JP4872870B2 - Electro-optical device, method of manufacturing electro-optical device, and projection display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrooptical device capable of preventing specular reflection of returned light in a peripheral circuit region and emission of the returned light from an element substrate side, when the returned light is made incident on the element substrate, to provide a manufacturing method of the electrooptical device, and to provide a projection-type display device. <P>SOLUTION: In the electrooptical device 100, a plurality of light-scattering concavo-convex parts 10t (spherical concave parts 10v) are formed in the peripheral circuit region 10d of a light-transmissive substrate 10s used for the element substrate 10. Thereby, even when the returned light of modulated light is made incident, directed toward the peripheral circuit region 10d of the element substrate 10, the returned light is reflected at the spherical concave parts 10v to be scattered. Thus imaging of the peripheral circuit region 10d in an outer edge part of a projected image, caused by reflection of the returned light at the peripheral circuit region 10d, can be prevented. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an electro-optical device such as a liquid crystal device, a method for manufacturing the electro-optical device, and a projection display device including the electro-optical device.

  Among various electro-optical devices, in a liquid crystal device, a liquid crystal layer is held between an element substrate and a counter substrate, and light incident from the counter substrate side is modulated by the liquid crystal layer and emitted from the element substrate side. The element substrate includes a pixel region in which a plurality of pixels each including a pixel electrode and a pixel transistor are formed on a light-transmitting substrate, and a peripheral circuit region in which a plurality of wiring and driving circuit transistors are formed on the outer peripheral side of the pixel region. have. Such an electro-optical device is used as, for example, a light valve in a projection display device, and displays an image by enlarging and projecting modulated light onto a projection surface such as a screen by a projection optical system.

In such a projection display device, when the modulated light is reflected by a surface on the output side of the element substrate or an optical system disposed on the output side with respect to the electro-optical device, the reflected light is electro-optically used as return light. The light may enter from the element substrate side of the device, and when such return light enters the pixel transistor, it causes a light leakage current. Therefore, it has been proposed to form a light shielding layer on the lower side of the pixel transistor in the element substrate to prevent the occurrence of light leakage current (see, for example, Patent Documents 1 to 3).
JP 2004-342923 A JP 2000-131716 A JP 2000-298290 A

  However, in the element substrate of the electro-optical device, metal wiring and metal electrodes are arranged in a high density in the peripheral circuit area. Therefore, when the return light is incident on the peripheral circuit area, the return light that is regularly reflected in the peripheral circuit area is On the screen, as shown in FIG. 11, there is a problem that the reflection 320 of the peripheral circuit occurs along the outer edge of the projection image 310. Sufficient measures have not been taken.

  In view of the above problems, the object of the present invention is to prevent the return light from being regularly reflected in the peripheral circuit region and being emitted from the element substrate side again when the return light is incident on the element substrate. An electro-optical device, a method for manufacturing the electro-optical device, and a projection display device including the electro-optical device.

In order to solve the above problems, the present invention, the first surface side of the translucent substrate, a pixel region in which pixels having a pixel electrode and a pixel transistor is formed with a plurality of, outside of the pixel region, wiring and includes an element substrate having a peripheral circuit driving circuit transistor is formed with a plurality, in the electro-optical device for emitting light modulated from the second surface side opposite to the first surface of the light transmitting substrate, wherein the area overlapping with the peripheral circuit of the light-transmitting substrate, wherein the plurality of light scattering irregularities for scattering light incident from the second surface side of the translucent substrate are formed, the plurality of light-scattering The concave portion constituting the concave and convex portions for use is characterized in that the inner surface is covered with a light shielding layer .

  In the present invention, since a plurality of light scattering irregularities are formed in a region overlapping the peripheral circuit region in the light-transmitting substrate used as the element substrate, the modulated light is emitted from the surface on the emission side of the element substrate. Even when reflected from an optical system or the like disposed on the emission side with respect to the electro-optical device and incident as return light from the element substrate side, the return light is scattered by a plurality of light scattering irregularities. For this reason, since the return light is not regularly reflected from the peripheral circuit area and emitted from the element substrate, the peripheral circuit area is prevented from being reflected along the outer edge of the image displayed on the projection surface such as a screen. can do. In addition, when a solid light-shielding film is formed in a region that overlaps the peripheral circuit region in the light-transmitting substrate used as the element substrate, the presence of the light-shielding film follows the outer edge of the image displayed on the projection surface such as a screen. However, in the present invention, since the return light is scattered by the light scattering unevenness, such a problem does not occur.

  In the present invention, a configuration in which the inner surface is covered with a light-shielding layer can be adopted for the concave portions constituting the plurality of light scattering irregularities. With this configuration, even when part of the return light is reflected by the light shielding layer, it is reflected while being scattered, so that unnecessary reflection can be prevented.

  In the present invention, the concave portions constituting the plurality of light scattering irregularities have inner surfaces covered with a light shielding layer, and the plurality of concave portions are filled with a filling material formed so as to cover the light shielding layer. In addition, it is preferable that the formation region of the plurality of recesses is flattened in the translucent substrate by the filling material. With this configuration, even when part of the return light is reflected by the light shielding layer, it is reflected while being scattered, so that unnecessary reflection can be prevented. In addition, even when a peripheral circuit is formed on a region where light scattering unevenness is formed on the element substrate, the peripheral circuit can be formed in a region without a step due to the light scattering unevenness, and the reliability of the peripheral circuit is determined by the step. Etc. can be reliably prevented.

  In the present invention, the light shielding layer may be a semi-transmissive light shielding film capable of partially transmitting light. If comprised in this way, the reflected light quantity in the unevenness | corrugation for light scattering can be decreased.

  In the present invention, it is possible to adopt a configuration in which inner surfaces of the plurality of recesses constituting the plurality of light scattering irregularities are covered with a light-transmitting material having a refractive index different from that of the light-transmitting substrate. If comprised in this way, return light can be scattered by the refractive action in the unevenness | corrugation for light scattering.

