JP2020126250A - Electrooptical device and electronic apparatus - Google Patents

Abstract

To provide an electrooptical device which can increase the light shieling property for a switching element while reducing generation of failures, and to provide a high-quality electronic apparatus having the electrooptical device.SOLUTION: The present invention includes: a translucent base material; a translucent pixel electrode; a switching element electrically connected to the pixel electrode; and a light shieling body in contact with the base material and overlapping with the switching element in a planer view from the thickness direction of the base material, the light shieling body having a first part and a second part thicker than the first part. It is preferable that the base material has an opening on the pixel electrode side and has a recess in which the light shieling body is arranged.SELECTED DRAWING: Figure 6

Description

The present invention relates to an electro-optical device and electronic equipment.

Electro-optical devices such as liquid crystal devices are used in electronic devices such as projectors. Patent Document 1 discloses an electro-optical device including an element substrate, a counter substrate, and liquid crystal disposed between them.

The element substrate described in Patent Document 1 includes a quartz substrate, a plurality of pixel electrodes that are spaced apart from the quartz substrate and arranged in a matrix, and a TFT (Thin Film Transistor) provided corresponding to each pixel electrode. .. Further, the element substrate described in Patent Document 1 includes a light-shielding film made of metal or the like in order to suppress light from entering the TFT.

JP, 2005-250234, A

Regarding the light-shielding film described in Patent Document 1, it can be considered to increase the thickness of the light-shielding film in order to improve the light-shielding property. However, in the element substrate described in Patent Document 1, if the thickness of the light shielding film is simply made uniform, the stress generated in the base material becomes excessively large. As a result, defects such as warpage of the base material and cracks of the light shielding film occur. Therefore, the conventional element substrate has a problem that it is difficult to enhance the light shielding property for the TFT while reducing the occurrence of such a defect.

One aspect of an electro-optical device of the present invention is a translucent base material, a translucent pixel electrode, a switching element electrically connected to the pixel electrode, and a base material that is in contact with the base material. A light-shielding body that overlaps with the switching element when viewed in a plan view from the thickness direction of the material, the light-shielding body includes a first portion and a second portion having a thickness larger than the thickness of the first portion. Have.

FIG. 3 is a plan view of a liquid crystal device which is an example of the electro-optical device according to the first embodiment. FIG. 3 is a cross-sectional view of the liquid crystal device according to the first embodiment. It is an equivalent circuit diagram which shows the electric constitution of the element substrate in 1st Embodiment. FIG. 3 is a partial plan view of the element substrate in the first embodiment. FIG. 3 is a partial cross-sectional view of the element substrate in the first embodiment. It is sectional drawing which shows the light-shielding body which the element substrate in 1st Embodiment has. FIG. 3 is a plan view showing a light shield body included in the element substrate in the first embodiment. FIG. 3 is a plan view showing a TFT included in the element substrate according to the first embodiment. It is sectional drawing which shows the light-shielding body for circuits which the element substrate in 1st Embodiment has. 6 is a flowchart showing a method of manufacturing the element substrate according to the first embodiment. It is sectional drawing for demonstrating the base material formation process in 1st Embodiment. It is sectional drawing for demonstrating the base material formation process in 1st Embodiment. FIG. 6 is a cross-sectional view for explaining a light-shielding body forming step in the first embodiment. FIG. 6 is a cross-sectional view for explaining a light-shielding body forming step in the first embodiment. It is a top view which shows the light-shielding body which the element substrate in 2nd Embodiment has. It is sectional drawing which shows the light-shielding body which the element substrate in 3rd Embodiment has. It is sectional drawing which shows the light-shielding body which the element substrate in 4th Embodiment has. It is sectional drawing which shows the light-shielding body which the element substrate in 5th Embodiment has. It is a top view which shows the light-shielding body which the element substrate in 5th Embodiment has. It is a perspective view showing a personal computer which is an example of electronic equipment. It is a perspective view which shows the smart phone which is an example of an electronic device. It is a schematic diagram which shows the projector which is an example of an electronic device.

Preferred embodiments according to the present invention will be described below with reference to the accompanying drawings. In the drawings, the size and scale of each part are different from the actual ones, and some parts are schematically shown for easy understanding. Further, the scope of the present invention is not limited to these forms unless there is a description in the following description that the present invention is particularly limited. In addition, in this specification, "parallel" means not only when two surfaces or lines are completely parallel to each other, but also when one is inclined within ±5° with respect to the other.

1. Liquid Crystal Device 1-1. First Embodiment As an example of the electro-optical device of the present invention, an active matrix type liquid crystal device including a TFT (Thin Film Transistor) as a switching element will be described as an example.

1-1a. Basic Configuration FIG. 1 is a plan view of a liquid crystal device which is an example of the electro-optical device according to the first embodiment. 2 is a cross-sectional view of the liquid crystal device according to the first embodiment and is a cross-sectional view taken along the line AA in FIG. In the following description, for convenience of description, the x-axis, the y-axis, and the z-axis, which are shown in FIGS. 1 and 2 and are orthogonal to each other, are used as appropriate.

The electro-optical device 1 shown in FIGS. 1 and 2 is a transmissive liquid crystal device. The electro-optical device 1 is arranged between the element substrate 2 having a light-transmitting property, the counter substrate 3 having a light-transmitting property arranged so as to face the element substrate 2, and the element substrate 2 and the counter substrate 3. It has a frame-shaped seal member 4, and a liquid crystal layer 5 surrounded by the element substrate 2, the counter substrate 3, and the seal member 4.

