JP4900164B2 - Electro-optical device, method of manufacturing electro-optical device, and projection display device - Google Patents

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, the influence of the return light is not only the light leakage current of the pixel transistor. That is, in the element substrate of the electro-optical device, the metal wiring and the metal electrodes are arranged with 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. 9, 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 driver circuit transistor includes an element substrate having the peripheral circuits formed in plurality, in the electro-optical device for emitting light modulated from the second surface side opposite to the first surface in said light transmissive substrate, wherein in a region which overlaps with the peripheral circuit of the light-transmitting substrate, wherein the roughened region to scatter light incident from the second surface side of the translucent substrate are formed, the roughened region, wherein It is characterized by comprising a large number of dot-like deposits deposited on the light-transmitting substrate .

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 roughened region for roughening a region overlapping the peripheral circuit of the translucent substrate to form a roughened region for scattering light incident from the second surface side of the translucent substrate. have a forming process, in the roughening region forming step, and performing a chemical vapor deposition process for forming a plurality of dot-like deposits by chemical vapor deposition on the light-transmitting substrate .

  In the present invention, since the roughened region is formed in the region that overlaps the peripheral circuit region in the light-transmitting substrate used as the element substrate, the modulated light is emitted from the surface on the output side of the element substrate or the electro-optics. Even when the light is reflected by an optical system or the like disposed on the emission side with respect to the apparatus and is incident as return light from the element substrate side, the return light is scattered by the roughened region. 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 in the roughened region, such a problem does not occur.

  In the present invention, the roughened region is preferably composed of a large number of dot-like deposits deposited on the translucent substrate. In order to manufacture an electro-optical device having such a configuration, a chemical vapor deposition step of forming a large number of dot-like deposits by a chemical vapor deposition method on the light-transmitting substrate in the roughened region forming step is performed. It is preferable to do so. If comprised in this way, the rough surface with arbitrary light-scattering properties can be formed easily. In addition, since a part of the incident return light is reflected while being scattered and the remaining part is transmitted while being scattered, regular reflection in the peripheral circuit region can be reliably prevented.

  In the present invention, the dot deposit is preferably composed of a particulate silicon deposit or a particulate metal deposit.

  In the present invention, the roughened region is formed at the bottom of a recess formed in the light-transmitting substrate, the recess is filled with a filling material, and the recess in the light-transmitting substrate is filled with the filling material. The formation region of is preferably planarized. If comprised in this way, even when a roughening area | region is comprised with many dot-like deposits, a dot-like deposit can be protected and peeling of a dot-like deposit can be prevented. Even when a peripheral circuit is formed on a region where a recess is formed on the element substrate, the peripheral circuit can be formed in a region without a step due to the recess, and the reliability of the peripheral circuit is reduced by the step. It can be surely prevented.

  In order to manufacture the electro-optical device having such a configuration, for example, in the roughened region forming step, a concave portion forming step of forming a concave portion in the region to be the roughened region in the translucent substrate, and the transparent surface The chemical vapor deposition step for the region including the concave portion in the optical substrate, the concave filling step for forming a filling material layer on the translucent substrate so as to fill at least the concave portion, and formed outside the concave portion. And a polishing step of polishing the translucent substrate until the dot-like deposits are removed. If comprised in this way, while a dot-like deposit can be selectively left in the bottom part of a recessed part, the formation area of the said recessed part can be planarized in a translucent board | substrate.

  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.

  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.

(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 transmissive 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 center region. ing. 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 faces a common electrode formed on a counter substrate, which will be described later, via a liquid crystal layer, 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, for the extended portion 1f (lower electrode) from the high concentration drain region 1e, the capacitance of the same layer as that of the scanning line 3a is provided via 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 26 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 enters the liquid crystal panel 100p as indicated by an arrow L3. At this time, if the light directed to the peripheral circuit region 10d 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, 3C, 5B, 6A, and 6B, the peripheral circuit region 10d in the translucent substrate 10s is formed. In the overlapping region, a roughened region 10t that scatters light incident from the second surface 10y side of the translucent substrate 10s is formed. In forming the roughened region 10t, in this embodiment, the second surface 10y of the translucent substrate 10s is formed with a recess 10v in a region overlapping the peripheral circuit region 10d, and the bottom surface of the recess 10v. Is roughened.

