JPH1154763A - Semiconductor device, light valve device, and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable extremely high pixel density, by using a substrate having at least multiple structure composed of an insulating carrier layer and a silicon semiconductor single crystal thin film layer formed on it. SOLUTION: For example, a light valve device is composed of a driving substrate 1, an opposite substrate 8 arranged in opposition to the driving substrate 1, and electro-optical substance layers, for example, a liquid crystal layer 9 arranged between the driving substrate 1 and the opposite substrate 8. The driving substrate 1 has an at least double-layer structure composed of a carrier layer 2 made out of quartz glass, and a single crystalline silicon semiconductor film layer 3 having a crystal orientation of <100> 0.0±1.0 deg.. A driving circuit is composed of an integrated circuit formed in this single crystal silicon semiconductor film layer 3. And each pixel electrode 12 formed in the pixel regions 5 integrated circuit chips 4 acts on the liquid crystal layer 9 excited selectively by the conduction of a transistor element connected to the electrode, controls its light transmitting property, and functions as a light valve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat light valve device used for a direct-view display device, a projection display device and the like.
More specifically, the present invention relates to a light valve device, for example, an active matrix device in which an integrated circuit substrate having a drive circuit formed on a semiconductor thin film is integrally incorporated as a liquid crystal panel.

[0002]

2. Description of the Related Art The principle of an active matrix device is extremely simple. A switching element is provided for each pixel, and when a specific pixel is selected, the corresponding switching element is turned on. It is to be in a conductive state. This switch element is formed on a glass substrate constituting a liquid crystal panel. Therefore, the technology for thinning the switch element is important. Usually, a thin film transistor is used as this element.

Conventionally, in an active matrix device, a thin film transistor has been formed on the surface of an amorphous silicon thin film or a polycrystalline silicon thin film deposited on a glass substrate. Since these amorphous silicon thin films and polycrystalline silicon thin films can be easily deposited on a glass substrate by using a chemical vapor deposition method, they are suitable for manufacturing an active matrix device having a relatively large screen. A transistor element formed on an amorphous or polycrystalline silicon thin film is generally of a field effect insulated gate type. At present, an active matrix liquid crystal device using an amorphous silicon thin film having an area of about 3 to 10 inches is commercially produced. Since the amorphous silicon thin film can be formed at a low temperature of 250 ° C. or less, it is suitable for a large-area liquid crystal panel. The polycrystalline silicon thin film is formed at a temperature of about 600 ° C., and a small liquid crystal panel of about 2 inches is currently commercially produced in an active matrix liquid crystal device using the thin film.

[0004]

A conventional active matrix device using an amorphous silicon thin film or a polycrystalline silicon thin film is suitable for a direct-view type display device requiring a relatively large area image surface. However, it is not necessarily suitable for miniaturization and high density of pixels. In recent years, there has been an increasing demand for microminiature display devices or light valve devices having miniaturized high-density pixels, separately from direct-view display devices. Such a micro light valve device is used, for example, as a primary image forming surface of a projection type image device, and can be applied as a projection type high vision television. By using the fine semiconductor manufacturing technology, it becomes possible to provide an ultra-small light valve device having a pixel size of the order of 1 μm and a size of about several cm as a whole. However, when a conventional amorphous or polycrystalline silicon thin film is used, even if it is miniaturized, amorphous has little advantage in terms of operation speed and polycrystal has little advantage in terms of variation in characteristics. For example, in the case of an amorphous silicon thin film, the mobility is only about 1/100 of that of a single crystal, which is not advantageous for miniaturization and high speed.
Also, in the case of a polycrystalline silicon thin film, the size of crystal grains had to be about μm in order to increase the carrier mobility, so that the characteristics were inevitably increased by miniaturizing the thin film element. It will vary. As described above, in an active matrix display device using a conventional amorphous or polycrystalline silicon thin film, it is extremely difficult to achieve the same integration density and information transmission speed as a normal semiconductor integrated circuit device. There was a problem that it is.

[0005] In view of the above-mentioned problems of the prior art, it is a first object of the present invention to provide a light valve device such as a miniaturized active matrix liquid crystal device. In order to achieve this object, in the present invention, a thin film switching element is formed using a substrate having a multilayer structure composed of an electrically insulating carrier layer and a silicon semiconductor single crystal thin film layer formed thereon. .

Incidentally, various types of semiconductor laminated substrates having such a multilayer structure have been conventionally known. This is a so-called SOI substrate. The SOI substrate has a single-crystal structure in which, for example, a polycrystalline silicon thin film is deposited on a carrier surface made of an insulating material by a chemical vapor deposition method or the like, and then subjected to heat treatment by laser beam irradiation or the like to recrystallize the polycrystalline film. Was obtained by converting to However, in general, a single crystal obtained by recrystallization of a polycrystal does not always have a uniform crystal orientation and has a large lattice defect density. For these reasons, it has been difficult to apply a miniaturization technique to an SOI substrate manufactured by a conventional method, similarly to a silicon single crystal wafer, and to integrate many uniform characteristics. In view of this point, the present invention uses a silicon semiconductor single crystal thin film having crystal orientation uniformity and low-density lattice defects similar to that of a silicon single crystal wafer widely used in a semiconductor manufacturing process. It is a second object to provide a light valve device with high resolution.

