used as first conducting film.In addition, can also adopting wherein, first conducting film is made of tungsten (W) film, second conducting film is made of the combination that is made of titanium (Ti) film with the 3rd conducting film the Cu film, wherein first conducting film is made of tantalum nitride (TaN) film, the combination that second conducting film is made of titanium (Ti) film aluminium (Al) film formation and the 3rd conducting film, wherein first conducting film is made of tantalum nitride (TaN) film, the combination that second conducting film is made of the Al film, and wherein first conducting film is made of tantalum nitride (TaN) film, second conducting film is made of the Cu film, with of the combination of the 3rd conducting film by titanium (Ti) film formation.
Then, shown in Figure 1B, form the mask 110-115 that constitutes by resist, carry out etching processing, be used to form grid and wiring by the light source step of exposure.Under first etching condition and second etching condition, carry out first etching processing.Etching preferably adopts ICP (inductively coupled plasma) etching method hereto.When adopt the ICP etching method and suitably the control etching condition (impose on the power of coil form electrode amount, impose on the power of the electrode that is positioned at substrate side amount, be positioned at the temperature etc. of the electrode of substrate side) time, film can be etched to predetermined taper.Note, with Cl
2, BCl
3, SiCl
4, CCl
4Deng being the chloride system gas of representative, with CF
4, SF
6, NF
3Deng for the fluorine of representative is a gas, or O
2Can be used as suitable etching gas.
Though the etching gas that uses is not limit, and adopts BCl here
3, Cl
2And O
2Be suitable.The ratio of their reacting gas flow velocity is set at 65:10:5 (sccm).Apply RF power under 1.2Pa pressure, for the coil form electrode, produce plasma, and carried out etching 117 seconds with 450W and 13.56MHz.And, carry for substrate side (sample stage) and have the RF power of 300W and 13.56MHz, so that apply negative automatic bias basically.Notice that the area size that is positioned at the electrode of substrate side is 12.5cM * 12.5cm.And coil form electrode (here for the quartz disk of coil wherein is provided) is a disk, and its area size is the 25cm diameter.Etching W film under first etching condition forms taper with the end of first conductive layer.
After this, first etching condition is changed into second etching condition.CF
4, Cl
2And O
2Be used as etching gas, their gas flow rates separately are than being 25:25:10 (sccm).The RF power delivery that will have 500W and 13.56MHz under 1Pa pressure is given the coil form electrode, so that produce plasma, carries out etching thus about 30 seconds.And, carry for substrate side (sample stage) and have the RF power of 20W and 13.56MHz, so that apply negative automatic bias basically.Mixed C therein
F4And Cl
2Second etching condition in, W film and TaN film are etched into same degree.Notice that in order not carry out etching under the situation that stays any residue on the gate insulating film, etch period preferably increases with the speed of about 10%-20%.
In first etching processing, when the shape of the mask that is made of resist was suitable, the end of first and second conductive layers was owing to the effect of the bias voltage that imposes on substrate side becomes taper.The angle in tapering is 15 °-45 °.In this way, form the first shaping conductive layer 117-122 that constitutes by first conductive layer, second conductive layer and the 3rd conductive layer (the first conductive layer 117a-122a, the second conductive layer 117b-122b and the 3rd conductive layer 117c-122c) by first etching processing.Reference marker 116 expression gate insulating films.The zone that the first shaping conductive layer 117-122 of no use covers about 20-50nm that is etched is so that the formation thinner area.
Here, prepare sample, and etching condition is experimentized.About this sample, with the same under in this example the situation, stacked thickness is that tungsten film, the thickness of 50nm is that the aluminium of 500nm and the alloy of titanium (Al-Ti) film and thickness are the titanium film of 30nm on quartz substrate in order.Figure 13 be with above-mentioned first etching processing the same terms under carry out etching after the image by obtaining immediately with the SEM observation sample.Like this, the shape of the conductive layer shown in Figure 13 can be assumed to be the first shaping conductive layer.
Under the situation of not removing the mask 110-115 that constitutes by resist, carry out second etching processing, shown in Fig. 1 C.BCl
3And Cl
2Be used as etching gas, their gas flow rate ratios separately are set at 20/60 (sccm).The RF power delivery that will have 600W and 13.56MHz under 1.2Pa pressure is given the coil form electrode, carries out etching thus.And, carry RF power for substrate side (sample stage) with 100W and 13.56MHz.Etching second conductive layer under the 3rd etching condition of in second etching processing, carrying out.In this way, anisotropically etching contains the very aluminium film of a little amount of titanium under above-mentioned the 3rd etching condition, so that form the second shaping conductive layer 124-129 (the first conductive layer 124a-129a, the second conductive layer 124b-129b and the 3rd conductive layer 124c-129c).Reference marker 123 expression gate insulating films.The zone that the first shaping conductive layer 124-129 of no use covers is by slight etching, so that form thinner area.And, shown in Figure 1B and 1C, suppose that the tapering of first conductive layer has identical length.But in fact, because the correlation of wiring width, the tapering length of first conductive layer can change according to wiring width.
Here, as in above-mentioned situation, the preparation sample also experimentizes to etching condition.As sample, with the same under in this example the situation, stacked thickness is that tungsten film, the thickness of 50nm is that the aluminium of 500nm and the alloy of titanium (Al-Ti) film and thickness are the titanium film of 30nm on quartz substrate in order.Figure 14 be with above-mentioned first etching processing the same terms under carry out etching carry out second etching processing then after the image by obtaining immediately with the SEM observation sample.Like this, the shape of the conductive layer shown in Figure 14 can be assumed to be the second shaping conductive layer.
Then, under the situation of not removing the mask that constitutes by resist, carry out first doping treatment, so that add the impurity element that the n type is provided to semiconductor layer.This doping treatment can be undertaken by ion doping method or ion implantation.About the condition of ion doping method, dosage setting is 1.5 * 10
11Atoms/cm
2, accelerating voltage is set at 60keV-100keV.Belong to periodic table 15 families element, be generally phosphorus (P) or arsenic (As) is used as the impurity element that the n type is provided.In this case, conductive layer 124-128 becomes the mask of the impurity element that the n type is provided, and therefore forms the first impurity range 123-127 with self-aligned manner.Give the first impurity range 130-134 with 1 * 10
16/ cm
3-1 * 10
17/ cm
3Concentration range add the impurity element that the n type is provided.