  In this case, it is preferable that the inside of the recess is filled with the light-transmitting material, and the regions where the plurality of recesses are formed in the light-transmitting substrate are flattened by the light-transmitting material. With this configuration, even when the peripheral circuit is formed on the region where the light scattering unevenness is formed on the element substrate, the peripheral circuit can be formed in the region without the step due to the light scattering unevenness. It is possible to reliably prevent the circuit reliability from being lowered.

  In the present invention, the plurality of light scattering irregularities are constituted by, for example, a plurality of concave portions recessed in a spherical shape on the translucent substrate. If comprised in this way, return light can be scattered efficiently.

  In this invention, you may employ | adopt the structure by which the said several uneven | corrugated for light scattering is formed in the said translucent board | substrate by the some groove-shaped recessed part with circular arc shape in cross section. If comprised in this way, return light can be scattered efficiently.

  The electro-optical device according to the present invention is, for example, a liquid crystal device, and the liquid crystal device includes a counter substrate disposed to face the element substrate, and a liquid crystal layer is held between the counter substrate and the element substrate. ing.

An electro-optical device manufacturing method according to the present invention includes a pixel region in which a plurality of pixels each including a pixel electrode and a pixel transistor are formed on a first surface side of a translucent substrate, and a wiring and an outer side of the pixel region. Manufacturing an electro-optical device including an element substrate having a peripheral circuit on which a plurality of drive circuit transistors are formed, and emitting modulated light from a second surface side opposite to the first surface of the translucent substrate. in the method, a region which overlaps with the peripheral circuit of the light-transmitting substrate, in forming a plurality of light scattering irregularities for scattering light incident from the second surface side of the translucent substrate, the translucent A mask forming step of forming a mask having an aperture in a region to be a recess of the plurality of light scattering irregularities, and a recess for performing wet etching from the aperture to the light-transmitting substrate. Forming process; And performing.

  According to such a manufacturing method, as a result of the etching progressing isotropically in the recess forming step, it is possible to form a spherical recess or a groove-like recess having an arc cross section.

  The electro-optical device to which the present invention is applied is used in, for example, a projection display device, and the projection display device includes a projection optical system that projects light modulated by the electro-optical device.

  A projection display device using an electro-optical device (liquid crystal device) to which the invention is applied and the electro-optical device will be described with reference to the drawings. In the drawings to be referred to in the following description, the scales are different for each layer and each member so that each layer and each member have a size that can be recognized on the drawing.

[Configuration of Projection Display Device]
With reference to FIG. 1, a projection display device using an electro-optical device to which the present invention is applied as a light valve will be described. FIG. 1 is a schematic configuration diagram of a projection display device to which the present invention is applied.

  The projection display device 110 shown in FIG. 1 irradiates light on a screen 111 (projected surface) provided on the viewer side, and observes the light reflected by the screen 111. The projection display apparatus 110 includes a light source unit 140 including a light source 112, dichroic mirrors 113 and 114, a relay system 120, liquid crystal light valves 115 to 117, a cross dichroic prism 119 (combining optical system), and projection optics. System 118.

  The light source 112 is composed of an ultrahigh pressure mercury lamp that supplies light including red light, green light, and blue light. The dichroic mirror 113 is configured to transmit red light from the light source 112 and reflect green light and blue light. The dichroic mirror 114 is configured to transmit blue light and reflect green light among green light and blue light reflected by the dichroic mirror 113. Thus, the dichroic mirrors 113 and 114 constitute a color separation optical system that separates the light emitted from the light source 112 into red light, green light, and blue light.

  Between the dichroic mirror 113 and the light source 112, an integrator 121 and a polarization conversion element 122 are sequentially arranged from the light source 112. The integrator 121 is configured to make the illuminance distribution of the light emitted from the light source 112 uniform. Further, the polarization conversion element 122 is configured to change the light from the light source 112 into polarized light having a specific vibration direction such as s-polarized light.

  The liquid crystal light valve 115 is a transmissive electro-optical device (liquid crystal device) that modulates red light transmitted through the dichroic mirror 113 and reflected by the reflecting mirror 123 in accordance with an image signal. The liquid crystal light valve 115 includes a λ / 2 phase difference plate 115a, a first polarizing plate 115b, a liquid crystal panel 115c, and a second polarizing plate 115d. Here, the red light incident on the liquid crystal light valve 115 remains s-polarized light because the polarization of the light does not change even if it passes through the dichroic mirror 113. The λ / 2 phase difference plate 115a is an optical element that converts s-polarized light incident on the liquid crystal light valve 115 into p-polarized light. The first polarizing plate 115b is a polarizing plate that blocks s-polarized light and transmits p-polarized light. The liquid crystal panel 115c is configured to convert p-polarized light into s-polarized light (circularly polarized light or elliptically polarized light in the case of halftone) by modulation according to an image signal. Furthermore, the second polarizing plate 115d is a polarizing plate that blocks p-polarized light and transmits s-polarized light. Accordingly, the liquid crystal light valve 115 is configured to modulate the red light according to the image signal and emit the modulated red light toward the cross dichroic prism 119. The λ / 2 phase difference plate 115a and the first polarizing plate 115b are disposed in contact with a light-transmitting glass plate 115e that does not convert polarized light, and the λ / 2 phase difference plate 115a and the first polarizing plate 115b. It is possible to avoid distortion of 115b due to heat generation.

  The liquid crystal light valve 116 is a transmissive electro-optical device (liquid crystal device) that modulates green light reflected by the dichroic mirror 114 after being reflected by the dichroic mirror 113 in accordance with an image signal. Similar to the liquid crystal light valve 115, the liquid crystal light valve 116 includes a first polarizing plate 116b, a liquid crystal panel 116c, and a second polarizing plate 116d. Green light incident on the liquid crystal light valve 116 is s-polarized light that is reflected by the dichroic mirrors 113 and 114 and then incident. The first polarizing plate 116b is a polarizing plate that blocks p-polarized light and transmits s-polarized light. The liquid crystal panel 116c is configured to convert s-polarized light into p-polarized light (circularly polarized light or elliptically polarized light in the case of halftone) by modulation according to the image signal. The second polarizing plate 116d is a polarizing plate that blocks s-polarized light and transmits p-polarized light. Accordingly, the liquid crystal light valve 116 is configured to modulate green light in accordance with an image signal and emit the modulated green light toward the cross dichroic prism 119.

