JP6146441B2 - Electro-optical device and electronic apparatus - Google Patents

Description

  The present invention relates to a technical field of an electro-optical device such as a liquid crystal device, an electronic apparatus such as a liquid crystal projector including the electro-optical device, and a method of manufacturing the electro-optical device.

  As this type of electro-optical device, for example, a substrate is provided with a pixel electrode, a scanning line for selectively driving the pixel electrode, a data line, and a TFT (Thin Film Transistor) for pixel switching. Some perform active matrix driving. Switching elements such as TFTs and various wirings are formed as a laminated structure on the substrate.

  In the electro-optical device as described above, a storage capacitor is formed in a laminated structure, thereby reducing black unevenness (that is, improving contrast) in a display image and preventing a reduction in pixel life. For example, Patent Document 1 proposes a technique for realizing a storage capacitor having excellent withstand voltage performance by disposing two electrodes including an oxide film so as to face each other via a dielectric film.

JP 2005-55661 A

  In a TFT used as a switching element, for example, when a light source light projected from a light source is reflected during operation of the apparatus and is incident, light leakage current is generated. Since the light leakage current may cause a malfunction of the device, it is desirable that the light shielding performance of the TFT is as high as possible.

  However, in the technique according to Patent Document 1, the layer existing on the upper layer side of the TFT is an electrode layer of an oxide film that constitutes a storage capacitor, and thus the light shielding performance of the TFT cannot be said to be sufficient. That is, the above-described technique has a technical problem that it is impossible to reliably prevent the occurrence of light leakage current in the TFT.

  The present invention has been made in view of, for example, the above-described problems. An electro-optical device and an electronic apparatus that have a high storage capacity and can realize high light-shielding performance with respect to a TFT, and a method for manufacturing the electro-optical device. The issue is to provide.

  In order to solve the above problems, a first electro-optical device of the present invention is provided corresponding to the pixel electrode between a pixel electrode provided for each pixel on the substrate and the substrate and the pixel electrode. A transistor, a first capacitor electrode provided between the pixel electrode and the transistor and electrically connected to the pixel electrode and the transistor, and between the pixel electrode and the first capacitor electrode, The transistor is at least partially disposed between the pixel electrode and the second capacitor electrode, which is disposed opposite to the first capacitor electrode via a capacitor insulating film, and is supplied with a predetermined potential. And a light-shielding film electrically connected to the second capacitor electrode through a contact hole opened in an insulating film disposed between the second capacitor electrode and the second capacitor electrode.

  The first electro-optical device according to the present invention includes, for example, an element substrate provided with a pixel electrode and a transistor such as a pixel switching TFT electrically connected to the pixel electrode, and a counter electrode facing the pixel electrode. An electro-optical material such as liquid crystal is sandwiched between the counter substrate provided. During the operation of the electro-optical device, an image signal is selectively supplied to the pixel electrode, whereby image display is performed in a pixel region (or image display region) in which a plurality of pixel electrodes are arranged. The image signal is supplied from the data line to the pixel electrode at a predetermined timing, for example, when a transistor electrically connected between the data line and the pixel electrode is turned on / off.

  In the first electro-optical device of the present invention, the first capacitor electrode is electrically connected to the pixel electrode and the transistor provided between the substrate and the pixel electrode. Specifically, the first capacitor electrode is provided between the pixel electrode and the transistor. For example, the drain region of the transistor and the first capacitor electrode are electrically connected via a contact hole or a relay layer, and the first capacitor electrode is connected to the first capacitor electrode. The capacitor electrode and the pixel electrode are electrically connected through another contact hole or a relay layer. That is, the first capacitor electrode relays electrical conduction between the pixel electrode and the transistor.

  On the upper layer side of the first capacitor electrode, a second capacitor electrode is disposed opposite to the capacitor electrode through a capacitor insulating film. A predetermined potential is supplied to the second capacitor electrode through a light shielding film described later. Thereby, the second capacitor electrode is set to a constant potential. Accordingly, the first capacitor electrode and the second capacitor electrode arranged so as to sandwich the capacitor insulating film are configured as a storage capacitor that temporarily holds the potential of the pixel electrode.