Then, shown in Fig. 2 A, form the mask of making by resist 135 and 136, and carry out second doping treatment.Mask 135 is to be used for protecting the channel formation region of semiconductor layer of the n channel TFT s that constitutes drive circuit and the mask of its external zones.Mask 136 is to be used for protecting the channel formation region of semiconductor layer of the TFT that constitutes pixel parts and the mask of its external zones.And, in Fig. 2 A, for simplicity, suppose that the tapering of first conductive layer has equal length.But in fact, the tapering length of first conductive layer can change according to wiring width.Like this, when a plurality of wiring with various wirings width is provided on same substrate, the width of doped regions to differ from one another.
About the condition of the ion doping method in second doping treatment, dosage setting is 1.5 * 10
15Atoms/cm
2, accelerating voltage is set at 60keV-100keV.Doping Phosphorus (P).Here, adopt the film thickness difference between the second shaping conductive layer 124-128 and gate insulating film 123 in each semiconductor layer, to form impurity range.Certainly, do not give the zones interpolation phosphorus (P) that covers with mask 135 and 136.In this way, form the second impurity range 180-182 and the 3rd impurity range 137-141.Give the 3rd impurity range 137-141 with 1 * 10
20/ cm
3-1 * 10
21/ cm
3Concentration range add the impurity element that the n type is provided.And, by the film thickness difference of gate insulating film, form second impurity range with the concentration lower than the 3rd impurity range.Like this, give second impurity range with 1 * 10
18/ cm
3-1 * 10
19/ cm
3Concentration range add the impurity element that the n type is provided.
By above-mentioned steps, in each semiconductor layer, form impurity range with n type conduction type.The second shaping conductive layer 124-127 becomes grid.And the second shaping conductive layer 128 becomes an electrode that constitutes the holding capacitor in the pixel parts.In addition, the source wiring in the second shaping conductive layer, the 129 formation pixel parts.
Then, form first interlayer dielectric 151 that covers whole surface basically.First interlayer dielectric 151 forms by plasma CVD method or sputtering method, and is made of the dielectric film that contains silicon and hydrogen, and thickness is 100-200nm.An one preferred example is that the thickness that forms by plasma CVD method is the silicon oxynitride film of 150nm.Certainly, first interlayer dielectric is not limited to silicon oxynitride film, can adopt individual layer or its laminated construction of other dielectric film that contains silicon.
Afterwards, add the activation step of the impurity element in each semiconductor layer to.Activation is to realize by the heat treatment of adopting furnace annealing or clean stove.Heat treatment in blanket of nitrogen 400-700 ℃, be generally under 410-500 ℃ and carry out.Note, in addition, can adopt laser annealing method or rapid thermal annealing method (RTO method).
Utilize above-mentioned activation to handle simultaneously, be used as nickel air-breathing of catalyst at the 3rd impurity range 137-141 that contains phosphorus with high concentration, so that reduce the concentration of the nickel in the semiconductor layer that mainly becomes channel formation region.The result is about having the TFTs of channel formation region, to reduce the cut-off current value.And, owing to its high degree of crystallinity obtains high field effect mobility, and can realize better characteristic.
Next, as shown in Figure 3, on first interlayer dielectric 151, form second interlayer dielectric of making by organic insulating material 152.Then, form contact hole that arrives source wiring 127 and the contact hole that arrives each impurity range.
Afterwards, form wiring and the pixel capacitors that constitutes by Al, Ti, Mo, W etc.For example, adopting thickness is the stacked film of the Ti film of 50nm-250nm and the alloy film (alloy film of Al and Ti) that thickness is 300nm-500nm.In this way, form wiring (source wiring and leak routing) 153-158, grating routing 160, connecting wiring 159, pixel capacitors 161 and capacitor wiring 162.
In this way, can on same substrate, form drive circuit 406 and have n channel TFT 404 and the pixel parts 407 of holding capacitor 405 with n channel TFT s 401,402 and 403.In this manual, for simplicity, this substrate is called the active matrix substrate.Notice that n channel TFT 401 has identical structure with n channel TFT 403.
And according to conventional methods, following situation is arranged: wherein impurity element moves in the zone below the grid according to doping condition, and form that width is about 0.1 μ m with grid stack and impurity range with concentration gradient.But, in this example, width setup be 0.5 μ m or more than, preferred 1 μ m or more than.Like this, the TFT structure is different from conventional structure.
Adopt these n channel TFT s to form shift-register circuit, buffer circuits, level shift circuit, latch cicuit etc.Particularly, under the situation of the buffer circuits with high driving voltage, because the degeneration that causes of hot carrier's effect, n channel TFT 401 or 403 structure are fit in order to prevent.
In the pixel parts 407 pixel TFT 404 have channel formation region 171, be formed on first impurity range 172 of the second shaping conductive layer, 128 outsides that constitute grid and respectively be used as the 3rd impurity range 173 in source region or drain region.In addition, in the semiconductor layer of an electrode that is used as holding capacitor 405, form the 3rd impurity range 176 and second impurity range 177.Holding capacitor 405 is by passing through with dielectric film (film identical with gate insulating film) as medium, capacitor wiring 162 and semiconductor layer 106 formations.
Fig. 4 is the top view of this pixel parts 407.Fig. 4 is the top view of a pixel basically, adopts the identical reference marker with Fig. 3.And, along the cross section structure corresponding diagram 3 of line A-A ' and B-B '.In pixel structure shown in Figure 4, when forming grating routing and grid on different layers, grating routing and semiconductor layer can superpose.Like this, apply function to grating routing as optical screen film.And in order to shield gap between the pixel capacitors not by rayed, pixel capacitors is positioned to make its end and source wiring stack.Like this, obtain to omit the structure of optical screen film (black matrix).As a result, compare, improved aperture efficiency with conventional pixel parts.
[embodiment 2]
In this example, the step of making the Liquid crystal module of making by the active matrix substrate that obtains in embodiment 1 will be introduced.
On active matrix substrate shown in Figure 3, form oriented film, polish processing then.In this example, before forming oriented film, composition organic resin film such as acrylic resin film form column spacer in the precalculated position, so that keep substrate gaps.Replace column spacer, on the whole surface of substrate, disperse spherical sept.
Then, preparation opposed substrate.Form colour filter on opposed substrate, wherein the mode with corresponding each pixel provides band chromatograph and light shielding layer.In addition, on drive circuit, form light shielding layer.And, form the leveling film that covers colour filter and light shielding layer.Then, on the leveling film of pixel parts, form the opposite electrode of making by nesa coating at least.On the whole surface of opposed substrate, form oriented film, polish then.