  The liquid crystal light valve 117 is a transmissive electro-optical device (liquid crystal device) that modulates blue light reflected by the dichroic mirror 113 and transmitted through the dichroic mirror 114 and then passed through the relay system 120 in accordance with an image signal. Similarly to the liquid crystal light valves 115 and 116, the liquid crystal light valve 117 includes a λ / 2 phase difference plate 117a, a first polarizing plate 117b, a liquid crystal panel 117c, and a second polarizing plate 117d. Here, since the blue light incident on the liquid crystal light valve 117 is reflected by the two reflecting mirrors 125a and 125b described later of the relay system 120 after being reflected by the dichroic mirror 113 and transmitted through the dichroic mirror 114, the s-polarized light is reflected. It has become. The λ / 2 phase difference plate 117a is an optical element that converts s-polarized light incident on the liquid crystal light valve 117 into p-polarized light. The first polarizing plate 117b is a polarizing plate that blocks s-polarized light and transmits p-polarized light. The liquid crystal panel 117c is configured to convert p-polarized light into s-polarized light (circularly polarized light or elliptically polarized light in the case of halftone) by modulation according to an image signal. The second polarizing plate 117d is a polarizing plate that blocks p-polarized light and transmits s-polarized light. Accordingly, the liquid crystal light valve 117 is configured to modulate the blue light according to the image signal and emit the modulated blue light toward the cross dichroic prism 119. The λ / 2 phase difference plate 117a and the first polarizing plate 117b are arranged in contact with the glass plate 117e.

  The relay system 120 includes relay lenses 124a and 124b and reflection mirrors 125a and 125b. The relay lenses 124a and 124b are provided to prevent light loss due to a long blue light path. Here, the relay lens 124a is disposed between the dichroic mirror 114 and the reflection mirror 125a. The relay lens 124b is disposed between the reflection mirrors 125a and 125b. The reflection mirror 125a is disposed so as to reflect the blue light transmitted through the dichroic mirror 114 and emitted from the relay lens 124a toward the relay lens 124b. The reflection mirror 125b is arranged to reflect the blue light emitted from the relay lens 124b toward the liquid crystal light valve 117.

  The cross dichroic prism 119 is a color combining optical system in which two dichroic films 119a and 119b are arranged orthogonally in an X shape. The dichroic film 119a is a film that reflects blue light and transmits green light, and the dichroic film 119b is a film that reflects red light and transmits green light. Therefore, the cross dichroic prism 119 is configured to combine the red light, the green light, and the blue light modulated by the liquid crystal light valves 115 to 117 and emit the resultant light toward the projection optical system 118.

  Note that light incident on the cross dichroic prism 119 from the liquid crystal light valves 115 and 117 is s-polarized light, and light incident on the cross dichroic prism 119 from the liquid crystal light valve 116 is p-polarized light. Thus, by making the light incident on the cross dichroic prism 119 different types of polarized light, the light incident from the liquid crystal light valves 115 to 117 in the cross dichroic prism 119 can be effectively combined. Here, in general, the dichroic films 119a and 119b are excellent in the reflection characteristics of s-polarized light. For this reason, red light and blue light reflected by the dichroic films 119a and 119b are s-polarized light, and green light transmitted through the dichroic films 119a and 119b is p-polarized light. The projection optical system 118 has a projection lens (not shown) and is configured to project the light combined by the cross dichroic prism 119 onto the screen 111.

  Hereinafter, the configuration of the liquid crystal panel used for the liquid crystal light valves 115 to 117 (electro-optical device / liquid crystal device) in the projection type display device shown in FIG. 1 will be described in detail. Note that the liquid crystal light valves 115 to 117 and the liquid crystal panels 115c to 117c shown in FIG. 1 differ only in the wavelength range of light to be modulated and have the same basic configuration, so that the liquid crystal light valves 115 to 117 are electro-optical devices. The liquid crystal panels 115c to 117c will be described as a liquid crystal panel 100p.

[Embodiment 1]
(Overall configuration of LCD panel)
FIG. 2 is a block diagram showing an electrical configuration of a liquid crystal panel used for a liquid crystal light valve (electro-optical device / liquid crystal device) in the projection type display device shown in FIG. FIGS. 3A, 3B, and 3C are plan views of the liquid crystal panel 100p of the electro-optical device 100 to which the present invention is applied as viewed from the counter substrate side along with the respective components, and the HH ′ cross section thereof. It is a figure and II 'sectional drawing.

  As shown in FIG. 2, the electro-optical device 100 includes a liquid crystal panel 100p, and the liquid crystal panel 100p includes a pixel region 10b in which a plurality of pixels 100a are arranged in a matrix in the central region. In the liquid crystal panel 100p, on the element substrate 10 described later, a plurality of data lines 6a and a plurality of scanning lines 3a extend vertically and horizontally inside the pixel region 10b, and the pixel 100a is located at a position corresponding to the intersection. Is configured. In each of the plurality of pixels 100a, a field effect transistor 30 as a pixel transistor and a pixel electrode 9a are formed. The data line 6 a is electrically connected to the source of the field effect transistor 30, the scanning line 3 a is electrically connected to the gate of the field effect transistor 30, and the pixel electrode 9 a is connected to the drain of the field effect transistor 30. Are electrically connected.

  In the element substrate 10, the outer region of the pixel region 10b is a peripheral circuit region 10d in which the scanning line driving circuit 104, the data line driving circuit 101, and the like are formed. The data line driving circuit 101 is electrically connected to one end of each data line 6a, and sequentially supplies the image signal supplied from the image processing circuit 202 to each data line 6a. The scanning line driving circuit 104 is electrically connected to each scanning line 3a, and sequentially supplies a scanning signal to each scanning line 3a.

  In each pixel 100a, the pixel electrode 9a is opposed to a common electrode formed on a counter substrate, which will be described later, via liquid crystal, and constitutes a liquid crystal capacitor 50a. Each pixel 100a is provided with a holding capacitor 60 in parallel with the liquid crystal capacitor 50a in order to prevent the image signal held in the liquid crystal capacitor 50a from leaking. In this embodiment, in order to configure the storage capacitor 60, the capacitor line 3b is formed in parallel with the scanning line 3a. The capacitor line 3b is connected to the common potential line COM and is held at a predetermined potential. Yes. The storage capacitor 60 may be formed between the preceding scanning line 3a.