[0007]

Means taken to achieve the above first and second objects will be described with reference to FIG. FIG. 1A shows a plan shape of a substrate 1 used in the present invention, and FIG. 1B shows a cross-sectional structure in the same manner. As shown, the substrate 1 has, for example, a wafer shape with a diameter of 6 inches. The substrate 1 includes a carrier layer 2 made of, for example, quartz, and a single crystal thin film layer 3 made of, for example, silicon formed thereon.
And a two-layer structure (generally a multilayer structure as described later). A miniaturized semiconductor manufacturing technique is applied to the single crystal thin film layer 3 of the substrate 1 to form, for example, a drive circuit and a pixel electrode of an active matrix device for each chip section.

FIG. 1C is an enlarged plan view of the integrated circuit chip thus obtained. As shown, the integrated circuit chip 4 has a length of, for example, 1.5 cm per piece, and is significantly smaller than a conventional active matrix device. The integrated circuit chip 4 has a pixel region 5 in which fine pixel electrodes arranged in a matrix and insulated gate field-effect transistors corresponding to individual pixel electrodes are formed.
A driver circuit for supplying an image signal to each transistor, that is, an X driver region 6 in which an X driver is formed.
And a scanning circuit for scanning each transistor element line-sequentially, that is, a Y driver area 7 in which a Y driver is formed. According to the present invention, a single crystal thin film having a carrier ("carrier" in Japanese) charge mobility that is extremely large as compared with an amorphous thin film or a polycrystalline thin film is used. Can be formed on the same plane as the pixel region.

FIG. 1D is a sectional view showing an ultra-small and ultra-high-density active matrix type light valve device assembled using the above-described integrated circuit chip 4. As shown
The light valve device includes an opposing substrate 8 disposed opposite to the integrated circuit chip 4 with a predetermined gap therebetween, and an electro-optical material layer, for example, a liquid crystal layer 9 filled in the gap. The surface of the integrated circuit chip 4 is covered with an alignment film 10 for aligning liquid crystal molecules contained in the liquid crystal layer 9. Integrated circuit chip 4
The individual pixel electrodes formed in the pixel region 5 are selectively excited by the conduction of the transistor element to which they are connected, act on the liquid crystal layer 9, control the light transmission characteristics thereof, and function as light valves. Since each pixel electrode is larger than the thickness of the spacer and the size can be reduced to about several μm, an extremely high-definition active matrix liquid crystal device can be obtained.

FIG. 1E is a partially enlarged plan view of the pixel region 5 shown in FIG. 1C, and shows one pixel. FIG. 1E is a schematic sectional view of one pixel. As shown in the figure, a pixel 11 is connected to a pixel electrode 12, a pixel electrode 12, a transistor 13 for exciting the pixel electrode 12 according to a signal, a signal line 14 for supplying a signal to the transistor 13, and the transistor And a scanning line 15 for scanning 13. The signal line 14 is connected to the X driver, and the scanning line 15 is connected to the Y driver 7. Transistor
Reference numeral 13 denotes a drain region, a source region formed in the single crystal thin film layer 3, a channel region formed therebetween, and a gate electrode 16 formed on the channel region via a gate insulating film. I have. That is, the transistor 13 is an insulated gate field effect type. The gate electrode 16 is composed of a part of the scanning line 15, the source region is connected to the pixel electrode 12, and the drain region is connected to the drain electrode 17. The drain electrode 17 forms a part of the signal line 14.

As described above, according to the present invention, a substrate having at least a multilayer structure composed of an insulating carrier layer and a silicon semiconductor single crystal thin film layer formed thereon is used. The single crystal thin film layer has the same quality as a wafer made of a silicon semiconductor single crystal bulk. Therefore, a pixel electrode, a switching element for driving the pixel, and the like can be integratedly formed on the silicon semiconductor single crystal thin film layer by making full use of the miniaturization technology.
The resulting integrated circuit chip has a very high pixel density and a very small pixel size, and can constitute a microminiature high-definition light valve device such as an active matrix liquid crystal device.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 is a schematic exploded perspective view showing one embodiment of the light valve device according to the present invention. As shown in the figure, the light valve device includes a driving substrate 1, an opposing substrate 8 disposed opposite to the driving substrate, the driving substrate 1 and the opposing substrate 8.
And an electro-optical material layer, for example, a liquid crystal layer 9 disposed therebetween. On the drive substrate 1, a pixel electrode or a drive electrode 12 for defining a pixel and a drive circuit for exciting the drive electrode 12 according to a predetermined signal are formed. The drive substrate 1 has at least a two-layer structure including a carrier layer 2 made of quartz glass and a single-crystal silicon semiconductor film layer 3. In addition, a polarizing plate 18 is provided on the back side of the quartz glass carrier layer 2.
Is glued. The drive circuit is formed of an integrated circuit formed on the single crystal silicon semiconductor film layer 3. This integrated circuit includes a plurality of field effect insulated gate transistors 13 arranged in a matrix. Transistor
The source electrode 13 is connected to the corresponding pixel electrode 12, the gate electrode is also connected to the scanning line, and the drain electrode is also connected to the signal line 14 if the drain electrode. The integrated circuit further includes an X driver 6 and is connected to a column-shaped signal line 14. Further, the Y-driver 7 includes a row of scanning lines 15.
It is connected to the. Further, the opposing substrate 8 has a glass carrier 19,
A polarizing plate 20 adhered to the outer surface of the glass carrier 19, and a counter electrode or a common electrode formed on the inner surface of the glass carrier 19.
21. Although the single crystal silicon semiconductor thin film is drawn uniformly in the drawing, it is actually in a state where a part thereof is left as shown in FIG.