With sealant will have formation thereon pixel parts and the active matrix substrate of drive circuit be fixed on the opposed substrate.Mixed filler in sealant.Two substrates are bonded to mutually together, keep uniform gap with filler and column spacer therebetween simultaneously.After this, between substrate, inject liquid crystal material, and seal fully with sealant.As liquid crystal material, can adopt known liquid crystal material.Then, as mentioned above, finish Liquid crystal module.In addition, when needing, active matrix substrate or opposed substrate are divided into needed shape.In addition, adopt the bonding polarising sheet of known method etc.Then, adopt fixedly FPC of known method.
The structure of the Liquid crystal module that obtains in this way below with reference to the top view introduction of Fig. 5.
Shown in the top view of Fig. 5, the active matrix substrate is fixed on the opposed substrate 200 with sealant 207.The active matrix substrate provides the wiring 210 that pixel parts, drive circuit, FPC (flexible print circuit) 211 are fixed external input terminals 209 on it and external input terminals be connected to the importation of each circuit.Opposed substrate 200 provides colour filter etc.
Provide the light shielding layer 203 that superposes with grid side drive circuit 201a in the opposed substrate side, the light shielding layer 803b that superposes with source drive circuit 201b is provided in the opposed substrate side.Provide the colour filter 202 on the pixel parts 205 that is arranged on the opposed substrate as follows: corresponding each pixel of band chromatograph of light shielding layer and every kind of color (red (R), green (G) and blue (B)).In fact, carrying out colour with three kinds of colors of the band chromatograph of the band chromatograph of the band chromatograph of red (R), green (G) and indigo plant (B) shows.Versicolor band chromatograph is arranged arbitrarily.
Here, show, colour filter 202 is provided on opposed substrate in order to carry out colour.But, the invention is not restricted in this.When making the active matrix substrate, can on the active matrix substrate, form colour filter.
In colour filter, light shielding layer is provided in the zone between the adjacent image point, stops light thus in the zone except the viewing area.In addition, provide light shielding layer 203a and the 203b that covers drive circuit.Yet, when liquid crystal indicator is installed in the electronic equipment as the display part, on the zone of drive circuit, place lid.Therefore, the zone of drive circuit covers without light shielding layer.In addition, when making the active matrix substrate, can on the active matrix substrate, form light shielding layer.
In addition, can also be following such.Replace above-mentioned light shielding layer is provided, a plurality of stacked band chromatograph that constitutes colour filter suitably is set between opposed substrate and opposite electrode, in the zone except viewing area and drive circuit (gap between each pixel capacitors), stop light thus.
In addition, will bond on external input terminals by the FPC 211 that basilar memebrane and wiring constitute with anisotropic conductive resin.In addition, strengthen the mechanical strength of this device with the reinforcement plate.
The Liquid crystal module made from aforesaid mode can be used for the display part of various electronic equipments.
[embodiment 3]
After forming interlayer dielectric, form the pixel capacitors of making by conducting film with light transmittance according to embodiment 1.As conducting film, can adopt ITO (tin indium oxide alloy), indium zinc oxide alloy (In with light transmittance
2O
3ZnO), zinc oxide (ZnO) etc.
Afterwards, in interlayer dielectric, form contact hole.Then, form the connection electrode of stack pixel capacitors.Connection electrode is connected to the drain region by contact hole.In addition, also form source electrode or the drain electrode of another TFT simultaneously with connection electrode.
Here, show all drive circuits wherein and all be formed on embodiment on the substrate.Yet several ICs can be used in a part of drive circuit.
Form active matrix substrate as mentioned above like that.Adopt the active matrix substrate to make Liquid crystal module, and bias light 310 and light guide plate 311 are provided, cover piece 312 is set then, finish the active array type LCD shown in Fig. 6 thus according to embodiment 2.Cover piece 312 and Liquid crystal module bond together mutually with bonding agent or organic resin.In addition, can be by between framework and substrate, filling organic resin so that, substrate is fixed on the opposed substrate around framework.Because this device is a transmission-type, so polarising sheet 309 is fixed on active matrix substrate and the opposed substrate.
[embodiment 4]
Under the situation of the n channel-type TFT shown in the embodiment 1, add the element (preferred phosphorus) of 15 families that belong to periodic table in can the semiconductor in channel formation region or belong to the element (preferred boron) of 13 families of periodic table, so that optionally make enhancement mode and depletion type.
Forming under the situation of nmos circuit, form the combination (being hereinafter referred to as " EEMOS circuit ") of enhancement mode TFTs or the combination (being hereinafter referred to as " EDMOS circuit ") of depletion type and enhancement mode TFTs by combination n channel TFT s.
Fig. 7 A represents the example of EEMOS circuit, and Fig. 7 B represents the example of EDMOS circuit.Each parts 31 and 32 shown in Fig. 7 A are enhancement mode n channel TFT (hereinafter referred to as " E type NTFT ").Parts 33 shown in Fig. 7 B are E type NTFT, the 34th, and depletion type n channel TFT (hereinafter referred to as " D type NTFT ").
In Fig. 7 A and 7B, V
DHExpression applies the power line (positive power line) of positive voltage, V
DLExpression applies the power line (negative power line) of negative voltage.Negative power line can be earth potential power line (ground power line).
Fig. 8 represents to adopt the example of the circuit-formed shift register of EDMOS shown in the EEMOS circuit shown in Fig. 7 A or Fig. 7 B.The part 40 and 41 of Fig. 8 is circuits for triggering.Parts 42 and 43 are E type NTFTs.The grid of clock signal (CL) input E type NTFT 42, the clock signal of opposite polarity (CL) is input to the grid of E type NTFT 43.Label by 44 expressions is a negative circuit.For forming this negative circuit, adopt EEMOS shown in Fig. 7 A or the EDMOS shown in Fig. 7 B, shown in Fig. 8 B.Therefore, all drive circuits of display device can constitute with n channel-type TFT.
Present embodiment can with any one combination of embodiment 1-3.
[embodiment 5]
In this example, the pixel structure (IPS system) that is different from embodiment 1 is shown among Fig. 9, and cross section structure is shown among Figure 10.Show the sectional view of line A-A ' and the sectional view of line H-H '.