  As shown in FIGS. 3A, 3B, and 3C, in the liquid crystal panel 100p of the electro-optical device 100, the element substrate 10 and the counter substrate 20 are sealed via a predetermined gap through a predetermined gap. The sealing material 107 is bonded along the edge of the counter substrate 20. The sealing material 107 is an adhesive made of a photo-curing resin, a thermosetting resin, or the like, and is mixed with a gap material such as glass fiber or glass beads for setting the distance between both substrates to a predetermined value.

  In the element substrate 10, a data line driving circuit 101 and a plurality of terminals 102 are formed along one side of the element substrate 10 in a region overlapping with the sealant 107 and its outer region, and along the side adjacent to the one side. A scanning line driving circuit 104 is formed. Further, at least one corner of the counter substrate 20 is formed with a vertical conductive material 109 for electrical conduction between the element substrate 10 and the counter substrate 20. The two scanning line driving circuits 104 are electrically connected by a wiring 105.

  As will be described in detail later, pixel electrodes 9 a made of an ITO (Indium Tin Oxide) film are formed in a matrix on the element substrate 10. On the other hand, a frame 108 made of a light-shielding material is formed in the inner area of the sealing material 107 on the counter substrate 20, and the inner side is an image display area 10 a. In the counter substrate 20, a light shielding film 23 called a black matrix or black stripe is formed in a region facing the vertical and horizontal boundary regions of the pixel electrode 9 a of the element substrate 10, and an ITO film is formed on the upper layer side thereof. A common electrode 21 is formed.

  In the pixel area 10b, a dummy pixel may be formed in an area overlapping with the frame 108. In this case, the area excluding the dummy pixel in the pixel area 10b is used as the image display area 10a. . In any case, the outside of the pixel area 10b (outside of the image display area 10a) is used as the peripheral circuit area 10d in which the scanning line driving circuit 104, the data line driving circuit 101, the plurality of terminals 102, and the wiring 105 are formed. The

(Detailed configuration of liquid crystal panel and element substrate)
4A and 4B are plan views of adjacent pixels in the element substrate 10 used in the electro-optical device 100 to which the present invention is applied, and electro-optics at positions corresponding to the AA ′ line. It is sectional drawing when the apparatus 100 is cut | disconnected.

  As shown in FIGS. 4A and 4B, in the liquid crystal panel 100p of the electro-optical device 100, the element substrate 10 and the counter substrate 20 are sealed via a predetermined gap through a predetermined gap (not shown). Z)). In the element substrate 10, a base protective film 12 made of a silicon oxide film or the like is formed on the surface of a translucent substrate 10s made of a quartz substrate, a glass substrate, or the like, and on the surface side, a position overlapping the pixel electrode 9a. In addition, an n-channel field effect transistor 30 is formed. The field effect transistor 30 includes a channel region 1g, a low concentration source region 1b, a high concentration source region 1d, a low concentration drain region 1c, and an island-shaped semiconductor layer 1a made of a polysilicon layer or a single crystal silicon layer. It has an LDD structure in which a high concentration drain region 1e is formed. A gate insulating layer 2 is formed on the surface side of the semiconductor layer 1a, and a gate electrode 3c (scanning line 3a) is formed on the surface of the gate insulating layer 2.

  Interlayer insulating layers 7 and 8 are formed on the upper layer side of the field effect transistor 30. A data line 6a and a drain electrode 6b are formed on the surface of the interlayer insulating layer 7, and the data line 6a is electrically connected to the high concentration source region 1d through a contact hole 7a formed in the interlayer insulating layer 7. Yes. The drain electrode 6b is electrically connected to the high concentration drain region 1e through a contact hole 7b formed in the interlayer insulating layer 7. A pixel electrode 9 a made of an ITO film is formed on the surface of the interlayer insulating layer 8. The pixel electrode 9 a is electrically connected to the drain electrode 6 b through a contact hole 8 a formed in the interlayer insulating layer 8. An alignment film 16 made of a polyimide film is formed on the surface side of the pixel electrode 9a. Further, the extension portion 1f (lower electrode) from the high-concentration drain region 1e has a capacitance in the same layer as the scanning line 3c through an insulating layer (dielectric film) formed simultaneously with the gate insulating layer 2. The storage capacitor 60 is configured by the line 3b facing as an upper electrode.

  The counter substrate 20 has a light shielding layer 23, a common electrode 21, an alignment film 26, and the like formed on a light transmitting substrate 20s made of a quartz substrate or a glass substrate.

  The element substrate 10 and the counter substrate 20 configured as described above are disposed so that the pixel electrode 9a and the common electrode 21 face each other, and the substrates are surrounded by a sealing material (not shown). A liquid crystal layer 50 as an electro-optical material is sealed in the space. The liquid crystal layer 50 takes a predetermined alignment state by the alignment films 16 and 22 in a state where an electric field from the pixel electrode 9a is not applied. The liquid crystal layer 50 is made of, for example, one or a mixture of several types of nematic liquid crystals.

(Configuration of drive circuit)
5A and 5B are a plan view of a complementary field effect transistor formed on an element substrate used in an electro-optical device to which the present invention is applied, and a position corresponding to the line BB ′. It is sectional drawing when an element substrate is cut | disconnected.

  3A, 3 </ b> B, and 3 </ b> C, in the electro-optical device 100 according to the present embodiment, the outer side of the pixel region 10 b (outside of the image display region 10 a) on the surface side of the element substrate 10 is a scanning line. It is used as a peripheral circuit region 10d in which a drive circuit 104, a data line drive circuit 101, a plurality of terminals 102, and a wiring 105 are formed. Such a data line driving circuit 101 and scanning line driving circuit 104 include, for example, a P-channel field effect transistor 80 and an N-channel field effect transistor as shown in FIGS. 90 and the like.

  5A and 5B, the field effect transistors 80 and 90 are formed by utilizing a part of the manufacturing process of the field switching transistor 30 for pixel switching. The semiconductor layers 1p and 1n constituting the transistors 80 and 90 are polysilicon layers or single crystal silicon layers, like the semiconductor layer 1a constituting the field effect transistor 30.