  A light shielding film is provided between the second capacitor electrode and the pixel electrode at a position at least partially overlapping the transistor. The light shielding film is formed including a material having a light shielding performance higher than that of, for example, the first capacitor electrode and the second capacitor electrode, and shields light that is about to enter the transistor from the upper layer side. The light shielding film is provided so as to be electrically connected to the second capacitor electrode. The light shielding film is formed, for example, on an interlayer insulating film formed on the second capacitor electrode, and is electrically connected to the second capacitor electrode through a contact hole formed in the interlayer insulating film. A predetermined potential is supplied to the light shielding film via a capacitor line or the like, and as described above, this predetermined potential is supplied to the second capacitor electrode via the light shielding film.

  Here, if the above-described light-shielding film is not provided, light that should not be incident on the transistor may be incident, which may cause a light leakage current. This light leakage current causes the device to malfunction.

  However, in the present invention, since the light shielding performance of the transistor is particularly enhanced by the light shielding film, generation of light leakage current can be prevented, and a highly reliable device can be realized. Typically, the first capacitor electrode and the second capacitor electrode are also formed by including a light-shielding material and function as a member for improving the light-shielding performance for the transistor. By providing the light shielding film according to the present invention, the light shielding performance can be further improved.

  As described above, according to the first electro-optical device of the present invention, the storage capacitor can be formed by the first capacitor electrode and the second capacitor electrode, and the light shielding film has high light shielding performance for the transistor. Can be realized.

  In order to solve the above-described problem, a second electro-optical device according to the present invention is provided with a pixel electrode provided for each pixel on a substrate, and provided between the substrate and the pixel electrode so as to correspond to the pixel electrode. A transistor, a first capacitor electrode provided between the pixel electrode and the transistor, and electrically connected to the pixel electrode and the transistor, and between the pixel electrode and the first capacitor electrode; A second capacitor electrode, which is disposed opposite to the first capacitor electrode with a first capacitor insulating film interposed therebetween, and is supplied with a predetermined potential, and between the pixel electrode and the second capacitor electrode, A contact hole that is provided so as to at least partially overlap, is disposed to face the second capacitor electrode via a second capacitor insulating film, and is opened in the insulating film disposed between the pixel electrode. Before And a light shielding film being electrically connected to the pixel electrode.

  The second electro-optical device according to the present invention includes, for example, an element substrate provided with a pixel electrode and a transistor such as a pixel switching TFT electrically connected to the pixel electrode, and a counter electrode facing the pixel electrode. An electro-optical material such as liquid crystal is sandwiched between the counter substrate provided. During the operation of the electro-optical device, an image signal is selectively supplied to the pixel electrode, whereby image display is performed in a pixel region (or image display region) in which a plurality of pixel electrodes are arranged. The image signal is supplied from the data line to the pixel electrode at a predetermined timing, for example, when a transistor electrically connected between the data line and the pixel electrode is turned on / off.

  In the second electro-optical device of the present invention, the first capacitor electrode is electrically connected to the pixel electrode and the transistor provided between the substrate and the pixel electrode. Specifically, the first capacitor electrode is provided between the pixel electrode and the transistor. For example, the drain region of the transistor and the first capacitor electrode are electrically connected via a contact hole or a relay layer, and the first capacitor electrode is connected to the first capacitor electrode. The capacitor electrode and the pixel electrode are electrically connected through another contact hole or a relay layer. That is, the first capacitor electrode relays electrical conduction between the pixel electrode and the transistor.

  On the upper layer side of the first capacitor electrode, a second capacitor electrode is disposed opposite to the first capacitor electrode with a first capacitor insulating film interposed therebetween. A predetermined potential is supplied to the second capacitor electrode through, for example, a capacitor line. Thereby, the second capacitor electrode is set to a constant potential. Accordingly, the first capacitor electrode and the second capacitor electrode arranged so as to sandwich the capacitor insulating film are configured as a storage capacitor that temporarily holds the potential of the pixel electrode.

  A light shielding film is provided between the second capacitor electrode and the pixel electrode at a position at least partially overlapping the transistor. The light shielding film is formed including a material having a light shielding performance higher than that of, for example, the first capacitor electrode and the second capacitor electrode, and shields light that is about to enter the transistor from the upper layer side.

  Here, if the above-described light-shielding film is not provided, light that should not be incident on the transistor may be incident, which may cause a light leakage current. This light leakage current causes the device to malfunction.