This example has been showed the active matrix liquid crystal display device of IPS (in-plane switching) system (also being called the transverse electric field system).The IPS system is characterised in that pixel capacitors and public wiring all are formed on the substrate, and is laterally applying electric field.The control orientation is so that the axis alignment of Liquid crystal module is arranged essentially parallel to the direction of substrate surface.When using the IPS system, can enlarge the visual angle.
In Fig. 9, reference marker 1101 expressions first semiconductor layer, 1102 and 1103 expressions, second semiconductor layer, 1104 expressions, first electrode, 1105 expressions, second electrode, 1106 expression source wirings, 1107 expression grating routings, the public wiring of 1108 and 1109 expressions, 1110 expression connection electrode, 1111 expression pixel capacitors.Notice that pixel capacitors can so be provided with public wiring: promptly produce the electric field parallel with substrate surface.And public wiring can be arranged to superpose with source wiring.Like this, improved the aperture efficiency of pixel parts.
In addition, as shown in figure 10, first electrode 1104, second electrode 1105 and source wiring 1106 are formed on the dielectric film that covers first semiconductor layer and second semiconductor layer simultaneously.And pixel capacitors 1111, connection electrode 1110, grating routing 1107 and public wiring 1109 are formed on the interlayer dielectric that covers source wiring simultaneously.
And first electrode is electrically connected with grating routing.Be used as grid with first electrode of first semiconductor layer stack.
In this example, show pixel capacitors with rectangular shape.But pixel capacitors and common electrode can form the angle electrode structure, and can further enlarge the visual angle.
In addition, holding capacitor is made of the dielectric film and second electrode of second semiconductor layer, covering second semiconductor layer.Second electrode is electrically connected with the grating routing of adjacent image point.In addition, in second semiconductor layer, add the impurity element that the n type is provided.
Note, in this example, in changing embodiment 1 during used mask graph, can obtain pixel structure by the step identical with embodiment 1.
Utilize embodiment 1 to obtain after the state shown in Fig. 9 and 10, utilize the method described in the embodiment 2 to obtain liquid crystal device.As the situation of embodiment 2, utilize the gap between the colour filter light shield pixel that is provided in the opposed substrate.Note,, therefore need to change directional process etc. owing to used the IPS system.
[embodiment 6]
In this example, about the TFT of the drive circuit that in embodiment 1, obtains (channel length: L/ channel width: W=10 μ m/8 μ m), show and the length of the orientation of the impurity range (also being called the Lov district) of grid stack and the relation between the reliability.
Here, supposing that the length in the Lov district is under the situation of predetermined length, is the life-span of TFT up to the maximum (μ FE (max)) of the mobility of TFT with 10% time that changes.Then, the reverse quantity of drain voltage is plotted on the semilog plot, on the linear dependence basis that obtains from this curve, the value of drain voltage is introduced as 10 years safe voltages when the life-span is 10 years.
In this example, when the length (also being called Lov length) in the orientation in Lov district is set at 0.5 μ m, 0.78 μ m, 1.5 μ m and 1.7 μ m, suppose that the conducting electric current up to TFT is the life-span of TFT with 10% time that changes.Then, the reverse quantity of drain electrode is plotted on the semilog plot, and on the linear dependence basis that obtains from this curve, the value of drain voltage is introduced as 10 years safe voltages when the life-span is 10 years.What so obtain the results are shown among Figure 15.
Notice that under the time up to the conducting current value change 10% of TFT the time became 20 hours situation, the value of suppose drain electrode was 20 years safe voltages, tests the result who obtains by instantaneous stress and also is shown among Figure 15.
As shown in figure 15, when hypothesis was used in the 16V system device and consider 20% surplus, under the situation of 20 years safe voltages, the Lov section length of wishing to have 19.2V (16 * 1.2) or higher n channel TFT was 1 μ m or longer.And, under the situation of 10 years safe voltages, wish that this length is 1.5 μ m or longer.
[embodiment 7]
In this example, manufacturing comprises that the example of the luminescent device of organic luminescent device (OLED) is shown among Figure 16 A and the 16B.
Figure 16 A is the assembly top view with OLED, so-called EL assembly, and Figure 16 B is the sectional view that obtains by along line A-A ' intercepting Figure 16.Have formation pixel parts 902, source drive circuit 901 and grid side drive circuit 903 on the substrate of insulating surface (for example, glass substrate, glass ceramics substrate, plastic etc.) 900.Pixel parts and drive circuit can obtain according to the foregoing description 1.
And, reference marker 918 expression seal members, the diaphragm that 919 expressions are made of aluminum oxynitride, aluminium nitride or DLC film.Pixel parts and driving circuit section cover with seal member 918, and seal member 918 usefulness diaphragms 919 cover.In addition, pixel parts and driving circuit section adopt bonding agent to cover with cover piece 920.Cover piece 920 can be to be made by any blending agent, as plastics, glass, metal or pottery.And the shape of cover piece 920 and the shape of support be restriction especially not, and these parts can comprise shape with flat surfaces or the shape with curved surface.And these parts can be flexible.In addition, these parts can also form membranaceous.In order to resist because the distortion that heat, external force etc. produce, wish to have with substrate 900 for example the parts of glass substrate same material be used as cover piece 920.In this example, cover piece is to be processed into recess shapes (degree of depth is 3 μ m-10 μ m) shown in Figure 16 B by methods such as the methods of sandblasting.In addition, wish to handle the recess (degree of depth is 50 μ m-200 μ m) that formation can make drier 921 location.When making the EL assembly by repeatedly cut sth. askew (multiple beveling), bonding substrate and cover piece adopt CO then
2Lasers etc. are aimed at the end face cutting.
In addition, though it is not shown here, the background reflectance that causes in order to prevent because from the light reflection of the metal level that uses (negative electrode etc.) here can provide the circular polarization device of the so-called circular polarization plate of being made by phase difference plate (λ/4 plates) and polarising sheet on substrate 900.
Notice that reference marker 908 expressions are used to carry the wiring lines that is input to source drive circuit 901 and grid side drive circuit 903.This wiring is from FPC (flexible print circuit) 909 receiving video signals and clock signal as external input terminals.And this routine luminescent device can or can be worked with analog-driven with digital drive work.Vision signal can seem digital signal, perhaps can be analog signal.Notice that though FPC only is shown, printed wiring board (PWB) can bond on the FPC here.Luminescent device in this specification not only comprises the luminescent device main body, and comprises that FPC or PWB fix the luminescent device on it.And complicated integrated circuit (memory, CPU, controller, D/A converter etc.) can form with pixel parts on same substrate.Yet, be difficult to adopt a small amount of mask to make them.Like this, preferably the IC chip that comprises memory, CPU, controller, D/A converter etc. is installed by COG (glass top chip) method, TAB (tape automated bonding) method or wire bond method.