The light that passes through the electro-optical device 1 is visible light, and in this specification, the light-transmitting property means the transparency to visible light, and preferably, the visible light transmittance is 50% or more. Say.

As shown in FIG. 1, the electro-optical device 1 has a quadrangular shape in a plan view from the z-axis direction parallel to the thickness direction of the element substrate 2, but the plan-view shape of the electro-optical device 1 is not limited to this. However, it may be circular or the like, for example. Further, hereinafter, the plan view from the z-axis direction parallel to the thickness direction of the element substrate 2 is simply referred to as “plan view”. In the present embodiment, the z-axis direction is parallel to the optical axis direction of light.

As shown in FIG. 1, the element substrate 2 has a size including the counter substrate 3 in a plan view. As shown in FIG. 2, the element substrate 2 has a base material 21, a plurality of pixel electrodes 28, and an alignment film 29. The base material 21 is formed of a flat plate having translucency and insulation. The pixel electrode 28 is made of a transparent conductive material such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). The alignment film 29 is located closest to the liquid crystal layer 5 of the element substrate 2, and aligns the liquid crystal molecules of the liquid crystal layer 5. Examples of the constituent material of the alignment film 29 include polyimide and silicon oxide.

Although not shown in FIGS. 1 and 2, the TFT 25, the light shield 22 and the like are arranged between the base material 21 and the pixel electrode 28. The TFT 25, the light shield 22 and the like will be described later with reference to FIG.

As shown in FIG. 2, the counter substrate 3 includes a counter substrate substrate 31, an insulating layer 32, a common electrode 33, and an alignment film 34. The counter substrate substrate 31, the insulating layer 32, the common electrode 33, and the alignment film 34 are arranged in this order. The alignment film 34 is located closest to the liquid crystal layer 5.

The counter substrate substrate 31 is formed of a flat plate having translucency and insulation. The counter substrate substrate 31 is made of, for example, glass or quartz. The common electrode 33 is laminated on the counter substrate base material 31 via the insulating layer 32 formed of a translucent insulating material. The common electrode 33 is made of a transparent conductive material such as ITO or IZO. Further, the alignment film 34 aligns the liquid crystal molecules of the liquid crystal layer 5. Examples of the constituent material of the alignment film 34 include polyimide and silicon oxide.

The seal member 4 is formed using an adhesive or the like containing various curable resins such as epoxy resin. The seal member 4 is fixed to each of the element substrate 2 and the counter substrate 3.
A liquid crystal layer 5 is arranged in a region surrounded by the seal member 4, the element substrate 2 and the counter substrate 3. An injection port 41 for injecting a liquid crystal material containing liquid crystal molecules is formed in a part of the seal member 4, and the injection port 41 is sealed with a sealing material 40 formed of various resin materials. Be stopped.

The liquid crystal layer 5 includes liquid crystal molecules having positive or negative dielectric anisotropy. The liquid crystal layer 5 is sandwiched between the element substrate 2 and the counter substrate 3 so that liquid crystal molecules are in contact with both the alignment film 29 and the alignment film 34. The orientation of the liquid crystal molecules changes according to the voltage applied to the liquid crystal layer 5. The liquid crystal layer 5 enables gradation display by modulating light according to an applied voltage.

Further, as shown in FIG. 1, two scanning line driving circuits 61 and one signal line driving circuit 62 are arranged on the surface of the element substrate 2 on the side of the counter substrate 3. The signal line drive circuit 62 corresponds to a “circuit” that drives the TFT 25. Further, a plurality of external terminals 64 are arranged on the surface of the element substrate 2 facing the counter substrate 3. The external terminal 64 is connected to a wiring 65 routed from each of the scanning line driving circuit 61 and the signal line driving circuit 62.

The electro-optical device 1 has a display area A10 that overlaps the liquid crystal layer 5 in a plan view and displays an image and the like, and a peripheral area A20 that surrounds the display area A10 in a plan view. The display area A10 includes a plurality of pixels P arranged in a matrix. One pixel electrode 28 is arranged for one pixel P. The scanning line drive circuit 61, the signal line drive circuit 62, and the like described above are arranged in the peripheral region A20.

The driving method of the electro-optical device 1 is not particularly limited, but examples thereof include a TN (Twisted Nematic) mode and a VA (Vertical Alignment) mode.

1-1b. Electrical Configuration FIG. 3 is an equivalent circuit diagram showing the electrical configuration of the element substrate in the first embodiment. As shown in FIG. 3, on the element substrate 2, n scanning lines 261, m signal lines 262, and n capacitance lines 263 are formed. However, n and m are integers of 2 or more. The TFT 25 is arranged corresponding to each intersection of the n scanning lines 261 and the m signal lines 262.

The n scanning lines 261 shown in FIG. 3 are arranged at equal intervals in the y-axis direction and extend in the x-axis direction. The scanning line 261 is electrically connected to the TFT 25. The n scanning lines 261 are electrically connected to the scanning line driving circuit 61 shown in FIG. The scanning signals from the scanning line drive circuit 61 to the n scanning lines 261 are line-sequentially supplied to the scanning lines 261.

The m signal lines 262 shown in FIG. 3 are arranged at equal intervals in the x-axis direction and extend in the y-axis direction. The signal line 262 is electrically connected to the TFT 25. The m signal lines 262 are electrically connected to the signal line drive circuit 62 shown in FIG. Image signals S1, S2,..., And Sm are line-sequentially supplied to the signal line 262 from the signal line drive circuit 62 shown in FIG.