FIG. 3 is a schematic perspective view showing one pixel of the light valve device shown in FIG. 2 cut out, and FIG.
11 shows a case where the pixel 11 is in a non-selected state, and FIG. 3B shows a case where the pixel 11 is in a selected state. In this embodiment, a nematic liquid crystal material is used for the liquid crystal layer 9. Nematic liquid crystal molecules have the property that the major axis direction is easily aligned. The alignment of the liquid crystal molecules is determined by the driving substrate 1 and the counter substrate 8.
Is obtained by performing a rubbing treatment on the inner side surface of the. As shown, the rubbing direction is 90
゜ Because they are different, the liquid crystal molecules also rotate by 90 °.
As a result, the polarization axis of the light passing through the liquid crystal layer 9 is rotated by 90 °. On the other hand, as shown in FIG. 3 (B), when an electric field is applied between the pixel electrode formed on the surface of the driving substrate 1 and the counter electrode formed on the inner surface of the counter substrate 8, the liquid crystal molecules Arranged in the direction, that is, perpendicular to the substrate, the optical rotation is lost. This transition is optically detected by a pair of polarizing plates 18 and 20 arranged above and below the liquid crystal layer. That is, light passing through the liquid crystal layer is transmitted or cut off depending on whether or not a voltage is applied. Thus, the light valve device according to the present invention has a light valve function for each pixel.

FIG. 4 is a graph showing the relationship between the voltage applied to the liquid crystal constituting the pixel shown in FIG. 3 and the transmittance of the liquid crystal layer. As shown in the figure, when a voltage equal to or higher than the threshold voltage (4 V) is applied between the counter electrode and the pixel electrode, the transmittance of the liquid crystal layer changes extremely, and the liquid crystal layer shifts from the shielding state to the transmission state. The voltage applied to the pixel is controlled by controlling conduction of a transistor element connected to the pixel electrode.

Next, the operation of the above-described embodiment will be described in detail with reference to FIGS. Individual transistor elements
The gate electrode 13 is connected to the scanning line 15, and a scanning signal is applied by the Y driver 7 to control the conduction and cutoff of the individual transistor elements 13 line by line. X driver 6
Is applied to a selected transistor 13 which is in a conductive state via a signal line 14. The applied display signal is transmitted to the corresponding pixel electrode 12, excites the pixel electrode and acts on the liquid crystal layer 9 to substantially reduce the transmittance thereof to 100%.
%. On the other hand, when not selected, the transistor element 13 is turned off, and the display signal written to the pixel electrode is maintained as electric charge. The liquid crystal layer 9 has a high specific resistance and normally operates as a capacitive element. To indicate the switching performance of these drive transistor elements 13,
An off-current ratio is used. The current ratio required for the liquid crystal operation can be easily obtained from the writing time and the holding time. For example, if the display signal is a television signal, 90% or more of the display signal must be written during about 60 .mu.sec of the -scan line period. On the other hand, 90% or more of the electric charge must be held in one field period of about 16 msec. As a result, the current ratio needs to be 5 digits or more. At this time, since the driving transistor element is formed on the single crystal silicon semiconductor film layer 3 having extremely high carrier mobility, an on / off ratio of 6 digits or more can be secured. Accordingly, it is possible to obtain an active matrix type light valve device having an extremely high-speed signal response. Further, the peripheral driver circuits 6 and 7 can be formed on the silicon single crystal semiconductor thin film on the same substrate at the same time by utilizing the high mobility characteristics of the single crystal thin film.

Next, with reference to FIGS. 5 and 6, a method of manufacturing a semiconductor chip type light valve device substrate on which pixel electrodes and drive circuits are integrated will be described in detail. First, in the step shown in FIG. 5A, a quartz glass substrate 2 and a single crystal silicon semiconductor substrate 22 are prepared. Single crystal silicon semiconductor substrate 22
It is preferable to use a high quality silicon wafer used for LSI manufacturing, and its crystal orientation is <100> 0.0
It has a uniformity in the range of ± 1.0, and has a single crystal lattice defect density of 500 defects / cm 2 or less. First, the surface of the prepared quartz glass substrate 2 and the surface of the single crystal silicon semiconductor substrate 22 are precisely smoothed. Then, both substrates are thermally bonded by overlapping and heating both surfaces which have been smoothed. By this heat bonding process, both substrates 2 and 22 are firmly fixed to each other.