  However, in the present invention, since the light shielding performance of the transistor is particularly enhanced by the light shielding film, generation of light leakage current can be prevented, and a highly reliable device can be realized. Typically, the first capacitor electrode and the second capacitor electrode are also formed by including a light-shielding material and function as a member for improving the light-shielding performance for the transistor. By providing the light shielding film according to the present invention, the light shielding performance can be further improved.

  The light shielding film according to the present invention is further provided so as to be opposed to the second capacitor electrode through the second capacitor insulating film, and is electrically connected to the pixel electrode through the contact hole opened in the insulating film. Connected. By being electrically connected to the pixel electrode, the light shielding film has the same potential as the first capacitor electrode. Therefore, the second capacitor electrode and the light-shielding film disposed to face each other via the second capacitor insulating film are configured as a storage capacitor that temporarily holds the potential of the pixel electrode, similarly to the first capacitor electrode and the second capacitor electrode. Is done. According to such a configuration, two different storage capacitors can be configured in the same plane. Therefore, it is possible to realize an extremely high density storage capacity.

  As described above, according to the second electro-optical device of the present invention, a high-capacity storage capacitor can be formed by the first capacitor electrode, the second capacitor electrode, the second capacitor electrode, and the light shielding film. In addition, high light shielding performance for the transistor can be realized by the light shielding film.

  In one aspect of the electro-optical device of the present invention, the light-shielding film is provided in a region inside the region where the second capacitor electrode is provided as viewed in plan on the substrate.

  According to this aspect, since the light shielding film is formed in a narrower range than the second capacitance electrode (in other words, the conductive layer located on the lower layer side of the light shielding film), the processing of the light shielding film is facilitated. Specifically, for example, when patterning the light shielding film by etching or the like, it is not necessary to consider the case where even the member on the lower layer side is scraped. Therefore, the manufacturing process of the device can be simplified.

  In another aspect of the electro-optical device of the present invention, the second capacitor electrode has an oxide film formed on a surface thereof.

  According to this aspect, since the oxide film is formed on the surface of the second capacitor electrode, the pressure resistance performance is improved. Therefore, a more reliable device can be realized. The oxide film is formed, for example, by patterning the second capacitor electrode and then performing an oxidation process to partially oxidize the surface of the second capacitor electrode.

  In another aspect of the electro-optical device according to the aspect of the invention, the transistor includes an LDD (Lightly Doped Drain) region so as to sandwich a channel layer, and the second capacitor electrode and the light-shielding film are formed in the transistor. They are electrically connected to each other through a contact hole provided so as to at least partially overlap the LDD region on the pixel electrode side.

  According to this aspect, the transistor has an LDD structure. More specifically, the semiconductor layer included in the transistor includes a source region electrically connected to the data line, a drain region electrically connected to the pixel electrode, and a channel region disposed to face the gate electrode. A data line side LDD region provided between the source region and the channel region, and a pixel electrode side LDD region provided between the drain region and the channel region.

  In this embodiment, in particular, the light shielding film is provided on, for example, an interlayer insulating film laminated on the second capacitor electrode, and the second capacitor electrode and the light shielding film are LDDs on the pixel electrode side of the transistor in the interlayer insulating film. They are electrically connected to each other through a contact hole provided so as to at least partially overlap the region. Therefore, a part of the light shielding film provided along the contact hole is formed on the lower layer side (that is, the transistor side). As a result, the light shielding film can exhibit a light shielding function at a closer position in a region overlapping with the LDD region on the pixel electrode side where light leakage is relatively likely to occur among the respective portions of the transistor. Therefore, the light shielding performance for the transistor can be improved efficiently.

  In another aspect of the electro-optical device according to the aspect of the invention, the predetermined potential is a counter common potential supplied to a counter electrode disposed to face the pixel electrode via an electro-optical material.

  According to this aspect, the counter common potential supplied to the counter electrode is supplied to the second capacitor electrode. Therefore, it is possible to configure the storage capacitor without separately providing a power source for supplying a potential to the second capacitor electrode. Therefore, it is possible to prevent the device configuration from becoming complicated and the cost from increasing.

  In another aspect of the electro-optical device according to the aspect of the invention, the first capacitor electrode is electrically connected to the pixel electrode through a relay layer provided in the same layer as the gate electrode of the transistor.

  According to this aspect, by using the relay layer provided in the same layer as the gate electrode, electrical conduction between the first capacitor electrode and the pixel electrode can be realized with a relatively simple configuration. Note that the relay layer in this embodiment is a layer electrically separated from the gate electrode, and the “same layer” means a layer formed by the same film forming process.