The n scanning lines 261 and the m signal lines 262 are insulated from each other and have a lattice shape in a plan view. A region surrounded by two adjacent scanning lines 261 and two adjacent signal lines 262 corresponds to the pixel P. One pixel electrode 28 is formed in one pixel P. The pixel electrode 28 is electrically connected to the TFT 25.

The n capacitance lines 263 are arranged at equal intervals in the y-axis direction and extend in the x-axis direction. The n capacitance lines 263 are insulated from the plurality of signal lines 262 and the plurality of scanning lines 261, and are formed apart from these. A fixed potential such as a ground potential is applied to the capacitance line 263.
Further, a storage capacitor 264 is arranged between the capacitance line 263 and the pixel electrode 28 in parallel with the liquid crystal capacitance in order to prevent leakage of charges held in the liquid crystal capacitance.

The scanning signals G1, G2,..., And Gn are sequentially activated, and when n scanning lines 261 are sequentially selected, the TFT 25 connected to the selected scanning line 261 is turned on. Then, the image signals S1, S2,..., And Sm having the magnitude corresponding to the gradation to be displayed are taken into the pixel P corresponding to the selected scanning line 261 via the m signal lines 262, and It is applied to the electrode 28. As a result, a voltage corresponding to the gradation to be displayed is applied to the liquid crystal capacitance formed between the pixel electrode 28 and the common electrode 33 of the counter substrate 3 shown in FIG. 2, and the liquid crystal is applied according to the applied voltage. The orientation of the molecules changes. The applied voltage is held by the storage capacitor 264. Light is modulated by such a change in the orientation of the liquid crystal molecules, and gradation display is possible.

1-1c. Configuration of Element Substrate in Display Area Next, the detailed configuration of the display area A10 of the element substrate 2 shown in FIG. 2 will be described. FIG. 4 is a partial plan view of the element substrate according to the first embodiment. FIG. 5 is a partial cross-sectional view of the element substrate in the first embodiment and is a cross-sectional view taken along the line BB in FIG. FIG. 6 is a cross-sectional view showing a light shield body included in the element substrate according to the first embodiment. FIG. 7 is a plan view showing a light shield provided in the element substrate according to the first embodiment. FIG. 8 is a plan view showing a TFT included in the element substrate according to the first embodiment.

The element substrate 2 shown in FIGS. 4 and 5 includes a base material 21, a plurality of light shields 22, a plurality of TFTs 25, a plurality of scanning lines 261, a plurality of signal lines 262, a plurality of capacitance lines 263, a plurality of storage capacitors 264, A plurality of pixel electrodes 28 and an alignment film 29 are provided. Note that the storage capacitor 264 and the alignment film 29 are not shown in FIG. Hereinafter, each part of the element substrate 2 will be sequentially described.

As shown in FIG. 5, the base material 21 is a flat plate provided with a concave portion 211 opening to the TFT 25 side. Examples of the constituent material of the base material 21 include a silicon-based inorganic compound. Specifically, the base material 21 is made of, for example, glass or quartz.

As shown in FIG. 6, a light shield 22 is embedded in the recess 211 of the base material 21. The light shield 22 has a property of blocking visible light. In the present specification, the light-shielding property means the light-shielding property with respect to visible light, and specifically, the transmittance of visible light is 10% or less, preferably 5% or less.

As shown in FIG. 7, the plurality of light shields 22 are arranged in a matrix in a plan view. The light shield 22 has a first portion 221 and a second portion 222. The second portion 222 has a rectangular shape along the +y axis direction in plan view. The first portion 221 has a longitudinal shape along the +y axis direction in a plan view and surrounds the second portion 222. The first portion 221 has a wide portion 2220 having a width wider than both ends in the +y axis direction in plan view. Further, as shown in FIG. 6, the thickness d1 of the first portion 221 is thinner than the thickness d2 of the second portion 222. The +z axis side surface 220 of the light shield 22 is located on the same plane as the +z axis side surface 210 of the base material 21, and the surface 210 and the surface 220 form the flat surface 200.

The constituent material of the light shield 22 is a metal such as tungsten (W), titanium (Ti), chromium (Cr), iron (Fe) and aluminum (Al), an alloy of metals, an alloy of metal and silicon. Examples thereof include metal silicides and metal compounds such as metal nitrides.

The first interlayer insulating layer 231 is arranged on the flat surface 200, and the TFT 25 is arranged on the first interlayer insulating layer 231. One TFT 25 is arranged as a pair with the above-mentioned one light shield 22. The TFT 25 has a semiconductor layer 250, a gate electrode 251, and a gate insulating film 252. The semiconductor layer 250 is disposed on the first interlayer insulating layer 231. Further, the gate insulating film 252 is interposed between the semiconductor layer 250 and the gate electrode 251.

As shown in FIG. 6, the semiconductor layer 250 has a channel region 2501, a source region 2502, a drain region 2503, a first LDD region 2504, and a second LDD region 2505. The source region 2502 functions as a “source electrode”. The drain region 2503 functions as a “drain electrode”. The channel region 2501 is located between the source region 2502 and the drain region 2503. The channel region 2501 overlaps with the gate electrode 251 in plan view. The first LDD region 2504 is located between the channel region 2501 and the source region 2502. The second LDD region 2505 is located between the channel region 2501 and the drain region 2503. Note that at least one of the first LDD region 2504 and the second LDD region 2505, particularly the first LDD region 2504, may be omitted.