In the step shown in FIG. 5B, the surface of the single crystal silicon semiconductor substrate is polished. As a result, a single-crystal silicon semiconductor film layer 3 polished to a desired thickness is formed on the surface of the quartz glass substrate 2. A driving substrate 1 having a two-layer structure composed of a carrier layer 2 made of a quartz glass substrate and a single crystal silicon semiconductor film layer 3 is obtained. Note that an etching process may be used instead of the polishing process to make the single crystal silicon semiconductor substrate 22 thinner. In the single-crystal silicon semiconductor film layer 3 thus obtained, the quality of the silicon wafer 22 is substantially preserved as it is, so that it is possible to obtain a substrate material with excellent crystal orientation uniformity and lattice defect density. . On the other hand, as has conventionally been done, a single crystal thin film obtained by recrystallization of a deposited amorphous or polycrystalline silicon thin film has many lattice defects and non-uniform crystal orientation, so that the Not suitable for

In the step shown in FIG. 5C, the surface of the single crystal silicon semiconductor film layer 3 is thermally oxidized to form a silicon oxide film 23 on the entire surface. A silicon nitride film 24 is deposited thereon using a chemical vapor deposition method. Further, a resist 25 is coated. The resist 25 is patterned by photolithography, and is removed leaving only the element region 26. In this state, an etching process is performed to remove portions of the silicon oxide film 23 and the silicon nitride film 24 that are not covered with the resist 25. FIG. 5C shows the processing state of the driving substrate 1 thus obtained.

In the step shown in FIG.
After removing the silicon oxide film 23 covering the element region 26
Then, using the silicon nitride film 24 as a mask, the single crystal silicon semiconductor film layer 3 is subjected to thermal oxidation to form a field oxide film 27. The single crystal silicon film layer 3 is left in a region surrounded by the field oxide film 27 to form an element region 26. In this state, the silicon oxide film 23 and the silicon nitride film 24 used as the mask have been removed.

In the step shown in FIG. 6E, a thermal oxidation process is performed again, and a gate oxide film 28 is formed on the surface of the single crystal silicon film layer 3. In the step shown in FIG. 6F, a polycrystalline silicon film is deposited by a chemical vapor deposition method. This polycrystalline silicon film is selectively etched using a resist 29 patterned into a predetermined shape to form a gate oxide film.
A gate electrode 16 made of a polycrystalline silicon film is formed on.

In the step shown in FIG.
After removing 9, ions of impurity arsenic are implanted through gate oxide film 28 using gate electrode 16 as a mask to form drain region 30 and source region 31 in silicon single crystal film 3. As a result, a transistor channel forming region 32 into which impurity arsenic is not implanted is provided between the drain region 30 and the source region 31 below the gate electrode 16.

Finally, in the step shown in FIG. 6H, a part of the gate oxide film 28 on the drain region 30 is removed to form a contact hole, and the drain electrode 17 is connected thereto. Similarly, a part of the gate oxide film 28 on the source region 31 is removed to form a contact hole, and the drive electrode 12 is formed so as to cover this part. The drive electrode or pixel electrode 12 is composed of a transparent electrode made of ITO or the like. In addition, the field oxide film 27 disposed below the pixel electrode 12 is transparent, and the quartz glass substrate 2 disposed therebelow is also transparent. Therefore, the three-layer structure including the drive electrode 12, the field oxide film 27, and the quartz glass substrate 2 is optically transparent, so that a transmission type light valve device can be obtained.

As described above, in the manufacturing method shown in FIGS. 5 and 6, a high-quality single-crystal silicon film is subjected to a film forming process, a high-resolution photolitho-etching process, an ion implantation process, and the like using the prior art. By applying this, it is possible to form a field-effect insulated gate transistor having a size on the order of microns or submicrons. Since the silicon single crystal film used is of extremely high quality, the obtained insulated gate transistor has excellent electrical characteristics. At the same time, since the pixel electrodes can be formed in the order of microns on the basis of the miniaturization technology, a semiconductor integrated circuit chip substrate for an active matrix liquid crystal device having a high-density and fine structure can be manufactured.

FIG. 7 is a schematic sectional view showing another embodiment of the semiconductor integrated circuit chip for a light valve device according to the present invention.
As shown, the integrated circuit chip has a pixel region 5 and driver regions 6 and 7 on a substrate 2. Pixel area 5
A pixel electrode (not shown) and an insulated gate transistor element 13 connected to the pixel electrode are formed. The transistor 13 includes a source region 30 and a drain region 31 formed in the silicon single crystal film 3 and a gate electrode 16 disposed on the silicon single crystal film via a gate insulating film. The region where the transistor 13 is formed is surrounded by the field oxide film 27.

On the other hand, the driver regions 6 and 7 are arranged at positions separated from the pixel region 5, and have an insulated gate transistor 13a as a component thereof. The transistor 13a includes a source region 30a and a drain region 31a formed in the common silicon single crystal film 3, and a gate electrode 16a disposed via a gate insulating film. The region where the transistor 13a is formed is similarly surrounded by the field oxide film 27a. As is clear from the figure, the insulated gate transistor 13 in the pixel region 5 and the insulated gate transistor 13a in the driver regions 6 and 7 can be simultaneously formed on the common silicon single crystal film 3.

Incidentally, in a light transmission type light valve device,
The transmission and blocking of light incident on the pixel region 5 are controlled.
Therefore, the pixel region 5 must be transparent to the incident light, and therefore, the silicon single crystal film 3 is completely thermally oxidized and converted into the field oxide film 27. That is, the field oxide film 27 made of silicon dioxide is transparent,
The single crystal silicon film 3 left only in the element region is opaque. On the other hand, it is preferable that the driver regions 6 and 7 are not related to the light valve function and are shielded from incident light as much as possible. Insulated gate transistor due to the effect of incident light
This is because the normal operation of 13a is hindered. Therefore, in the embodiment shown in FIG. 7, the field oxide film 27a formed in the driver regions 6 and 7 is obtained by partially thermally oxidizing only the upper portion of the silicon single crystal film 3, and the field oxide film 27a The silicon single crystal film 3 is left under the film 27a. As described above, since the silicon single crystal film 3 is opaque, incident light can be effectively blocked.