  More specifically, a large number of dot-like deposits 11 made of a particulate silicon deposit or a particulate metal deposit are formed on the bottom surface and the inner side surface of the recess 10v. Thus, the bottom surface of the recess 10v is roughened. Here, the dot-like deposit 11 has a particle size of, for example, sub-nano order to micron order.

  The concave portion 10v is filled with a filling material layer 13 made of a silicon oxide film or the like, and the second surface 10y of the translucent substrate 10s is a flat surface as a whole including the formation region of the concave portion 10v.

(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 focusing on the step of forming the roughened region 10t on the element substrate 10 (roughened region forming step). FIG. 7 is a process cross-sectional view illustrating a process of forming the roughened region 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 second surface 10y by using a photolithography technique. Here, the resist mask 61 includes an opening 610 at a location corresponding to the recess 10v shown in FIG.

  Next, in the recess forming step shown in FIG. 7B, dry etching is performed on the second surface 10y of the translucent substrate 10s through the opening 610 of the resist mask 61 to form the recess 10v.

  Next, after removing the resist mask 61, in the chemical vapor deposition process shown in FIG. 7C, the entire surface of the second surface 10y of the translucent substrate 10s is formed by using a chemical vapor deposition method. On the other hand, a large number of dot deposits 11 made of silicon or metal are formed. That is, when a film is formed by the chemical vapor deposition method, the film formation is performed under the condition that the deposit is in a particle shape among the conditions in which the deposit is in a particle shape and the condition in which the deposit is a flat film. The film formation is stopped before the deposit is formed on the entire surface. For example, when the dot-like deposit 11 is formed by a silicon deposit, a silane gas is used as a source gas, a chemical vapor deposition is performed under conditions where the temperature is relatively high (for example, 400 to 500 ° C.) and the pressure is 1 to 30 Torr. Do the membrane. For the dot-like deposit 11, a metal deposit such as tungsten may be used.

  Next, in the recess filling step shown in FIG. 7D, a filling material layer 13 made of a silicon oxide film or the like is formed to a thickness that fills at least the recess 10v. As a result, the filling material layer 13 is formed on substantially the entire second surface 10y of the translucent substrate 10s.

  Next, in the polishing step shown in FIG. 7E, the second surface 10y of the translucent substrate 10s is polished until the dot-like deposit 11 formed outside the recess 10v is removed. As a result, the dot-like deposit 11 remains only in the recess 10v, the filling material layer 13 also remains only in the recess 10v, and the entire second surface 10y of the translucent substrate 10s including the formation region of the recess 10v is flat. It becomes a surface. In performing such polishing, 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.

  Thereafter, as shown in FIGS. 4B and 5B, a base protective film 12 made of a silicon oxide film or the like is formed on the first surface 10x of the translucent substrate 10s, and then a single crystal silicon substrate. A step of forming a single crystal silicon layer by a bonding technique between the substrate and the translucent substrate 10s or a step of forming a polysilicon layer by crystallization treatment such as laser annealing or rapid heating after forming an amorphous silicon film was performed. Thereafter, field effect transistors 30, 80, 90, and the like 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 modulated light is reflected by the exit side surface of the element substrate 10 or the entrance surface of the cross dichroic prism 119 shown in FIG. Even when the return light shown is incident from the element substrate 10 side, a roughened region 10t (dot-like deposit 11) is formed in a region overlapping the peripheral circuit region 10d in the translucent substrate 10s used for the element substrate 10. Has been. For this reason, as shown by the arrow L5, the return light is scattered when reflected by the roughened region 10t. 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, since the return light is scattered in the roughened region 10t, such a problem does not occur.

  In addition, since the roughened region 10t has a configuration in which a large number of dot-like deposits 11 are formed, a part of the light indicated by the arrow L3 passes through the translucent substrate 10s. For this reason, the amount of return light reflected by the element substrate 10 is small. Here, as indicated by the arrow L4, a part of the return light is transmitted through the translucent substrate 10s, but the light is scattered, and even if the return light is reflected by the peripheral circuit region 10d. The reflected light is scattered again in the roughened region 10t. Therefore, the peripheral circuit region 10d does not appear in the outer edge portion of the projection image.

  Furthermore, since the concave portion 10v is filled with the filling material layer 13, even when the roughened region 10t is composed of a large number of dot-like deposits 11, the dot-like deposits 11 can be protected and the dot-like deposits can be protected. 11 can be prevented.