The semiconductor layer 250 is formed by depositing polysilicon, for example. The region of the semiconductor layer 250 excluding the channel region 2501 is doped with an impurity that enhances conductivity. The impurity concentration in the first LDD region 2504 and the second LDD region 2505 is lower than the impurity concentration in the source region 2502 and the drain region 2503.

As shown in FIG. 8, the semiconductor layer 250 of the TFT 25 has a longitudinal shape along the +y axis direction in a plan view, and the longitudinal direction of the semiconductor layer 250 is parallel to the longitudinal direction of the light shield 22.
The TFT 25 overlaps the light shield 22 in a plan view. Since the TFT 25 and the light shield 22 overlap each other in plan view, the light can be blocked by the light shield 22, so that the incidence of light on the TFT 25 can be prevented or reduced.

Specifically, as shown in FIG. 6, the channel region 2501, the first LDD region 2504, and the second LDD region 2505 overlap the second portion 222 in a plan view. Here, when light is incident on the channel region 2501, the first LDD region 2504, and the second LDD region 2505, a malfunction due to a leak current of the TFT 25 is likely to occur. Therefore, it can be said that the channel region 2501, the first LDD region 2504, and the second LDD region 2505 are portions that particularly need the light shielding property. Therefore, as described above, the second portion 222, which is thicker than the first portion 221 and has a high light-shielding property, overlaps the channel region 2501, the first LDD region 2504, and the second LDD region 2505 in plan view, so that the leak current of the TFT 25 is reduced. It is possible to particularly effectively prevent malfunction due to. Note that the second LDD region 2505, the channel region 2501, and the first LDD region 2504 are likely to malfunction due to the leak current of the TFT 25 due to light.

The gate electrode 251 and the light shield 22 described above may be electrically connected. In this case, the light shield 22 can be used as a back gate. Further, in this case, although not shown, the contact that electrically connects the gate electrode 251 and the light shield 22 overlaps both the gate electrode 251 and the wide portion 2220 in a plan view, and the contact therebetween. Can be formed.

As shown in FIG. 5, the second interlayer insulating layer 232 is arranged on the semiconductor layer 250, and the third interlayer insulating layer 233 is arranged on the second interlayer insulating layer 232 so as to cover the gate electrode 251. It In addition, the scan line 261 is disposed on the third interlayer insulating layer 233. Further, a contact hole is provided in the third interlayer insulating layer 233, and a contact portion 241 that electrically connects the scanning line 261 and the gate electrode 251 is arranged in the contact hole.

A fourth interlayer insulating layer 234 is arranged on the third interlayer insulating layer 233 so as to cover the scanning line 261, and a capacitance line 263 is arranged on the fourth interlayer insulating layer 234. A fifth interlayer insulating layer 235 is arranged on the fourth interlayer insulating layer 234 so as to cover the capacitance line 263.

The storage capacitor 264 has a first capacitor 2641 and a second capacitor 2642. The first capacitor 2641 is arranged on the fifth interlayer insulating layer 235, and the sixth interlayer insulating layer 236 is arranged on the fifth interlayer insulating layer 235 so as to cover the first capacitor 2641. The second capacitor 2642 is disposed on the sixth interlayer insulating layer 236. A contact hole is provided in the sixth interlayer insulating layer 236, and a contact portion 242 that electrically connects the first capacitor 2641 and the second capacitor 2642 is arranged in the contact hole. Although not shown in detail, each of the first capacitor 2641 and the second capacitor 2642 includes two capacitor electrodes and a dielectric material arranged between these capacitor electrodes.

Further, a contact hole is provided in the fifth interlayer insulating layer 235, and a contact portion 243 for electrically connecting the first capacitor 2641 and the capacitor line 263 is arranged in the contact hole. Contact holes are provided in the second to sixth interlayer insulating layers 232 to 236, and a contact portion 244 electrically connecting the second capacitor 2642 and the drain region 2503 is arranged in the contact hole. Further, the drain region 2503 is electrically connected to the pixel electrode 28 via the contact portion 244, the storage capacitor 264, a contact (not shown), and the like.

A seventh interlayer insulating layer 237 is arranged on the sixth interlayer insulating layer 236 so as to cover the second capacitor 2642, and a signal line 262 is arranged on the seventh interlayer insulating layer 237. Further, as shown in FIG. 4, the intersection portion where the signal line 262 and the scanning line 261 intersect in plan view overlaps with the TFT 25. Further, as shown in FIG. 5, contact holes are provided in the second to seventh interlayer insulating layers 232 to 237, and the signal line 262 and the source region 2502 are electrically connected in the contact holes. The contact portion 245 is arranged.

The eighth interlayer insulating layer 238 is arranged on the seventh interlayer insulating layer 237 so as to cover the signal line 262, and the pixel electrode 28 is arranged on the eighth interlayer insulating layer 238. One pixel electrode 28 and the above-mentioned one TFT 25 are paired. An alignment film 29 is arranged on the pixel electrode 28.

The above-mentioned first to eighth interlayer insulating layers 231 to 238 are formed by using, for example, a silicon-based inorganic compound, and specifically, for example, a silicon thermal oxide film, a CVD (chemical vapor deposition) method, or the like. It is composed of a silicon oxide film formed by the vapor deposition method. In addition, examples of the respective constituent materials of the scanning line 261, the signal line 262, the capacitance line 263, and the capacitance electrode of the storage capacitance 264 include conductive materials such as polysilicon, metal, metal silicide, and metal compound. .. Further, each of the constituent materials of the contact portions 241-245 described above is also formed of a material having conductivity.