FIG. 8 is a graph showing the relationship between drain current and drain voltage of an insulated gate transistor formed on a silicon single crystal film. The solid line shows the case where a constant potential is applied to the channel formation region, and the dotted line shows the case where the semiconductor is opened below the channel formation region. As is clear from the figure,
When a constant potential is applied to the channel formation region and the potential is stabilized, a stable operation of the transistor which can obtain an ideal drain current saturation characteristic with respect to the drain voltage can be secured. On the other hand, when the channel formation region is open, the potential is unstable, so that the drain current fluctuates with respect to the drain voltage. Therefore, FIG.
In the embodiment shown in FIG. 7, the channel forming region can be given a constant potential through the silicon thin film left under the field oxide film 27a. As described above, according to the preferred embodiment of the present invention, a silicon single crystal film is obtained by polishing, so that a desired film thickness can be secured and a silicon thin film for applying a constant potential to a channel formation region can be left. . The fixing of the potential may be performed only on the insulated gate transistor formed in the driver region, or may be performed on the transistor formed in both the driver region and the pixel region.

FIG. 9 is a graph showing the relationship between the drain leakage current of an insulated gate transistor formed on a silicon single crystal film and the thickness of the silicon single crystal film. The drain leak current indicates a magnitude of a leak current flowing in a channel region when a drain voltage is applied to a transistor in a non-conductive state. As shown in the figure, when the incident light is not irradiated, the dependency of the drain leak current on the thickness of the silicon single crystal layer is small. However, when the incident light of, for example, 3000 lux is irradiated, the drain leak current increases as the film thickness increases. The drain leak current deteriorates the on / off current ratio of the transistor, and therefore needs to be suppressed as much as possible. In particular, since a transistor formed in a pixel region receives irradiation of incident light, a countermeasure is required. Therefore, it is preferable that the thickness of the silicon single crystal layer existing in the pixel region is set smaller than the thickness of the silicon single crystal layer existing in the driver region. From FIG. 9, the thickness of the silicon single crystal layer existing in the pixel region is
It is preferable to make it 1000 mm or less. Control of the film thickness can be easily performed by selective etching or the like. Especially,
It is practically important that the silicon single crystal layer has a larger drain leak current when irradiated with light than a silicon amorphous layer or a silicon polycrystal layer.

FIG. 10 is a schematic sectional view showing another embodiment of the integrated circuit chip substrate according to the present invention.
Shows a cross section of a raw material substrate, and FIG. 10B is a cross section of a completed product in which an insulated gate transistor is formed on the raw material substrate. The raw material substrate is a quartz carrier layer 2 and a single crystal silicon film layer 3
Has a three-layer structure in which a low resistance film layer 33 is interposed in the middle of the laminated structure. The low resistance thin film layer 33 is made of, for example, a polycrystalline silicon thin film doped with impurities. In manufacturing, first, a low-resistance thin film layer 33 is deposited on the quartz carrier layer 2, and a single-crystal silicon wafer is thermally bonded thereon. Then, the single-crystal silicon film layer 3 having a desired film thickness can be obtained by polishing the single-crystal silicon wafer.

Single crystal silicon film layer 3 and low resistance thin film layer 33
An insulated gate transistor is formed on the two-layer structure film by the same method as the steps shown in FIGS.
This transistor has a source region 30 and a drain region 31 formed in a single crystal silicon film layer, a channel region 32 formed therebetween, and a gate disposed on the channel region 32 with a gate oxide film 28 interposed therebetween. And an electrode 16. This element region is surrounded by a field oxide film 27. Below the channel region 32 is a low resistance region 34. This low resistance region 34 is obtained from the low resistance thin film layer 33. With such a structure, the potential of the channel formation region of the insulated gate transistor can be set, and the operation is stabilized.

FIG. 11 is a schematic sectional view showing another embodiment of the active matrix type light valve device according to the present invention. This light valve device is configured using an integrated circuit chip substrate 4. As described above, the integrated circuit chip substrate 4 incorporates driving circuit elements such as pixel electrodes and switching transistors that are miniaturized with respect to the silicon single crystal thin film layer. A spacer 35 is further formed on the surface of the integrated circuit chip substrate 4. The spacer 35 is formed on the surface of the integrated circuit chip substrate 4 by a film forming technique and a fine patterning technique used in semiconductor manufacturing. Therefore, the thickness of the spacer 35 can be controlled very accurately. For example, the film thickness is set to 10 μm when using a nematic liquid crystal, and 1 μm when using a ferroelectric liquid crystal.
m. A counter substrate 8 is arranged on the integrated circuit chip substrate 4 with a spacer 35 interposed therebetween. Then, a liquid crystal layer 9 is filled in a gap defined between the substrates by the thickness of the spacer 35. Finally, a polarizing plate 18 is bonded to the outer surface of the integrated circuit chip substrate 4, and another polarizing plate 20 is bonded to the outer surface of the counter substrate 8 in the same manner. The pair of polarizing plates 18 and 20 are for optically detecting a change in the molecular arrangement of the liquid crystal layer 9.