Then, adopt Figure 16 B to introduce cross-sectional structure.Dielectric film 910 is provided on the substrate 900.Pixel parts 902 and grid side drive circuit 903 are formed on the dielectric film 910.Pixel parts 902 is made of with a plurality of pixels that comprise the pixel capacitors 912 that is connected with its electric leakage Current Control TFT 911.In fact, in a pixel, form a plurality of TFTs.Yet, be concise explanation, Current Control TFT 911 only is shown here.Grid side drive circuit 903 is made of n channel TFT s 913 and 914.
These TFTs (comprising TFTs 911,913 and 914) can make according to the n channel TFT in the foregoing description 1.
And, about having the display device of OLED, following several method is arranged: have and wherein apply constant voltage so that carry the driving method of the circuit design of electric current to its to OLED, have and wherein apply constant current so that control the driving method of the circuit design of the voltage that puts on OLED to OLED, have the driving method of wherein giving the circuit design of OLED delivered constant electric current, or the like.But no matter driving method how, the brightness of pixel is by being electrically connected with OLED and to the conducting electric current (I of the TFT (in this specification, this TFT is called the Current Control TFT 911 among Current Control TFT and the corresponding diagram 16B) of OLED conveying electric current
On) determine.
Notice that in this example, n channel TFT s is used as switching TFT and Current Control TFT 911.But, the invention is not restricted to this structure.The quantity of the TFTs that provides in pixel can be 3,4,5,6 or more a plurality of.Switching TFT and Current Control TFT can be made of p channel TFT s.Note, when the negative electrode of OLED is used as pixel capacitors, wish that Current Control TFT is the n channel TFT.And, when the anode of OLED is used as pixel capacitors, wish that Current Control TFT is the p channel TFT.
And the dielectric film of wishing to have high flatness and high light transmittance is used as the active layer that is provided at TFT and the dielectric film between the OLED.Particularly, preferably respectively by coating (application) method and sputtering method stack organic resin film and silicon nitride film.Perhaps, preferably after forming dielectric film, flatten processing.Be used to improve the known technology of flatness, the polishing step that for example is called as chemical-mechanical polishing (hereinafter referred to as CMP) can be used as leveling and handles.When using CMP, for example, wherein the silica granule of being fuming that obtains by thermal decomposition silicon chloride gas is distributed to the polishing agent (slurry) that polishing agent in the aqueous solution that adds KOH preferably is used as the CMP that dielectric film is carried out.By CMP dielectric film is removed about 0.1 μ m-0.5 μ m, so that the leveling surface.About OLED, when the membrane thickness unevenness of organic compound layer, produce uneven light emission.Therefore, wish that thickness is even as much as possible.
Be used to stop the diffusion of foreign ion such as alkali metal ion or alkaline-earth metal ions and really the material of absorption impurity ion such as alkali metal ion or alkaline-earth metal ions preferably as being provided at the active layer of TFT and the dielectric film between the OLED.In addition, the material of the treatment temperature in the anti-later step is fit to.As the examples of material that is suitable for this condition, the silicon nitride film that contains a large amount of fluorine is arranged.The concentration of the fluorine that contains in the silicon nitride film is 1 * 10
19/ cm
3Or higher, preferred, the composition ratio that is included in the fluorine in the silicon nitride film is set at 1%-5%.The fluorine bond that is included in the silicon nitride film is incorporated on alkali metal ion, the alkaline-earth metal ions etc., and is absorbed in the film.And, as another example, the organic resin film that contains the particle that is made of antimony (Sb) compound, tin (Sn) compound or indium compound being arranged, it absorbs alkali metal ion, alkaline-earth metal ions etc., for example contains antimony pentaoxide particle (Sb
2O
5NH
2O) organic resin film.Notice that this organic resin film contains average grain diameter to be the particle of 10nm-20nm and to have very high light transmission features.Antimonial by the representative of antimony pentaoxide particle is easy to the absorption impurity ion, as alkali metal ion, alkaline-earth metal ions etc.
And, by AlN
xO
yThe layer of expression can be used as the active layer that is provided at TFT and another material of the dielectric film between the OLED.For example adopt that aluminium nitride (AlN) target carries out sputtering method, form the oxynitride layer that contains aluminium that obtains (by AlN by the film in the atmosphere of having mixed argon gas, nitrogen and oxygen therein
xO
yThe expression the layer be the film that contains the nitrogen of 2.5 atom %-47.5 atom %.Except the effect that can stop moisture and oxygen, the feature of this film also is high-termal conductivity, thermal radiation effect and high light transmission features.In addition, can prevent that impurity such as alkali metal or alkaline-earth metal from entering the active layer of TFT.
The pixel capacitors 912 that is electrically connected with electrode 809 is used as the anode of OLED, and wherein electrode 809 is electrically connected with the impurity range 806 of Current Control TFT 911.Have big work function conducting film, be generally conductive oxide film and be used as anode.Indium oxide, tin oxide, zinc oxide or its mixture preferably are used as conductive oxide film.Two ends in pixel capacitors 912 form the dike 915 that is made of inorganic insulator or organic insulator.On pixel capacitors 912, form EL layer 916 and the negative electrode 917 of OLED.
EL layer 916 (being used to produce the layer of light emission and mobile charge carrier) preferably forms by independent assortment luminescent layer, charge transport layer and electric charge injection layer.For example, preferred low molecular system organic EL Material or the polymeric system organic EL Material of adopting.And, can be used as the EL layer by the film that excites luminescent material (substance compound) formation that produces light emission (fluorescence) by substance or by the film that constitutes by triple luminescent materials (triple modular redundant compound) that excite generation light to launch (phosphorescence).And organic material such as carborundum can be used as charge transport layer or electric charge injection layer.Well known materials can be used as organic EL Material and inorganic EL material.