The above is the configuration of the element substrate 2 in the display area A10. As described above, the element substrate 2 contacts the light-transmitting pixel electrode 28, the light-transmitting base material 21, the TFT 25 which is a switching element electrically connected to the pixel electrode 28, and the base material 21. Then, the light shield 22 that overlaps the TFT 25 in a plan view from the thickness direction of the base material 21 is provided. As shown in FIG. 6, the light shield 22 has a first portion 221 and a second portion 222 whose thickness d2 is thicker than the thickness d1 of the first portion 221.

According to the element substrate 2, since the light shield 22 has the first portion 221 and the second portion 222 having different thicknesses from each other, warpage of the element substrate 2 and cracks of the light shield 22 are ensured while securing the light shielding property. Defects can be reduced. If the thickness of the entire light shield 22 is set to the thickness d2 in order to improve the light shielding property, the warp of the element substrate 2 becomes large due to the stress generated in the element substrate 2. On the contrary, if all the light shields 22 are set to have the thickness d1, the light shielding property becomes insufficient. Therefore, in the element substrate 2, the second portion 222 is arranged so as to overlap with the portion of the TFT 25 that particularly needs the light shielding property in plan view, and the second portion 222 that overlaps with the portion that needs the light shielding property but is less affected by light than the particularly required portion. Thus, the first portion 221 is arranged. By using such a light shield 22, it is possible to improve the light shielding property for the TFT 25 while reducing the occurrence of defects. As a result, the quality of the electro-optical device 1 can be improved.

Further, as described above, the TFT 25 has the gate electrode 251, the source region 2502 functioning as a “source electrode”, and the drain region 2503 functioning as a “drain electrode”. The second portion 222 is arranged between the source region 2502 and the drain region 2503 in plan view. The channel region 2501, the first LDD region 2504, and the second LDD region 2505 are located between the source region 2502 and the drain region 2503 in plan view. The channel region 2501, the first LDD region 2504, and the second LDD region 2505 are the portions that particularly need the light shielding property as described above. Therefore, by overlapping these with the second portion 222 in a plan view, it is possible to particularly effectively prevent malfunction due to the leak current of the TFT 25.

Note that, although the case where the source region 2502 functions as a “source electrode” is described in this embodiment, the “source electrode” is in contact with the source region 2502 of the contact portion 245 and overlaps with the source region 2502. You may think of it as a part. Similarly, in the present embodiment, the case where the drain region 2503 functions as a “drain electrode” is taken as an example, but a portion of the contact portion 244 that is in contact with the drain region 2503 and that overlaps with the drain region 2503 is referred to as a “drain electrode”. May be taken as ".

Further, as described above, the thickness d2 may be thicker than the thickness d1. Specifically, the thickness d1 can be 0.1 nm or more and 300 nm or less, and the thickness d2 can be the thickness d1+10 to 300 nm.

In addition, as described above, the base member 21 is provided with the concave portion 211 which is open to the TFT 25 side and in which the light shield 22 is arranged. By disposing the light shield 22 in the recess 211, as compared with the case where the light shield 22 is arranged so as to project from the surface 220 of the base material 21 toward the TFT 25 side, the light shield 22 is removed from the base material 21 during manufacturing, for example. Can be reduced. Therefore, the yield of the base material 21 can be increased.

The base material 21 may not have the recess 211. Further, the light shield 22 may be arranged so as to project from the surface 220.

Further, as described above, the flat surface 200 is configured by the surface 210 of the base material 21 on the TFT 25 side and the surface 220 of the light shield 22 on the TFT 25 side. Since the flat surface 200 is formed, there is no step between the surface 210 and the surface 220, and therefore light is not irregularly reflected at the step. Therefore, the possibility that light may enter the TFT 25 can be further reduced.

There may be a step between the surface 210 and the surface 220.

1-1d. Configuration of Element Substrate in Peripheral Region Next, a detailed configuration of the peripheral region A20 of the element substrate 2 shown in FIG. 2 will be described. FIG. 9 is a cross-sectional view showing the circuit light-shielding body included in the element substrate according to the first embodiment.

As shown in FIG. 9, the element substrate 2 has a circuit light shield 27 arranged in the peripheral region A20. The circuit light shield 27 is embedded in the recess 215 that is open on the +z-axis side of the element substrate 2. The +z-axis side surface 270 of the circuit light shield 27 is located on the same plane as the +z-axis side surface 220 of the substrate 21.

The circuit light shield 27 is arranged over almost the entire peripheral area A20 shown in FIGS. 1 and 2, and overlaps the scanning line driving circuit 61, the signal line driving circuit 62, the external terminal 64, and the wiring 65 in a plan view. .. Then, as shown in FIG. 9, the thickness d3 of the circuit light shield 27 is smaller than the thickness d2 of the second portion 222 of the light shield 22 described above. In addition, in the present embodiment, the thickness d3 of the circuit light shield 27 is equal to the thickness d1 of the first portion 221.

Since the thickness d3 is smaller than the thickness d2, the stress generated in the base material 21 by the circuit light shield 27 can be reduced as compared with the case where the thickness d3 is larger than the thickness d2.

The thickness d3 may be thicker or thinner than the thickness d1. Further, the thickness d3 may be thicker than the thickness d2. Further, the circuit light shield 27 may have a constant thickness or may have portions having different thicknesses. Further, the element substrate 2 may not have the circuit light shield 27.