FIG. 12 is a schematic plan view showing still another embodiment of the integrated circuit chip substrate for a light valve according to the present invention. This integrated circuit chip 4 has a pixel area 5, an X driver area 6, and a Y driver area 7, as in the above-described embodiment. In addition, a video signal processing circuit area 36 is provided.
The video signal processing circuit formed in the area 36 processes an image signal or a video signal input from an external signal source and transfers the processed signal to the X driver area 6. As described above, since a silicon single crystal thin film is used in the present invention, a video signal processing circuit is simultaneously formed in a semiconductor fine processing in addition to a pixel electrode driving transistor and a signal circuit or a scanning circuit formed in a driver region. It can be formed using technology. That is, it is possible to freely incorporate an additional circuit having an LSI-scale function on the integrated circuit chip substrate 4. When a light valve device or a display device is formed by using the integrated circuit chip 4 shown in FIG. 12, it can be directly connected to an external image signal source, so that a small-sized image device with excellent versatility can be obtained. Can be. Examples of the circuits additionally incorporated include, for example, a memory circuit, an IC inspection circuit, a sensor circuit, and the like in addition to the video signal processing circuit.

Finally, an application example of the active matrix light valve device according to the present invention will be briefly described with reference to the drawings.
FIG. 13 shows an example applied to a video projector. The video projector 37 has a built-in ultra-small light valve device constructed using the integrated circuit chip substrate shown in FIG. 12, and displays a primary image in accordance with a video signal on the light valve device, and displays the primary image on an enlarged optical system. , And a secondary image 38 of high magnification is projected and displayed on a screen.
The example shown is a small ceiling-hanging type. As described above, the active matrix type light valve device according to the present invention has an ultra-small size on the order of centimeters, so that the video projector itself can be extremely reduced in size as compared with the related art. Even though the dimensions of the light valve device are extremely small, the formed pixel area includes extremely high-density fine pixels, so that even when enlarged projection is performed, a so-called high-definition class high-quality secondary projection is performed. Images can be obtained.

FIG. 14 shows the video projector shown in FIG.
FIG. 37 is a schematic enlarged sectional view of 37. The video projector 37 incorporates three active matrix transmission type light valve devices 39 to 41. The white light emitted from the white light source lamp 42 is reflected by the reflecting mirror M1 and then separated into red light, blue light and green light by the three-color separation filter 43. The red light selectively reflected by the dichroic mirror DM1 is reflected by the reflecting mirror M2, and then reflected by the condenser lens C1.
And is incident on the first light valve device 39. The red light modulated by the light valve device 39 in accordance with the video signal passes through dichroic mirrors DM3 and DM4 and is enlarged and projected forward through an enlargement lens 44. Similarly, the blue light that has passed through the dichroic mirror DM1 is selectively reflected by the dichroic mirror DM2, is collected by the condenser lens C2, and then enters the second light valve device 40. Here, after being modulated according to the video signal, the light is incident on a common magnifying lens 44 via dichroic mirrors DM3 and DM4. After passing through the dichroic mirrors DM1 and DM2, the green light is condensed by the condenser lens C3 and is incident on the third light valve device 41. Here, after being modulated according to the video signal,
The light is reflected by the reflecting mirror M3 and the dichroic mirror DM4 and travels to the magnifying lens 44. In this way, the three primary color lights modulated by the three light valve devices are finally combined by the magnifying lens 44 to project a secondary image enlarged forward. The dimensions of the light valve device used are on the order of centimeters, and the dimensions of various optical components and white light lamps can be reduced in accordance with this dimension. Therefore, the overall shape and size of the video projector 37 can be significantly reduced as compared with the conventional one.

FIG. 15 shows the video projector shown in FIG.
It is a typical perspective view which shows the example which applied 37 to the projection CRT. In the projection CRT, a screen constituting a television screen is illuminated from behind by a video projector 37, and a secondary enlarged image 38 is projected on the television screen. Such a projection CRT has a very high resolution and a high brightness. Further, a completely flat screen can be formed, and the screen is extremely lightweight.

Finally, FIG. 16 is a schematic sectional view showing an application example in which a color display device is constituted by using the integrated circuit chip substrate according to the present invention. A plurality of pixel electrodes 12 are formed on the integrated circuit chip substrate 4. A glass opposing substrate 8 is overlaid on the integrated circuit chip substrate 4 with a predetermined gap therebetween. The gap between the two substrates is filled with a liquid crystal layer 9. Three primary color filters 45 are formed on the inner surface of the glass opposing substrate 8. Color filter 45 is a pixel electrode
It is subdivided corresponding to 12. An overcoat 46 is coated on the color filter 45. Further, the common electrode 21 is formed on the overcoat 46. With this configuration, the liquid crystal layer 9 is sandwiched between the common electrode 21 and the pixel electrode 12 and selectively driven by an electric field. Color filter 45
A dyeing method having high color purity and good pattern accuracy is used as a method for forming the dye. In this method, an organic substrate is selectively dyed by red, green and blue dyes by three times of photolithography.

Further, the integrated circuit chip substrate 4 is
Even if color filters of three primary colors are formed on the upper pixel electrode 12, a color display device can be achieved.