  The N-channel field effect transistor 90 includes an N-type source region (high-concentration source region 1s and low-concentration source region 1q) and a drain region (high-concentration drain region 1r and low-concentration drain region) on both sides of the channel region 1o. 1t), the P-channel field effect transistor 80 includes a P-type source region (high concentration source region 11 and low concentration source region 1j) and a drain region (high concentration drain) on both sides of the channel region 1i. A region 1m and a low concentration drain region 1k). A gate insulating layer 2 is formed on the surface side of the semiconductor layers 1p and 1n.

  In the field effect transistors 80 and 90, the high potential line 6e and the low potential line 6g are high concentration source regions of the semiconductor layers 1p and 1n through contact holes 7e and 7g penetrating the interlayer insulating layer 7 and the gate insulating layer 2. 1l and 1s are electrically connected. The output wiring 6f is electrically connected to the high-concentration drain regions 1m and 1r of the semiconductor layers 1p and 1n via contact holes 7f and 7k that penetrate the interlayer insulating layer 7 and the gate insulating layer 2, respectively. The input wiring 6h is connected to a common gate electrode 3e through a contact hole 7h that penetrates the interlayer insulating layer 7.

  In the peripheral circuit region 10d having such a configuration, since many metal wirings such as aluminum wirings are formed, the peripheral circuit region 10d has strong reflectivity.

(Return light measures)
6A, 6B, and 6C are plan views schematically showing a planar configuration of light scattering irregularities formed on the element substrate 10 of the electro-optical device 100 to which the present invention is applied, and a cross section thereof. It is sectional drawing of a figure and its modification.

  When the electro-optical device 100 and the liquid crystal panel 100p described with reference to FIGS. 2 to 5 are used as the liquid crystal light valves 115 to 117 and the liquid crystal panels 115c to 117c of the projection display device 110 described with reference to FIG. The light emitted from the light source unit 140 is incident from the side of the counter substrate 20 and is then optically modulated by the liquid crystal layer 50. As indicated by an arrow L1, in the element substrate 10, the first of the translucent substrate 10s. The light enters from the surface 10x side and exits from the second surface 10y. At this time, a part of the modulated light emitted from the element substrate 20 is reflected by, for example, the incident surface of the cross dichroic prism 119 and is incident as return light on the liquid crystal panel 100p as indicated by arrows L2 and L3. There is. Among such return lights, the return light indicated by the arrow L2 is incident on the pixel region 10b (image display region 10a) and causes the field effect transistor 30 to generate a light leakage current. Further, the return light indicated by the arrow L3 is light that is about to enter the peripheral circuit region 10d. If such light is regularly reflected by the peripheral circuit region 10d, the peripheral circuit is reflected in the projected image.

  Therefore, in this embodiment, as shown in FIGS. 3B and 4B and FIGS. 6A and 6B, in the pixel region 10b (image display region 10a), A light shielding layer 11 a made of a polysilicon film, a silicon nitride film, a titanium nitride film, or the like is formed in a region overlapping the field effect transistor 30 between the base protective film 12 and the base protective film 12.

  Further, as shown in FIG. 3C, FIG. 5B, and FIGS. 6A and 6B, a region that overlaps the peripheral circuit region 10d between the light-transmitting substrate 10s and the base protective film 12 Are formed with a plurality of light scattering irregularities 10t for scattering light incident from the second surface side of the translucent substrate 10s.

  In the present embodiment, each of the plurality of light scattering irregularities 10t includes a spherical concave portion 10v that is recessed in a spherical shape, and the spherical concave portion 10v has, for example, a diameter of several μm to several hundreds of μm and a depth of several 100 nm. Here, the inner surface of the spherical concave portion 10v is covered with a light shielding layer 11b, and the light shielding layer 11b is made of a polysilicon film, a silicon nitride film, a titanium nitride film, or the like, and is semi-transmissive capable of partially transmitting light. A light-shielding film. In this embodiment, the light shielding layer 11b is a film formed simultaneously with the light shielding layer 11a.

  The plurality of spherical recesses 10v are filled with a base protective film 12 made of a silicon oxide film or the like formed so as to cover the light shielding layer 11b. Here, the base protective film 12 is formed over the entire surface of the first surface 10x of the translucent substrate 10s, and the entire surface thereof is a flat surface. Therefore, in the translucent substrate 10s, the formation region of the plurality of light scattering irregularities 10t (spherical concave portions 10v) is a flat surface.

(Method for manufacturing element substrate 10)
With reference to FIG. 7, the manufacture of the electro-optical device 100 of this embodiment will be described with a focus on the process of forming the light scattering irregularities 10 t on the element substrate 10. FIG. 7 is a process cross-sectional view illustrating a process of forming the light scattering irregularities 10 t on the element substrate 10 in the manufacturing process of the electro-optical device 100 to which the present invention is applied.

  In order to manufacture the element substrate 10 used in the electro-optical device 100 of this embodiment, first, as shown in FIG. 7A, a light-transmitting substrate 10s made of a quartz substrate or a glass substrate is prepared, and then mask formation is performed. In the process, a resist mask 61 is formed on the first surface 10x using a photolithography technique. Here, the resist mask 61 includes an opening 610 at a location corresponding to the spherical recess 10v shown in FIG.

  Next, in the recess forming step shown in FIG. 7B, wet etching is performed on the first surface 10x of the translucent substrate 10s through the opening 610 of the resist mask 61 to form the spherical recess 10v. That is, according to the wet etching, since the etching proceeds isotropically from the opening 610, the spherical recess 10v can be formed.

  Next, after removing the resist mask 61, as shown in FIG. 7C, a polysilicon film, a silicon nitride film for forming the light shielding layers 11a and 11b on the first surface 10x of the translucent substrate 10s, The light shielding film 11 is formed of a titanium nitride film or the like.

  Next, as shown in FIG. 7D, a resist mask 62 is formed on the surface of the light shielding film 11 by using a photolithography technique. Here, the resist mask 62 covers the region where the light shielding layers 11a and 11b are to be formed, and has an opening 620 in the other region.