1-1e. Method for Manufacturing Element Substrate Next, a method for manufacturing the element substrate 2 will be described. FIG. 10 is a flowchart showing the method for manufacturing the element substrate according to the first embodiment.

The manufacturing method of the element substrate 2 includes a base material forming step S11, a light shielding body forming step S12, a circuit light shielding body forming step S13, a wiring forming step S14, a pixel electrode forming step S15, and an alignment film forming step S16. Have and. The element substrate 2 is manufactured by sequentially performing each of these steps.
The light shielding body forming step S12 and the circuit light shielding body forming step S13 may be performed simultaneously or in parallel, or the light shielding body forming step S12 may be performed after the circuit light shielding body forming step S13.

11 and 12 are cross-sectional views for explaining the base material forming step in the first embodiment. First, in the base material forming step S11, for example, a flat plate made of a glass plate, a quartz plate, or the like is etched to form a first recess 2111 as shown in FIG. Then, the bottom of the first recess 2111 is further etched to form a second recess 2112 as shown in FIG. Through such formation, the concave portion 211 is formed in the base material 21. Further, in this step, although not shown in detail, the recess 215 shown in FIG. 9 is also formed.

13 and 14 are cross-sectional views for explaining the light-shielding body forming step in the first embodiment. Next, in the light shield formation step S12, a light shield composition containing a metal or the like is deposited in the recess 211 by a vapor deposition method such as a CVD method to form a light shield layer 22a as shown in FIG. .. Then, the light shielding layer 22a shown in FIG. 14 is formed by subjecting the light shielding layer 22a to flattening processing such as CMP (chemical mechanical polishing).
By performing polishing such as CMP, the flat surface 200 including the surface 220 of the light shield 22 and the surface 210 of the base material 21 can be easily formed.

Although not shown in detail, in the circuit light-shielding body forming step S13, the circuit light-shielding body 27 is formed by using the same method as the method in the light-shielding body forming step S12.

Although not shown in detail, in the wiring forming step S14, the TFT 25, the scanning line 261, the signal line 262, the capacitance line 263, the storage capacitance 264, and the first to eighth interlayer insulating layers 231 to 238 are formed, respectively. .. The TFT 25, the scanning line 261, the signal line 262, the capacitance line 263, and the capacitance electrode of the storage capacitance 264 are each formed with a metal film by, for example, a sputtering method or an evaporation method, and a resist mask is used for the metal film. Formed by etching. Each of the first to eighth interlayer insulating layers 231 to 238 is formed by forming an insulating film by a vapor deposition method or the like and subjecting the insulating film to a flattening process such as polishing such as CMP.

Although not shown in detail, in the pixel electrode forming step S15, the pixel electrode 28 is formed on the eighth interlayer insulating layer 238. The pixel electrode 28 is formed, for example, by forming a layer made of a transparent conductive material by a vapor deposition method such as a CVD method and then patterning the layer using a mask.

Although not shown in detail, in the alignment film forming step S16, for example, a layer made of polyimide is formed by a vapor deposition method such as a CVD method, and then a rubbing process is performed to form the alignment film 29.

As described above, the element substrate 2 shown in FIG. 4 can be formed. Further, the counter substrate 3 is formed by appropriately using, for example, a known technique, and the element substrate 2 and the counter substrate 3 are connected via the seal member 4. After that, a liquid crystal material is injected between the element substrate 2, the counter substrate 3, and the sealing member 4 to form a liquid crystal layer 5, and then the liquid crystal layer 5 is sealed. Further, various circuits and the like are formed as appropriate. In this way, the electro-optical device 1 shown in FIGS. 1 and 2 can be manufactured.

As described above, in the manufacture of the element substrate 2, the concave portion 211 including the first concave portion 2111 and the second concave portion 2112 is formed in the base material 21, and the light shielding composition is deposited on the concave portion 211 to form the light shielding layer 22a. The light shielding body 22 is formed by a method of forming and then performing a flattening process such as CMP. That is, the light shield 22 is formed by using the so-called dual damascene method. By using the dual damascene method, the flat surface 200 can be easily formed and the smoothness of the flat surface 200 can be improved. Further, by using the dual damascene method, for example, as compared with a method of forming a light shielding film by forming a light shielding film on the substrate 21 without forming the recess 211 in the substrate 21 and etching the light shielding film. Therefore, cracks and the like of the light shield 22 can be reduced. That is, the crack resistance of the light shield 22 can be enhanced by using the dual damascene method.

Further, in the element substrate 2 having a plurality of pixel electrodes 28 and TFTs 25, in order to form a small and high quality element substrate 2, the light shield 22 is desired to be fine and have excellent shape accuracy. According to the dual damascene method described above, it is possible to form the light shield 22 that is fine and has excellent shape accuracy.

1-2. Second Embodiment Next, a second embodiment of the present invention will be described. FIG. 15 is a plan view showing a light shield body included in the element substrate according to the second embodiment.

The present embodiment is mainly the same as the first embodiment except that the configuration of the light shield is different. In the following description, the second embodiment will be described focusing on the differences from the first embodiment, and the description of the same matters will be omitted. Further, in FIG. 15, the same components as those in the first embodiment are designated by the same reference numerals.