Negative electrode 917 also is used as the wiring that is common to all pixels, and is electrically connected with FPC909 by connecting wiring 908.Preferably adopt metal (metallic element that usually, belongs to 1 family or 2 families of periodic table) with little work function or the alloy that contains these metals to make the material of negative electrode 917.Because along with work function reduces, luminous efficiency improves, the alloy material of therefore wishing to contain as alkali-metal a kind of Li (lithium) is used as cathode material.In addition, all elements that are included in pixel parts 902 and the grid side drive circuit 903 all use negative electrode 917, seal member 918 and diaphragm 919 to cover.
Noting, is that transparent or translucent material is used for seal member 918 to visible light preferably.And, wish not allow the material of moisture and oxygen transmission to be used for seal member 918.
And, after covering OLOED fully, shown in Figure 16 B, preferably on the surface of seal member 918 (exposed surface), provide at least by being selected from by AlNO film, AlN film, Al with seal member 918
2O
3The diaphragm 919 that the individual layer of the group that film and DLC film constitute or lamination constitute.And, can provide diaphragm comprising on the whole surface of substrate back.Here, it will be noted that and in the part that external input terminals (FPC) is provided, do not form diaphragm.Handle, so that utilize mask to form diaphragm.And, handle, do not form diaphragm so that cover the external input terminals part by the adhesive tape that utilizes as be used in the mask adhesive tape in the CVD equipment.
Utilize said structure, when with seal member 918 and diaphragm 919 sealing OLED, OLED fully and external isolation and can prevent that oxidation owing to the EL layer from promoting the material of degenerating such as water or oxygen to enter from the outside.In addition, when being used as diaphragm, the heat that produces when driving OLED can spread when the film with thermal conductivity (AlON, AlN, etc.).Therefore, can obtain to have the luminescent device of high reliability.
In addition, can adopt wherein pixel capacitors to be used as negative electrode and EL layer and anode is superimposed as in the direction opposite with the situation of Figure 16 B and produces photoemissive structure.An example is shown among Figure 17.Notice, since identical, top view therefore omitted here.
To introduce the cross-sectional structure shown in Figure 17 below.Except glass substrate and quartz substrate, Semiconductor substrate or metal substrate also can be used as substrate 1000.Dielectric film 1010 is provided on the substrate 1000.Pixel parts 1002 and grid side drive circuit 1003 are formed on the dielectric film 1010.Pixel parts 1002 is made of with a plurality of pixels that comprise the pixel capacitors 1012 that is connected with the electric leakage of Current Control TFT 1011 Current Control TFT 1011.And grid side drive circuit 1003 is constituted by n channel TFT s 1013 and 1014.
Be that transparent or translucent material is used for seal member 1018 preferably to visible light.And, wish that the material that does not allow moisture and oxygen to see through as far as possible is used for seal member 1018.
And, under the situation of Figure 17, because pixel capacitors is used as negative electrode, and EL layer and anode stack, therefore photoemissive direction becomes by the direction shown in the arrow among Figure 17.
In addition, though it is not shown here, in order to prevent owing to, can on cover piece 1020, provide the circular polarization device that is called by the circular polarization plate of phase difference plate (λ/4) and polarising sheet formation from the metal level that uses (here for becoming the pixel capacitors of the negative electrode etc.) background reflectance that reverberation causes.
This example can with embodiment 1,4 and 6 independent assortments.
Drive circuit can be made of the shift register described in the embodiment 4.Yet, the situation that the decoder that will utilize Figure 18-20 introduction use to be made of n channel TFT s below replaces shift register and whole source drive circuit and whole grid side drive circuit to be made of E type TFTs.
Figure 18 represents the example of grid side drive circuit.In Figure 18, the decoder of reference marker 400 expression grid side drive circuit, the buffer portion of 401 expression grid side drive circuit.Notice that the term buffer portion refers to the part of wherein integrated a plurality of buffers (buffer amplifier).And the term buffer refers to and is used for prestage not being provided the circuit that drives under the situation of influence in rearmounted level.
At first, will introduce grid side decoder 400.The input signal cable (hereinafter referred to as selection wire) of reference marker 402 expression decoders 400.Here show A1, A1 (signal that obtains on the contrary by the polarity that makes A1), A2, A2 (signal that obtains on the contrary by the polarity that makes A2) ..., An, and An (signal that obtains on the contrary by the polarity that makes An).That is, can think arrangement " 2n " selection wire.
The quantity of selection wire is determined by the quantity of the row of the grating routing of exporting from the grid side drive circuit.For example, when being provided for the pixel parts of VGA demonstration, the quantity of grating routing is 480.Like this, under the situation of 9 (corresponding n=9), need to use 18 selection wires.Selection wire 402 is transmitted in the signal of representing in the sequential chart shown in Figure 19.As shown in figure 19, when the frequency that makes A1 was 1, the frequency of A2 was 2
-1Doubly, the frequency of A3 is 2
-2Doubly, the frequency of An is 2
-(n-1)Doubly.
And reference marker 403a represents first order NAND circuit (also being called the NAND unit), and 403b represents second level NAND circuit, and 403c represents n level NAND circuit.Require the quantity of the corresponding grating routing of quantity of NAND circuit, and need " n " individual NAND circuit here.In other words, according to the present invention, decoder 400 is made of a plurality of NAND circuit.
And NAND 403a-403c is combined by n channel TFT s 404-409.Notice that in fact, 2n TFTs is used for NAND circuit 403.Each grid of N channel TFT s 404-409 and selection wire 402 (A1, A1, A2, A2 ..., An is with An) any be connected.
At this moment, in NAND circuit 403a, have with any one A1, A2 ... the n channel TFT s 404-406 of the grid that are connected with An (these are called as positive selection wire) is connected in parallel mutually, and with negative power line (V as common source
DL) 410 connect, also be connected with output line 71 as data drain.And, have with any one A1, A2 ... the n channel TFT s 407-409 of the grid that are connected with An (these are called as negative selection wire) is connected in series mutually.Be positioned at the source and the positive power line (V of the n channel TFT 409 of circuit end
DH) 412 connections.The leakage that is positioned at the n channel TFT 407 of another circuit end is connected with output line 411.
As mentioned above, according to the present invention, " n " individual n channel TFT s that the NAND circuit comprises " n " the individual n channel TFT s that is connected in series and is connected in parallel.Notice that about " n " individual NAND circuit 403a-403c, the combination of n channel TFT s and selection wire differs from one another.That is, it is constituted as so that only select an output line 411, and is used to select the signal of output line 411 to be imported into selection wire 402 according to the order from an end.