  Next, as shown in FIG. 7E, wet etching or dry etching is performed on the light-shielding film 11 through the opening 620 of the resist mask 62, and then the resist mask 62 is removed. ), The light shielding layers 11a and 11b are formed.

  Next, a base protective film 12 made of a silicon oxide film or the like is formed on the entire first surface 10x of the translucent substrate 10s so as to cover the light shielding layers 11a and 11b, and then the surface of the base protective film 12 is planarized. To do. In performing the planarization, for example, chemical mechanical polishing is performed. In this chemical mechanical polishing, a smooth polished surface can be obtained at a high speed by the action of chemical components contained in the polishing liquid and the relative movement between the abrasive and the light transmitting substrate 20s. More specifically, in the polishing apparatus, while relatively rotating the surface plate on which a polishing cloth (pad) made of nonwoven fabric, foamed polyurethane, porous fluororesin or the like is attached, and the holder holding the light-transmitting substrate 20fs, Polish. At that time, for example, an abrasive containing cerium oxide particles having an average particle diameter of 0.01 to 20 μm, an acrylate derivative as a dispersant, and water is supplied between the polishing cloth and the translucent substrate 20s. In this way, the inside is filled with the silicon oxide film (base protective film 12 / filling material) formed so that the spherical concave portion 10v covers the light shielding layer 11b, and the base protective film 12 allows the translucent substrate 10s. The region in which the plurality of spherical concave portions 10v are formed can be flattened.

  Thereafter, a single crystal silicon layer is formed by a bonding technique between the single crystal silicon substrate and the light-transmitting substrate 10s, or a polycrystal by a crystallization process such as laser annealing or rapid heating after the amorphous silicon film is formed. After the silicon layer formation step, field effect transistors 30, 80, 90, etc. are formed using the silicon layer. Since well-known methods can be applied to the subsequent steps, descriptions thereof are omitted.

(Main effects of this form)
As described above, in the electro-optical device 100 according to the present embodiment, the light-shielding layer 11a is disposed in a region overlapping the field effect transistor 30 between the base protective film 12 and the light-transmitting substrate 10s used as the element substrate 10. Therefore, the modulated light is reflected by the surface on the emission side of the element substrate 10 and the incident surface of the cross dichroic prism 119 shown in FIG. 1, and is returned as the return light indicated by the arrow L2 on the element substrate 10 side. Even when the light enters the field effect transistor 30, since the return light does not reach the field effect transistor 30, no light leakage current is generated in the field effect transistor 30.

  Further, even when the modulated light is incident on the peripheral circuit region 10d of the element substrate 10 as the return light indicated by the arrow L3, the light transmitting substrate 10s used for the element substrate 10 has the same effect on the peripheral circuit region 10d. A plurality of light scattering irregularities 10t (spherical concave portions 10v) are formed in the overlapping region, and the inner surfaces of the spherical concave portions 10v are covered with the light shielding layer 11b in the light scattering irregularities 10t. For this reason, the return light is scattered when reflected by the outer surface of the spherical recess 10v, as indicated by the arrow L5. Accordingly, since the return light is not regularly reflected by the peripheral circuit region 10d, it is possible to prevent the peripheral circuit region 10d from appearing in the outer edge portion of the projection image.

  In addition, when a solid light-shielding film is formed in a region overlapping the peripheral circuit region 10d in the light-transmitting substrate 10s used for the element substrate 10, the presence of the light-shielding film is displayed on a projection surface such as a screen. Although the image is reflected along the outer edge, in this embodiment, the return light is scattered by the light scattering unevenness 10t, so that such a problem does not occur.

  In addition, since the reflection direction is dispersed due to the spherical concave portion 10v, strong light is not reflected toward a specific direction. Therefore, the light reflected by the light scattering irregularities 10t does not deteriorate the quality of the projected image.

  Moreover, since the light shielding layer 11b is a semi-transmissive light shielding film capable of partially transmitting light, only a part of the light indicated by the arrow L3 is reflected by the inner surface of the spherical recess 10v, and the other part is indicated by the arrow. As indicated by L4, the light passes through the light shielding layer 11b. For this reason, the amount of return light emitted again from the element substrate 10 side is small. Here, as indicated by the arrow L4, a part of the return light passes through the light shielding layer 11b and reaches the peripheral circuit region 10d, but the return light is emitted from the second surface 10y of the translucent substrate 10s. At this time, since the light is reflected and scattered by the inner surface of the spherical recess 10v, the peripheral circuit region 10d does not appear in the outer edge portion of the projection image.

  Further, the inside of the plurality of spherical concave portions 10v is filled with the base protective film 12, and the formation region of the light scattering irregularities 10t (spherical concave portions 10v) is a flat surface. Therefore, even when the peripheral circuit is formed on the light-transmitting substrate 10s on the region where the light scattering unevenness 10t is formed, the peripheral circuit can be formed in a region without the step due to the light scattering unevenness 10t. Therefore, it is possible to reliably prevent the reliability of the peripheral circuit from being lowered.

[Modification of Embodiment 1]
In the first embodiment, since the spherical recess 10v is formed on the first surface 10x of the translucent substrate 10s, the light scattering irregularity 10t (spherical recess 10v) is spherical on the incident side of the translucent return light. As shown in FIG. 6C, a spherical concave portion 10v is formed on the second surface 10y of the translucent substrate 10s, and a light shielding layer is formed on the inner surface of the spherical concave portion 10v. A configuration in which 11a is formed and the inside of the spherical concave portion 10v is filled with the silicon oxide film 12a (filling material) may be employed. In this case, a base protective film may be separately formed on the first surface 10x of the translucent substrate 10s as necessary.

[Embodiment 2]
8A, 8B, and 8C are planes schematically showing a planar configuration of light scattering irregularities formed on the element substrate 10 of the electro-optical device 100 according to Embodiment 2 of the present invention. It is sectional drawing of the figure, its sectional drawing, and its modification. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

  In the first embodiment, the light scattering unevenness 10t is formed using the spherical concave portion 10v in the region overlapping the peripheral circuit region 10d in the translucent substrate 10s used for the element substrate 10, but in this embodiment, As shown in FIGS. 8A and 8B, in the translucent substrate 10s, a plurality of groove-shaped recesses 10w having an arc-shaped cross section are formed in a region overlapping the peripheral circuit region 10d. 10w extends in parallel along the side of the translucent substrate 10s.