The element substrate 2A shown in FIG. 15 has a connecting portion 223 that connects adjacent light shields 22. In the present embodiment, the plurality of light shields 22 arranged along the +x axis direction are connected to the adjacent light shields 22 by the connecting portion 223. Specifically, the light shield 22 located in the upper left of FIG. 15 and the light shield 22 located in the upper right of FIG. 15 are connected by the connecting portion 223. Further, the light shield 22 located at the lower left in FIG. 15 and the light shield 22 located at the lower right in FIG. 15 are connected by the connecting portion 223.

As shown in the figure, since the adjacent light shields 22 are connected to each other by the connecting portion 223, if the light shield 22 and the gate electrode 251 of the TFT 25 are electrically connected, the plurality of light shields 22 and the plurality of connecting portions are formed. 223 can be used as the scan line.

According to the present embodiment as well, similar to the first embodiment, it is possible to improve the light blocking effect on the TFT 25 while reducing the occurrence of defects in the element substrate 2A.

1-3. Third Embodiment Next, a third embodiment of the present invention will be described. FIG. 16 is a cross-sectional view showing a light shield body included in the element substrate according to the third embodiment.

The present embodiment is mainly the same as the first embodiment except that the configuration of the light shield is different. In the following description, the third embodiment will be described focusing on the differences from the first embodiment, and the description of the same matters will be omitted. Further, in FIG. 16, the same components as those in the first embodiment are designated by the same reference numerals.

The light shield 22B included in the element substrate 2B shown in FIG. 16 is disposed between the metal film 225 containing tungsten and the metal film 225 and the base material 21, and is made of tungsten nitride (WN) or titanium nitride (TiN). And a metal nitride film 226 containing the same.

Since the light shield 22B has the metal nitride film 226, the adhesiveness between the light shield 22B and the base material 21 can be enhanced as compared with the case where the light shield 22B does not have the metal nitride film 226. Further, since the metal film 225 containing tungsten is provided, the light blocking effect of the light blocking member 22B can be improved.

Here, the film made of tungsten nitride or titanium nitride is crystallized by heat treatment during manufacturing, and the OD (Optical Dencity) value is likely to decrease. On the other hand, the film made of tungsten has excellent heat resistance, and the OD value is not easily lowered even by the heat treatment during manufacturing. Therefore, by providing the metal film 225 containing tungsten, for example, it is possible to suppress a decrease in the OD value such as heat treatment during manufacturing, and thus it is possible to improve the light blocking effect of the light blocking body 22B.

According to the present embodiment as well, similar to the first embodiment, it is possible to reduce the occurrence of defects in the element substrate 2B and improve the light shielding property for the TFT 25.

1-4. Fourth Embodiment Next, a fourth embodiment of the present invention will be described. FIG. 17 is a cross-sectional view showing a light shield body included in the element substrate according to the fourth embodiment.

This embodiment is the same as the third embodiment except that the light shield body is mainly provided with a tungsten silicide film. In the following description, the fourth embodiment will be described focusing on the differences from the third embodiment, and the description of the same matters will be omitted. Further, in FIG. 17, the same components as those in the third embodiment are designated by the same reference numerals.

The light shield 22C included in the element substrate 2C shown in FIG. 17 is disposed between the metal nitride film 226 and the base material 21 and has a tungsten silicide film 227 containing tungsten silicide (WSi).

Since the light shield 22C has the tungsten silicide film 227, the adhesion between the light shield 22C and the base material 21 can be improved as compared with the case where the tungsten silicide film 227 is not provided. In particular, the base material 21 whose constituent material is a silicon-based inorganic compound has high adhesion to the tungsten silicide film 227 containing silicon atoms. Further, the metal nitride film 226 functions as a barrier layer for preventing the tungsten silicide contained in the tungsten silicide film 227 from diffusing into the metal film 225. Therefore, the decrease in the OD value of the metal film 225 can be suppressed. Therefore, by having the tungsten silicide film 227, the adhesion to the base material 21 and the OD value can be further enhanced as compared with the case where the tungsten silicide film 227 is not provided.

The metal film 225 may contain a metal other than the above-mentioned metals, for example, about 5%. Further, the metal nitride film 226 and the tungsten silicide film 227 may each contain a material other than the above-mentioned materials, for example, about 5%.

According to the present embodiment as well, similar to the third embodiment, it is possible to improve the light blocking effect on the TFT 25 while reducing the occurrence of defects in the element substrate 2C.

1-5. Fifth Embodiment Next, a fifth embodiment of the present invention will be described. FIG. 18 is a cross-sectional view showing a light shield body included in the element substrate according to the fifth embodiment. FIG. 19 is a plan view showing a light shield body included in the element substrate according to the fifth embodiment.

This embodiment is mainly the same as the fourth embodiment except the shape of the light shield. In the following description, the fifth embodiment will be described focusing on the differences from the fourth embodiment, and the description of the same matters will be omitted. 18 and 19, the same components as those in the fourth embodiment are designated by the same reference numerals.

The outer shape of the light shield 22C in the fourth embodiment has an inside angle of 90°, but the outer shape of the light shield 22D included in the element substrate 2D shown in FIGS. 18 and 19 has rounded corners. Further, as shown in FIG. 19, the plan view shape of the second portion 222D included in the light shield 22D is similar to the plan view shape of the first portion 221D. Further, the thickness of the first portion 221D is thinner than the thickness of the second portion 222D. Even with the light shield 22D having such a shape, it is possible to improve the light-shielding property and reduce the warp of the element substrate 2D and the like, similarly to the light shield 22C in the fourth embodiment.

According to the present embodiment as well, similar to the fourth embodiment, it is possible to improve the light blocking effect on the TFT 25 while reducing the occurrence of defects in the element substrate 2D.