Then, buffer portion 401 is made of a plurality of buffer 413a-413c of corresponding NAND circuit 403a-403c respectively.Notice that buffer 413a-413c can adopt same structure.
And buffer 413a-413c is made of n channel TFT s 414-416.Be transfused to grid from the output line 411 of decoder as n channel TFT 414 (a n channel TFT).About n channel TFT 414, provide positive power line (V
DH)417 as the source, provides the grating routing 418 of guiding pixel parts into as leaking.About n channel TFT 415 (the 2nd n channel TFT), provide positive power line (V
DH) 417 as grid, provide negative power line (V
DL) 419 as the source, and provide grating routing 418 as leaking.TFT 415 always is in conducting state.
That is, in the present invention, buffer 413a-413c comprise a n channel TFT (n channel TFT 414) and be connected in series with a n channel TFT and wherein the leakage of a n channel TFT be used as the 2nd n channel TFT (n channel TFT 415) of grid.
And, about n channel TFT 416 (the 3rd n channel TFT), provide reseting signal line (Reset) as grid, negative power line (V is provided
DL) 419 as the source, provide grating routing 418 as leaking.Note negative power line (V
DL) 419 can provide as ground power line (GND).
At this moment, the pass between the channel width (being represented by W2) of channel width of n channel TFT 415 (being represented by W1) and n channel TFT 415 is: W1＜W2.Notice that channel width is in the length perpendicular to the channel formation region of orientation.
The operation of buffer 413a is as follows.At first, when negative voltage put on output line 411, n channel TFT 414 became cut-off state (not producing the state of raceway groove).On the other hand, because n channel TFT 415 always is in conducting state (producing the state of raceway groove), so the voltage of negative power line 419 puts on grating routing 418.
Yet when positive voltage put on output line 411, n channel TFT 414 became conducting state.At this moment, because big than n channel TFT 415 of the channel width of n channel TFT 414, so the current potential of grating routing 418 is subjected to the influence of the output of n channel TFT 414.The result is that the voltage of positive power line 417 puts on grating routing 418.
Like this, when positive voltage puts on output line 411, grating routing 418 output positive voltages (the n channel TFT that is used as the switch element of pixel becomes the voltage of conducting state).On the other hand, when negative voltage put on output line 411, grating routing 418 was always exported negative voltage (the n channel TFT that is used as the switch element of pixel becomes the voltage of cut-off state).
Notice that n channel TFT 416 is used as the reset switch that the voltage that is used to force to apply the grating routing 418 of positive voltage is reduced to negative voltage.That is, the selection cycle of grating routing 418 was after the past, and the input reset signal applies negative voltage to give grating routing 418.Attention n channel TFT 416 can be omitted.
Utilize the grid side drive circuit of aforesaid operations to select grating routing.Then, the structure of source drive circuit is shown among Figure 20.Source drive circuit shown in Figure 20 comprises decoder 421, latch 422 and buffering part 423.Notice that decoder 421 has the structure identical with the grid side drive circuit with buffering part 423, has omitted its explanation here.
Under the situation of source drive circuit shown in Figure 20, latch 422 is made of first order latch 424 and second level latch 425.And first order latch 424 and second level latch 425 respectively have a plurality of unit 427 that are made of " m " individual n channel TFT s 426a-426c.Be input to the grid of " m " the individual n channel TFT s426a-426c that constitutes unit 427 from the output line 428 of decoder 421.
For example, under the situation that VGA shows, the quantity of source wiring is 640.When " m "=1, need 640 NAND circuit and 20 selection wires (corresponding 10).Yet when " m "=8, the quantity of the NAND circuit that needs is 80, and the quantity of the selection wire that needs is 14 (corresponding 7).That is, when the quantity of source wiring was " M ", the quantity of needed NAND circuit was (M/m).
Then, the source of n channel TFT s 426a-426c and each video signal cable (V1, V2 ..., Vk) 429 connect.That is, when applying positive voltage for output line 428, n channel TFT s 426a-426c becomes conducting state simultaneously, so that catch the corresponding video signal therein.In addition, among the capacitor 430a-430c that so the video captured signal is kept at respectively with n channel TFT s 426a-426c is connected.
And second level latch 425 has a plurality of unit 427b.Unit 427b is made of " m " individual n channel TFT s 431a-431c.All grid of n channel TFT s 431a-431c all are connected with latch signal line 432.When negative voltage put on latch signal line 432, n channel TFT s 431a-431c became conducting state simultaneously.
The result is, is kept among the capacitor 433a-433c that signal among the capacitor 430a-430c is stored in respectively with n channel TFT s 431a-431c is connected and the content that will preserve outputs to buffer portion 423.Then, as described in Figure 20, signal is outputed to source wiring 434 by buffer portion.By the source drive circuit of operating as mentioned above, select source wiring in order.
Like this, when grid side drive circuit and source drive circuit only were made of n channel TFT s, whole pixel parts and whole drive circuit can be made of n channel TFT s.Note,, also can realize the present invention even source drive circuit or grid side drive circuit are used as exterior I C chip.
[embodiment 8]
When adopting when implementing drive circuit that the present invention forms and pixel parts, can finish various assemblies (active matrix liquid crystal assembly, active matrix EL assembly and active matrix EC assembly).That is, can finish by implementing the present invention in conjunction with all electronic equipments of these assemblies.
As this electronic equipment, have video frequency camera, digital camera, head install display (goggle-type display), auto-navigation system, projecting apparatus, Car Stereo equipment, personal computer, portable data assistance (portable computer, mobile phone, electronic memo etc.), or the like.Figure 11 A-11C and Figure 12 A-12B represent the example of electronic equipment.
Figure 11 A represents personal computer, comprise that main body 2001, image input section divide 2002, display part 2003 and keyboard 2004,
Figure 11 B represents portable computer (portable computer), comprises main body 2201, camera part 2202, visual receiving unit 2203, console switch 2204 and display part 2205.
Figure 11 C represents to use the wherein player of the recording medium of logging program (hereinafter referred to as recording medium).This player comprises main body 2401, display part 2402, speaker portion 2403, recording medium 2404, console switch 2405 etc.Notice that about this player, DVD (digital universal disc), CD etc. are used as recording medium, can realize Music Appreciation, film appreciation, recreation and Internet.
Figure 12 A represents portable notebook (electronic memo), comprises main body 3001, display part 3002 and 3003, recording medium 3004, console switch 3005, antenna 3006 etc.