[0038]

As described above, according to the present invention, a pixel electrode and a drive circuit are integrally formed on a silicon semiconductor single crystal thin film layer formed on a carrier layer by using a semiconductor miniaturization technique. The light valve device is configured using the integrated circuit chip substrate obtained as described above. Therefore, there is an effect that a light valve device having an extremely high pixel density can be obtained.
In addition, since the dimensions of the integrated circuit chip substrate can be made approximately the same as those of a normal semiconductor IC chip, an extremely small light valve device can be obtained. Since the pixel is manufactured using the semiconductor miniaturization technology, there is an effect that an extremely accurate light valve device can be obtained. Since each element can be formed on the single crystal thin film layer by using the integrated circuit technology, there is an effect that circuits having various functions comparable to LSI can be easily added. Since the integrated circuit chip is obtained by dividing the wafer, a local defect on the wafer only makes a part of the chip defective. As a whole, the yield can be increased as compared with the related art, and the cost can be reduced. Further, since the single crystal thin film layer is used, there is an effect that a high temperature process can be applied and miniaturization of each circuit element can be promoted. Finally, using a single-crystal thin film, not only a switching transistor but also a driver circuit and its protection circuit can be incorporated at the same time, which has the effect of improving reliability.

[Brief description of the drawings]

1A is a plan view of a substrate, FIG. 1B is a schematic sectional view of the same substrate, FIG. 1C is an enlarged plan view of an integrated circuit chip formed on the substrate, and FIG. FIG. 3 is a schematic cross-sectional view of a light valve device used for a substrate, (E) is an enlarged plan view of a pixel formed in a pixel region of an integrated circuit chip, and (F) is a schematic enlarged cross-sectional view of the pixel region.

FIG. 2 is a schematic exploded perspective view showing one embodiment of the light valve device.

FIGS. 3A and 3B are schematic exploded perspective views showing the operation of each pixel.

FIG. 4 is a graph showing a relationship between a liquid crystal applied voltage and transmittance.

FIGS. 5A to 5D are process diagrams showing one embodiment of a method for manufacturing a semiconductor integrated circuit chip.

FIGS. 6E to 6H are process diagrams showing one embodiment of a method for manufacturing a semiconductor integrated circuit chip.

FIG. 7 is a schematic sectional view showing another embodiment of the semiconductor integrated circuit chip substrate.

FIG. 8 is a graph showing a relationship between a drain voltage and a drain current of an insulated gate transistor.

FIG. 9 is a graph showing the relationship between the drain leakage current of an insulated gate transistor formed in a silicon single crystal layer and the thickness of the silicon single crystal layer.

FIGS. 10A and 10B are schematic sectional views showing still another embodiment of the integrated circuit chip substrate.

FIG. 11 is a schematic sectional view showing another embodiment of the light valve device.

FIG. 12 is a schematic plan view showing still another embodiment of the integrated circuit chip substrate.

FIG. 13 is a schematic perspective view of a video projector to which the light valve device is applied.

FIG. 14 is a schematic sectional view showing a detailed structure of a video projector.

FIG. 15 is a schematic perspective view of a projection CRT incorporating a video projector.

FIG. 16 is a schematic sectional view showing an example in which an integrated circuit chip substrate is applied to a color active matrix display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Carrier layer 3 Silicon semiconductor single crystal thin film layer 4 Integrated circuit chip substrate 5 Pixel region 6 X driver 7 Y driver 8 Opposite substrate 9 Liquid crystal layer 11 Pixel 12 Pixel electrode 13 Transistor 14 Signal line 15 Scan line 16 Gate electrode 17 Drain Electrode 21 Common electrode 22 Single crystal silicon semiconductor substrate 26 Element region 27 Field oxide film 28 Gate oxide film 30 Drain region 31 Source region 32 Transistor channel formation region 33 Low resistance thin film layer 34 Low resistance region 35 Spacer 36 Video signal processing circuit region 37 Video projector 39 Light valve device 40 Light valve device 41 Light valve device 45 Color filter

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01L 27/12 H01L 29/78 612B (72) Inventor Masaaki Kamiya 1-8 Nakase, Mihama-ku, Chiba-shi, Chiba Seiko Instruments Inc. (72) Inventor Yoshikazu Kojima 1-8-8 Nakase, Mihama-ku, Chiba-shi, Chiba Seiko Instruments Inc. (72) Inventor Hiroaki Takasu 1-8-1, Nakase, Mihama-ku, Chiba-shi, Chiba Seiko Instruments Inc.