2. Electronic Device The electro-optical device 1 can be used in various electronic devices.

FIG. 20 is a perspective view showing a personal computer which is an example of an electronic device. The personal computer 2000 includes the electro-optical device 1 that displays various images, and a main body 2010 in which a power switch 2001 and a keyboard 2002 are installed.

FIG. 21 is a perspective view showing a smartphone which is an example of an electronic device. The smartphone 3000 has operation buttons 3001 and the electro-optical device 1 that displays various images. The screen content displayed on the electro-optical device 1 is changed according to the operation of the operation button 3001.

FIG. 22 is a schematic diagram showing a projector which is an example of an electronic device. The projection display device 4000 is, for example, a three-plate type projector. The electro-optical device 1R is the electro-optical device 1 corresponding to the red display color, the electro-optical device 1G is the electro-optical device 1 corresponding to the green display color, and the electro-optical device 1B is the blue display color. The electro-optical device 1 corresponds to. That is, the projection display device 4000 has three electro-optical devices 1R, 1G, and 1B that respectively correspond to red, green, and blue display colors.

The illumination optical system 4001 supplies the red component r to the electro-optical device 1R, the green component g to the electro-optical device 1G, and the blue component b to the electro-optical device 1B of the light emitted from the illumination device 4002 as the light source. Supply to. Each electro-optical device 1R, 1G, 1B functions as an optical modulator such as a light valve that modulates each monochromatic light supplied from the illumination optical system 4001 according to a display image. The projection optical system 4003 combines the lights emitted from the electro-optical devices 1R, 1G, and 1B and projects the combined lights on the projection surface 4004.

The personal computer 2000, the smartphone 3000, and the projection display device 4000 described above each include the electro-optical device 1 having the above-described excellent quality. By providing the electro-optical device 1, the display uniformity of the personal computer 2000, the smartphone 3000, and the projection display device 4000 can be improved. Therefore, the quality of the personal computer 2000, the smartphone 3000, and the projection display device 4000 can be improved.

It should be noted that the electronic device to which the present invention is applied is not limited to the illustrated device, and examples thereof include PDAs (Personal Digital Assistants), digital still cameras, televisions, video cameras, car navigation devices, in-vehicle displays, and electronic devices. A notebook, an electronic paper, a calculator, a word processor, a workstation, a videophone, a POS (Point of sale) terminal, etc. are mentioned. Further, examples of electronic devices to which the present invention is applied include devices such as printers, scanners, copiers, video players, and touch panels.

Although the electro-optical device and the electronic apparatus of the invention have been described above based on the preferred embodiments, the invention is not limited to the above-described embodiments. Further, the configuration of each part of the present invention can be replaced with an arbitrary configuration that exhibits the same function as that of the above-described embodiment, and an arbitrary configuration can be added.

Further, in the above description, the liquid crystal device has been described as an example of the electro-optical device of the invention, but the electro-optical device of the invention is not limited to this. That is, any electro-optical device whose optical characteristics change depending on electric energy may be used. For example, the present invention can be applied to a display panel using a light emitting element such as an organic EL (electro luminescence), an inorganic EL, or a light emitting polymer as in the above-described embodiment.

Further, the present invention can be applied to the electrophoretic display panel using microcapsules containing a colored liquid and white particles dispersed in the liquid, as in the above-described embodiment.

Further, in the above description, an example of the switching element is a TFT, but the switching element is not limited to this, and may be, for example, a MOSFET (metal-oxide-semiconductor field-effect transistor).

Further, the electro-optical device of the invention is not limited to the transmissive type and may be a reflective type.

DESCRIPTION OF SYMBOLS 1... Electro-optical device, 21... Base material, 22... Light-shielding body, 27... Circuit light-shielding body, 28... Pixel electrode, 61... Scan line drive circuit, 200... Flat surface, 211... Recessed part, 221... 1st part, 222... Second part, 225... Metal film, 226... Metal nitride film, 227... Tungsten silicide film, 2501... Channel region, 2502... Source region, 2503... Drain region, 2504... First LDD region, 2505... Second LDD region

Claims (8)

A translucent base material,
A transparent pixel electrode,
A switching element electrically connected to the pixel electrode,
A light-shielding body which is in contact with the base material and which overlaps with the switching element in a plan view from the thickness direction of the base material,
The electro-optical device, wherein the light shield has a first portion and a second portion having a thickness larger than the thickness of the first portion. The electro-optical device according to claim 1, wherein the base member is provided with a concave portion that is opened toward the switching element and in which the light shield is disposed. The electro-optical device according to claim 2, wherein the surface of the base material on the switching element side and the surface of the light shield on the switching element side form a flat surface. 4. The light shield comprises a metal film containing tungsten and a metal nitride film containing tungsten nitride or titanium nitride, which is disposed between the metal film and the base material. The electro-optical device according to the item. The electro-optical device according to claim 4, wherein the light shield is disposed between the metal nitride film and the base material and includes a tungsten silicide film containing tungsten silicide. The switching element has a gate electrode, a source electrode, and a drain electrode,
The electro-optical device according to claim 1, wherein the second portion is disposed between the source electrode and the drain electrode in a plan view from the thickness direction of the base material. A circuit for driving the switching element,
In a plan view from the thickness direction of the base material, a circuit light shield that overlaps the circuit,
The electro-optical device according to claim 1, wherein the thickness of the circuit light shield is smaller than the thickness of the second portion. An electronic apparatus comprising the electro-optical device according to claim 1.

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