  The groove-shaped recess 10w has an inner surface covered with a light-shielding layer 11b, and the light-shielding layer 11b is made of a polysilicon film, a silicon nitride film, a titanium nitride film, or the like, and is semi-transmissive that can partially transmit light. It is a light shielding film. In this embodiment, the light shielding layer 11b is a film formed simultaneously with the light shielding layer 11a.

  The groove-shaped recess 10w is filled with a base protective film 12 made of a silicon oxide film formed so as to cover the light shielding layer 11b. Here, the base protective film 12 is formed over the entire surface of the first surface 10x of the translucent substrate 10s, and the entire surface thereof is a flat surface. Therefore, in the translucent substrate 10s, the formation region of the plurality of light scattering irregularities 10t (groove-shaped concave portions 10w) is a flat surface.

  Since the manufacturing method of the light scattering unevenness 10t having such a configuration can be manufactured by the method described with reference to FIG. 7, the description thereof will be omitted. In this embodiment, the return light indicated by the arrow L3 is also transmitted to the element substrate 10. Even when the light is incident on the peripheral circuit region 10d, the same effects as those of the first embodiment can be obtained, such as preventing the peripheral circuit region 10d from being reflected in the outer edge portion of the projection image.

  In this embodiment, since the groove-shaped recess 10w is formed on the first surface 10x of the light-transmitting substrate 10s, the light scattering unevenness 10t (the groove-shaped recess 10w) has a protrusion on the incident side of the light-transmitting return light. As shown in FIG. 8C, the groove-shaped recess 10w is formed on the second surface 10y of the translucent substrate 10s, and the light-shielding layer 11a is formed on the inner surface of the groove-shaped recess 10w. A structure in which the inside of the groove-shaped recess 10w is buried with the silicon oxide film 12a (filling material) may be employed.

[Embodiment 3]
FIG. 9 is an explanatory diagram schematically showing a cross-sectional configuration of light scattering irregularities formed on the element substrate 10 of the electro-optical device 100 according to Embodiment 3 of the present invention. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

  In the first and second embodiments, the light shielding layer 11b is formed so as to cover the inner surfaces of the spherical concave portion 10v and the groove-shaped concave portion 10w constituting the light scattering irregularity 10t, but as shown in FIG. The translucent material 12b having a refractive index different from that of the translucent substrate 10b may be formed so as to cover the inner surfaces of the spherical recess 10v and the groove-shaped recess 10w. According to such a configuration, the return light can be scattered by the refraction action of the light scattering unevenness 10t.

  Here, the translucent material 12b may have a refractive index different from that of the translucent substrate 10s. If the translucent substrate 10s is a quartz substrate or a glass substrate, the refractive index is about 1.45. Therefore, titanium oxide (refractive index = 2.5), silicon nitride (refractive index = 2.0), and polysilicon (refractive index = 3.5) can be used as the translucent material.

  Even when such a configuration is adopted, if the inside of the spherical concave portion 10v and the groove-shaped concave portion 10w is filled with the translucent material 12b, the formation region of the light scattering unevenness 10t can be made flat. Therefore, even when the peripheral circuit is formed on the light-transmitting substrate 10s on the region where the light scattering unevenness 10t is formed, the peripheral circuit can be formed in a region without the step due to the light scattering unevenness 10t. Therefore, it is possible to reliably prevent the reliability of the peripheral circuit from being lowered.

  Also in this embodiment, depending on the transmittance of the light transmissive material 12b, the light transmissive material 12b may be formed as it is as a base protective film. In that case, the light transmissive material 12b is formed on the entire surface of the light transmissive substrate 10s. Just leave it in. Further, when the transmissivity of the translucent material 12b is low, the translucent material 12b may be formed only inside the spherical recess 10v and the groove recess 10w as shown in FIG. 9 (d). Also in this embodiment, the light scattering unevenness 10t may be formed on either the first surface or the second surface of the translucent substrate 10s, and in either case, the light scattering unevenness 10t has a positive power or a negative power. Therefore, the return light can be scattered.

  In order to manufacture the element substrate 10W having such a configuration, the resist mask 61 is formed on the translucent substrate 10s made of a quartz substrate or a glass substrate in the mask formation step shown in FIG. 9B, in the recess forming step in FIG. 9B, wet etching is performed on the translucent substrate 10s through the opening 610 of the resist mask 61 to form the spherical recess 10v or the groove-like recess 10w. . Next, after removing the resist mask 61, as shown in FIG. 9C, a translucent material layer 12c is formed on the translucent substrate 10s, and then the translucent material layer 12c is formed on the surface. By polishing from the side, as shown in FIG. 9D, the translucent material 12b (the translucent material layer 12c) may be left only in the spherical concave portion 10v and the groove-shaped concave portion 10w.

[Other embodiments]
FIG. 1 illustrates a projection display device using three light valves. However, when the electro-optical device 100 includes a color filter, the present invention is applied to the projection display device shown in FIG. One electro-optical device 100 may be used as a light valve, and a color image may be projected and displayed on the screen 211. 10 includes a light source unit 240 including a white light source 212, an integrator 221, and a polarization conversion element 222, the electro-optical device 100, and a projection optical system 218. In the electro-optical device 100, the first polarizing plate 216a and the second polarizing plate 216b are arranged on both sides of the liquid crystal panel 100x with a built-in color filter.

  Furthermore, although the liquid crystal device has been described as an example of the electro-optical device in the above embodiment, the present invention is applied as a countermeasure against the return light even when the projection display device is configured by the modulated light emitted from the self-light emitting element. Also good.