Claims (13)

[Claims] An integrated circuit including a plurality of driving elements arranged in a matrix, a pixel electrode electrically connected to the driving elements, and a driving circuit for selectively driving the driving elements is formed. In a light valve device including a driving substrate, an opposing substrate disposed opposite to the driving substrate, and an electro-optical material layer disposed between the driving substrate and the opposing substrate, the driving substrate includes a carrier layer and a <100> And a silicon semiconductor single crystal thin film layer having a crystal orientation of 0.0 ± 1.0 °. The integrated circuit further processes an externally input image signal and transfers the image signal to the drive circuit. Signal processing circuit, a memory circuit for storing the image signal, and a defect detection circuit for detecting a defect in the integrated circuit, wherein the integrated circuit is the silicon semiconductor single crystal thin film layer or the carrier layer To Is product placement, and the light valve device, characterized in that to control the optical transparency by acting on the electro-optical material layer when excited by said active element. 2. An integrated circuit comprising: a pixel region including a plurality of driving elements arranged in a matrix and pixel electrodes electrically connected to the driving elements; and a driving circuit for selectively supplying a signal to the driving elements. A driving substrate having a driving region formed of a circuit, a counter substrate disposed opposite to the driving substrate, and an electro-optical material layer disposed between the driving substrate and the counter substrate; In a light valve device for selectively controlling the optical characteristics of the electro-optical material, the driving substrate is a silicon semiconductor single crystal thin film having a crystal orientation of <100> 0.0 ± 1.0 ° disposed on a carrier layer. The integrated circuit is formed on the surface of the silicon semiconductor single-crystal thin film layer opposite to the carrier layer, the driving region is opaque, and the pixel region transmits light. Light valve device characterized by being transparent . 3. The integrated circuit includes an insulated gate transistor formed on a surface of the silicon semiconductor single crystal thin film layer and a field oxide film for electrically isolating the insulated gate transistor. 2. A light valve device according to claim 1, wherein a silicon semiconductor single crystal thin film is formed between said carrier layer and said carrier layer. 4. The active element includes an insulated gate transistor formed on a surface of the silicon semiconductor single crystal thin film layer opposite to the carrier layer, wherein the insulated gate transistor is a field oxide film in contact with the carrier layer. The light valve device according to claim 1, wherein the light valve device is electrically separated by: 5. The light valve device according to claim 1, wherein a constant potential is applied to said silicon semiconductor single crystal thin film. 6. The active element includes an insulated gate transistor formed on a surface of the silicon semiconductor single crystal thin film layer opposite to the carrier layer, wherein the silicon semiconductor single crystal thin film layer has a thickness exceeding 1000 °. The light valve device according to claim 1, wherein the light valve device is not provided. 7. The light valve device according to claim 1, wherein a low resistance thin film layer is formed between the silicon semiconductor single crystal thin film layer and the carrier layer. 8. An electro-optical device comprising a spacer fixed to a predetermined position of the driving substrate, a predetermined distance from the counter substrate, and a liquid crystal in a gap between the driving substrate and the counter substrate. The light valve device according to claim 1, wherein the light valve device is filled with a material layer. 9. The light valve device according to claim 1, wherein a subdivided color filter is formed on the counter substrate corresponding to the matrix pixel electrodes. 10. A projection device comprising a light source, a light valve device for selectively transmitting light from the light source to display an image, and a lens for enlarging the image, wherein the light valve device is arranged in a matrix. A driving substrate on which an integrated circuit including a plurality of driving elements arranged, a pixel electrode electrically connected to the driving element, and a driving circuit for selectively driving the driving element is formed; An opto-substrate disposed oppositely; an electro-optical material layer disposed between the driving substrate and the opposing substrate; the driving substrate includes a carrier layer;
Wherein the integrated circuit has a multilayer structure comprising at least a silicon semiconductor single crystal thin film layer having a crystal orientation of 00> 0.0 ± 1.0 ° not exceeding 1000 °. A projection device integrated on a carrier layer and, when excited by the drive circuit, acts on the electro-optical material layer to control its light transmittance. 11. A projection device comprising a light source, a light valve device for selectively transmitting light from the light source to display an image, and a lens for enlarging the image, wherein the light valve device is arranged in a matrix. A driving substrate on which an integrated circuit including a plurality of driving elements arranged, a pixel electrode electrically connected to the driving element, and a driving circuit for selectively driving the driving element is formed; An opto-substrate disposed oppositely; and an electro-optical material layer disposed between the driving substrate and the opposing substrate.
A multilayer structure comprising at least a silicon semiconductor single crystal thin film layer having a crystal orientation of 0 ± 1.0 °;
Further, at least one of an image signal processing circuit for processing an image signal input from the outside and transferring the image signal to the driving circuit, a memory circuit for storing the image signal, and a defect detection circuit for detecting a defect of the integrated circuit. Wherein the integrated circuit is integrated on the silicon semiconductor single crystal thin film layer or the carrier layer, and acts on the electro-optic material layer when excited by the active element to control its light transmittance. And projection equipment. 12. A projection device comprising a light source, a light valve device for selectively transmitting light from the light source to display an image, and a lens for enlarging the image, wherein the light valve device is arranged in a matrix. A pixel region including a plurality of arranged driving elements and a pixel electrode electrically connected to the driving element, and a driving region including an integrated circuit including a driving circuit for selectively supplying a signal to the driving element are formed. A driving substrate, an opposing substrate disposed opposite to the driving substrate, and an electro-optical material layer disposed between the driving substrate and the opposing substrate, wherein the active element controls the optical characteristics of the electro-optical material. The driving substrate has a multilayer structure including a silicon semiconductor single crystal thin film layer having a crystal orientation of <100> 0.0 ± 1.0 ° disposed on a carrier layer. , The silicon semiconductor single crystal Together with the integrated circuit is formed on the opposite surface to the carrier layer of the film layer, the driving area is opaque, the pixel area projection apparatus, characterized in that the transparent light. 13. The projection device according to claim 10, wherein the size of the light valve device is on the order of centimeters.