Figure 12 B represents display, comprises main body 3101, support 3102, display part 3103 etc.According to the present invention, can finish and have 10 inches-50 inches cornerwise displays.
As mentioned above, range of application of the present invention is extremely wide, and the present invention can be applied to the method for making the electronic equipment in all spectra.And, even can under situation about adopting, realize electronic equipment in this example by any structure that constitutes of embodiment 1-7.
According to the present invention, even when the area of pixel parts increases and obtain the large scale phosphor screen thus in the semiconductor device that with active matrix liquid crystal display device or active matrix light emitting device with OLED is representative, can realize best image.Owing to greatly reduce the resistance of the source wiring of pixel parts, so the present invention can also be applied to have for example 40 inches or 50 inches cornerwise large scale phosphor screens.
Claims (25)
1, a kind of semiconductor device that comprises a plurality of thin-film transistors, each thin-film transistor comprises:
Be formed on the semiconductor layer on the insulating surface;
Be formed on the dielectric film on the described semiconductor layer;
Be formed on the gate electrode on the described dielectric film; With
Be formed on the source wiring on the described dielectric film;
Wherein the source wiring of pixel portion comprises first conducting film that is formed on the described dielectric film and the laminated construction that is formed on second conducting film on described first conducting film and is formed on the 3rd conducting film on described second conducting film;
Wherein said first conducting film comprises at least one that is selected among Ta, W, Ti, Al, Cu and the Mo; With
The source wiring of wherein said gate electrode and described pixel portion has pyramidal structure.
2, according to the device of claim 1, wherein said second conducting film comprises at least one that is selected among Ta, W, Ti, Al, Cu and the Mo.
3, according to the device of claim 1, wherein said second conducting film comprises the alloy of Al and Ti.
4, according to the device of claim 1, wherein said second conducting film comprises the alloy of Al and Si.
5. according to the device of claim 1, wherein said the 3rd conducting film comprises at least one that is selected among Ta, W, Ti, Al, Cu and the Mo.
6, according to the device of claim 1, wherein said the 3rd conducting film comprises the nitride of the alloy that contains Ti.
7, according to the device of claim 1, wherein said source wiring forms by a part, the part of described second conducting film and the part of described the 3rd conducting film of described first conducting film of etching in the plasma of induction coupling.
8. according to the device of claim 1, wherein said source wiring forms by the conducting film identical with described gate electrode carried out composition.
9, according to the device of claim 1, wherein this semiconductor device is the Liquid crystal module of one of transmission-type and reflection-type.
10, according to the device of claim 1, wherein this semiconductor device is the luminescent device with OLED.
11, according to the device of claim 1, wherein this semiconductor device is one that is selected from the group that is made of video frequency camera, digital camera, auto-navigation system, personal computer, portable data assistance and electronic game computer.
12. a method of making semiconductor device comprises:
On insulating surface, form semiconductor layer;
On described semiconductor layer, form dielectric film;
On described dielectric film, form the laminated construction of first conducting film, second conducting film and the 3rd conducting film;
Part by the part of described first conducting film of etching in the plasma of induction coupling, described second conducting film and the part of described the 3rd conducting film and on described dielectric film, form the source wiring of pixel portion;
Be electrically connected described source wiring and described semiconductor layer;
Wherein said source wiring is film formed by described first conducting film, described second conducting film and described the 3rd conduction; With
Wherein the source wiring of gate electrode and described pixel portion has pyramidal structure.
13, according to the method for the manufacturing semiconductor device of claim 12, wherein said semiconductor layer comprises crystalline silicon.
14. according to the method for the manufacturing semiconductor device of claim 12, wherein said gate electrode forms in the step identical with source wiring.
15. according to the method for the manufacturing semiconductor device of claim 14, wherein said gate electrode comprises at least one that is selected among Ta, W, Ti, Al, Cu and the Mo.
16. according to the method for the manufacturing semiconductor device of claim 12, wherein said laminated construction comprises lamination, W film and Al film and the lamination of TiN film or the lamination of TaN film and Al film and Ti film of W film and Al film and TiN film.
17. according to the method for the manufacturing semiconductor device of claim 12, wherein said first conducting film comprises the nitride that contains the Ta alloy.
18. according to the method for the manufacturing semiconductor device of claim 12, wherein said first conducting film comprises W.
19. according to the method for the manufacturing semiconductor device of claim 12, wherein said second conducting film comprises the alloy of Al and Ti.
20. according to the method for the manufacturing semiconductor device of claim 12, wherein said second conducting film comprises the alloy of Al and Si.
21. according to the method for the manufacturing semiconductor device of claim 12, wherein said the 3rd conducting film comprises the nitride that contains the Ti alloy.
22. according to the method for the manufacturing semiconductor device of claim 12, wherein said etching is at BCl
3And Cl
2Mist in carry out.
23. according to the method for the manufacturing semiconductor device of claim 12, wherein said etching is at BCl
3, Cl
2And O
2Mist in carry out.
24. according to the method for the manufacturing semiconductor device of claim 12, wherein said etching is at CF
4, Cl
2And O
2Mist in carry out.
25. according to the method for the manufacturing semiconductor device of claim 12, wherein this semiconductor device is one that is selected from the group of being made up of player, digital camera and the projecting apparatus of personal computer, video frequency camera, portable computer, head mounted display, use storage medium.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001056063 | 2001-02-28 | ||
| JP56063/01 | 2001-02-28 | ||
| JP302687/01 | 2001-09-28 |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB021065594A Division CN1311558C (en) | 2001-02-28 | 2002-02-28 | Semiconductor device and mfg. method thereof |
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| Publication Number | Publication Date |
|---|---|
| CN101026172A CN101026172A (en) | 2007-08-29 |
| CN100474595C true CN100474595C (en) | 2009-04-01 |
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| CNB2007100858101A Expired - Lifetime CN100474595C (en) | 2001-02-28 | 2002-02-28 | Semiconductor device |
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| CN103686005A (en) * | 2013-12-24 | 2014-03-26 | 北京交通大学 | Pixel unit circuit with memory and multiple selection output functions |
| CN110462843B (en) * | 2017-04-06 | 2023-07-07 | 夏普株式会社 | TFT substrate and scanning antenna provided with same |
| CN116525577B (en) * | 2023-07-03 | 2023-11-28 | 合肥晶合集成电路股份有限公司 | Semiconductor structure and manufacturing method thereof |
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