It is a schematic block diagram of the projection type display apparatus to which this invention is applied. It is a block diagram which shows the electrical constitution of the liquid crystal panel used for the liquid crystal light valve in the projection type display apparatus shown in FIG. (A), (b), and (c) are plan views of the liquid crystal panel of the electro-optical device to which the present invention is applied as viewed from the side of the counter substrate together with the respective components, its HH ′ sectional view, and I It is -I 'sectional drawing. FIGS. 4A and 4B are plan views of adjacent pixels on the element substrate used in the electro-optical device to which the present invention is applied, and the electro-optical device cut at a position corresponding to the line AA ′. FIG. (A), (b) is a plan view of a complementary field effect transistor formed on an element substrate used in an electro-optical device to which the present invention is applied, and an element substrate at a position corresponding to the BB ′ line. It is sectional drawing when cutting. (A), (b), (c) is the top view which shows typically the planar structure of the unevenness | corrugation for light scattering formed in the element substrate of the electro-optical apparatus based on Embodiment 1 of this invention, The cross section It is sectional drawing of a figure and its modification. It is process sectional drawing which shows the process of forming the unevenness | corrugation for light scattering in an element substrate among the manufacturing processes of the electro-optical apparatus to which this invention is applied. (A), (b), (c) is the top view which shows typically the planar structure of the unevenness | corrugation for light scattering formed in the element substrate of the electro-optical apparatus based on Embodiment 2 of this invention, The cross section It is sectional drawing of a figure and its modification. FIG. 10 is an explanatory diagram schematically showing a cross-sectional configuration of light scattering irregularities formed on an element substrate of an electro-optical device according to Embodiment 3 of the present invention. It is a schematic block diagram of another projection type display apparatus to which this invention is applied. It is explanatory drawing which shows the problem of the conventional electro-optical apparatus and a projection type display apparatus.

Explanation of symbols

10 .. Element substrate, 10a .. Image display area, 10b .. Pixel area, 10d .. Peripheral circuit area, 10t .. Light scattering unevenness, 10v .. Spherical recess, 10w .. Groove recess, 10x.・ First surface of translucent substrate, 10y ・ ・ Second surface of translucent substrate, 20 ・ ・ Counter substrate, 100 ・ ・ Electro-optical device (liquid crystal device / liquid crystal light valve), 100p ・ ・ Liquid crystal panel, 110, 210 .. projection type display device

Claims (10)

A pixel region in which a plurality of pixels each including a pixel electrode and a pixel transistor are formed on the first surface side of the translucent substrate; and a peripheral circuit in which a plurality of wiring and driving circuit transistors are formed outside the pixel region; in the electro-optical device for emitting light modulated from the second surface side opposite to the comprises a device substrate, the first surface of the light transmissive substrate having,
Wherein the area overlapping with the peripheral circuit of the light-transmissive substrate, said has a plurality of light scattering irregularities for scattering light incident from the second surface side of the translucent substrate is formed,
An electro-optical device , wherein an inner surface of the concave portion constituting the plurality of light scattering irregularities is covered with a light shielding layer . The plurality of recesses are filled with a filling material formed so as to cover the light shielding layer,
2. The electro-optical device according to claim 1 , wherein a region where the plurality of concave portions of the translucent substrate is formed is flattened by the filling material. The electro-optical device according to claim 2 , wherein the light-shielding layer is a semi-transmissive light-shielding film capable of partially transmitting light. A pixel region in which a plurality of pixels each including a pixel electrode and a pixel transistor are formed on the first surface side of the translucent substrate; and a peripheral circuit in which a plurality of wiring and driving circuit transistors are formed outside the pixel region; In an electro-optical device that emits modulated light from a second surface side opposite to the first surface of the translucent substrate,
A plurality of light scattering irregularities that scatter light incident from the second surface side of the translucent substrate is formed in a region overlapping the peripheral circuit of the translucent substrate,
An electro-optical device, wherein inner surfaces of a plurality of recesses constituting the plurality of light scattering irregularities are covered with a light-transmitting material having a refractive index different from that of the light-transmitting substrate. The recess is filled with the translucent material inside,
By the translucent material, an electro-optical device according to claim 4, characterized in that the formation region of the plurality of recesses of the translucent substrate is planarized. A pixel region in which a plurality of pixels each including a pixel electrode and a pixel transistor are formed on the first surface side of the translucent substrate; and a peripheral circuit in which a plurality of wiring and driving circuit transistors are formed outside the pixel region; In an electro-optical device that emits modulated light from a second surface side opposite to the first surface of the translucent substrate,
A plurality of light scattering irregularities that scatter light incident from the second surface side of the translucent substrate is formed in a region overlapping the peripheral circuit of the translucent substrate,
It said plurality of light scattering irregularities to an electro-optical apparatus characterized by being composed of a plurality of recesses recessed in spherical the transmissive substrate. A pixel region in which a plurality of pixels each including a pixel electrode and a pixel transistor are formed on the first surface side of the translucent substrate; and a peripheral circuit in which a plurality of wiring and driving circuit transistors are formed outside the pixel region; In an electro-optical device that emits modulated light from a second surface side opposite to the first surface of the translucent substrate,
A plurality of light scattering irregularities that scatter light incident from the second surface side of the translucent substrate is formed in a region overlapping the peripheral circuit of the translucent substrate,
Said plurality of light scattering irregularities, electro-optical device characterized in that it is constituted by an arc-shaped cross section of the plurality of recessed grooves of the translucent substrate. A counter substrate disposed opposite to the element substrate;
The electro-optical device according to any one of claims 1 to 7, characterized in that the liquid crystal layer is held between the counter substrate and the element substrate. A pixel region in which a plurality of pixels each including a pixel electrode and a pixel transistor are formed on the first surface side of the translucent substrate; and a peripheral circuit in which a plurality of wiring and driving circuit transistors are formed outside the pixel region; In the method of manufacturing an electro-optical device that emits light modulated from the second surface side opposite to the first surface in the translucent substrate,
In a region which overlaps with the peripheral circuit of the light-transmitting substrate, in forming a plurality of light scattering irregularities for scattering light incident from the second surface side of the transparent substrate,
A mask forming step of forming a mask having an aperture in a region to be the concave portions of the plurality of light scattering irregularities with respect to the light-transmitting substrate;
And a recess forming step of performing wet etching on the light-transmitting substrate from the opening. A projection display device using the electro-optical device according to any one of claims 1 to 8 ,
A projection display device comprising a projection optical system that projects light modulated by the electro-optical device.

Images