[Another embodiment]
In the above embodiment, the recess 10v is formed on the second surface 10y of the translucent substrate 10s, and the dot-like deposit 11 is formed on the bottom thereof. However, as shown in FIG. While forming the recessed part 10v in the 1st surface 10x of 10s, you may form the dot-like deposit 11 in the bottom part of the recessed part 10v. Also in this case, the interior of the recess 10v is filled with the filling material layer 13. For this reason, even when the roughened region 10t is constituted by a large number of dot-like deposits 11, the dot-like deposits 11 can be protected, and peeling of the dot-like deposits 11 can be prevented. Even when the peripheral circuit is formed on the region where the recess 10v is formed, the peripheral circuit can be formed in a region where there is no useless step, and the reliability of the peripheral circuit is reliably prevented from being lowered by the step. be able to.

  Further, a light shielding layer for preventing return light from entering the field effect transistor 30 may be formed in a region overlapping the field effect transistor 30 between the base protective film 12 and the translucent substrate 10 s. Good. Further, in the translucent substrate 10 s, a roughened region 10 t (concave portion 10 v and dot-like deposit 11) is formed in a region overlapping with the field effect transistor 30, and the return light is directly incident on the field effect transistor 30. May be prevented.

  Note that an antireflection layer may be formed on the element substrate 10 between the base protective film 12 and the translucent substrate 10s or on the second surface 10y of the translucent substrate 10s. For example, it can be formed by laminating a silicon oxide film and a titanium oxide film.

  Further, the roughened region 10t may be configured by forming fine irregularities directly on the substrate surface of the translucent substrate 10s.

[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. That is, the projection display apparatus 210 shown in FIG. 8 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 disposed on both sides of the liquid crystal panel 100p 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 a plan view schematically showing a planar configuration of a roughened region formed on an element substrate of an electro-optical device to which the present invention is applied, its sectional view, and its It is sectional drawing of a modification. It is process sectional drawing which shows the process of forming a roughening area | region in an element substrate among the manufacturing processes of the electro-optical apparatus to which this invention is applied. 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, Roughened area, 10v, Recess, 10x, First surface of translucent substrate 10 y... Second surface of translucent substrate, 11... Dot-like deposit, 20.. Counter substrate, 100 .. electro-optical device (liquid crystal device / liquid crystal light valve), 100 p. 210 .. Projection type display device

Claims (7)

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 light modulated from a second surface side opposite to the first surface in the translucent substrate,
A roughened region for scattering light incident from the second surface side of the translucent substrate is formed in a region overlapping the peripheral circuit of the translucent substrate,
The electro-optical device, wherein the roughened region is constituted by a large number of dot-like deposits deposited on the translucent substrate.   The electro-optical device according to claim 1, wherein the dot-like deposit is made of a particulate silicon deposit or a particulate metal deposit. 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 light modulated from a second surface side opposite to the first surface in the translucent substrate,
A roughened region for scattering light incident from the second surface side of the translucent substrate is formed in a region overlapping the peripheral circuit of the translucent substrate,
The roughened region is formed at the bottom of a recess formed in the translucent substrate,
The recess is filled with a filler material layer,
The electro-optical device is characterized in that a formation region of the recess is flattened in the translucent substrate by the filling material layer. A counter substrate disposed opposite to the element substrate;
4. The electro-optical device according to claim 1, wherein a 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,
A roughening region forming step of roughening a region overlapping the peripheral circuit of the translucent substrate to form a roughened region that scatters light incident from the second surface side of the translucent substrate; Yes, and
In the roughening region forming step, a chemical vapor deposition step of forming a large number of dot-like deposits on the translucent substrate by a chemical vapor deposition method is performed. . Wherein in the roughening region forming step, a recess forming step of forming a recess in the region said to be a roughened region of the transmissive substrate, the chemical vapor to the area containing the recess of the translucent substrate A film forming step, a recess filling step of forming a filling material layer on the translucent substrate so as to fill at least the recess, and the light transmission until the dot-like deposit formed outside the recess is removed. A method for manufacturing an electro-optical device according to claim 5, wherein a polishing step for polishing the conductive substrate is performed. A projection display device using the electro-optical device according to any one of claims 1 to 4,
A projection display device comprising a projection optical system that projects light modulated by the electro-optical device.

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