  In order to solve the above problems, an electronic apparatus according to the present invention includes the above-described electro-optical device according to the present invention (including various aspects thereof).

  According to the electronic apparatus of the present invention, the electro-optical device according to the present invention described above is provided, so that the projection display device, the television set, and the mobile phone can display with high reliability and high quality. Various electronic devices such as electronic notebooks, word processors, viewfinder type or monitor direct view type video tape recorders, workstations, videophones, POS terminals and touch panels can be realized. In addition, as an electronic apparatus of the present invention, for example, an electrophoretic device such as electronic paper can be realized.

  In order to solve the above problems, a method for manufacturing an electro-optical device according to the present invention includes a pixel electrode forming step of forming a pixel electrode for each pixel on a substrate and a transistor forming step of forming a transistor corresponding to the pixel electrode And a first capacitor electrode forming step of forming a first capacitor electrode so as to be electrically connected to the pixel electrode and the transistor, respectively, and an upper layer side of the first capacitor electrode opposed to each other via a capacitor insulating film A second capacitor electrode forming step of forming a second capacitor electrode, a patterning step of patterning the first capacitor electrode and the second capacitor electrode using the same mask, and after the patterning step, An oxidation treatment step for oxidizing the first capacitance electrode and the second capacitance electrode, and after the oxidation treatment step, at least the transistor in the upper layer of the second capacitance electrode And a light shielding film forming step of forming a light shielding film to partially overlap position.

  According to the method for manufacturing an electro-optical device of the present invention, a pixel electrode and a transistor are formed on the substrate so as to correspond to the pixel electrode. Note that the pixel electrode is typically formed in the uppermost layer of the laminated structure after the members described later are laminated. That is, each process of the present invention may be performed by replacing each process unless the order is mentioned.

  The first capacitor electrode is formed to be connected to each of the pixel electrode and the transistor. A second capacitor electrode is formed on the upper layer side of the first capacitor electrode so as to face each other with a capacitor insulating film interposed therebetween. The first capacitor electrode and the second capacitor electrode that are arranged to face each other via the capacitor insulating film are configured as a storage capacitor that temporarily holds the potential of the pixel electrode.

  Here, particularly in the present invention, the first capacitor electrode and the second capacitor electrode are patterned using the same mask. That is, the first capacitor electrode and the second capacitor electrode are patterned together. The patterned first capacitor electrode and second capacitor electrode are subjected to oxidation treatment. Thereby, it is possible to improve the pressure resistance performance of the first capacitor electrode and the second capacitor electrode.

  Subsequently, a light shielding film is formed on the second capacitor electrode at a position at least partially overlapping the transistor. In other words, the light shielding film is formed after the oxidation treatment is performed on the first capacitor electrode and the second capacitor electrode constituting the storage capacitor. The light shielding film is formed, for example, including a material having a light shielding performance higher than that of the first capacitor electrode and the second capacitor electrode, and shields light that is about to enter the transistor from the upper layer side.

  Here, if an oxidation treatment is performed on a high melting point metal having a high light shielding property, contamination of the processing apparatus and cracks due to stress frequently occur, which is not preferable in practice. However, in the present invention, as described above, the light shielding film is formed after the oxidation treatment is performed on the members constituting the storage capacitor. That is, the oxidation treatment is not performed on the light shielding film. Therefore, the practical inconvenience as described above can be avoided.

  As described above, according to the method for manufacturing an electro-optical device of the present invention, it is possible to manufacture an electro-optical device that has a storage capacitor and can realize high light-shielding performance for a transistor.

  In one aspect of the method for manufacturing an electro-optical device according to the present invention, an interlayer insulating film forming step of forming an interlayer insulating film having a thickness smaller than that of the second capacitor electrode and the light shielding film on the second capacitor electrode; A contact hole forming step of forming a contact hole in the interlayer insulating film, wherein the light shielding film is electrically connected to the second capacitor electrode through the contact hole in the light shielding film forming step. It is formed.

  According to this aspect, since the light-shielding film and the second capacitor electrode are electrically connected via the contact hole, the light-shielding film positioned on the upper layer side is set to the potential for making the second capacitor electrode constant. It becomes possible to supply via. Further, since the interlayer insulating film formed between the light shielding film and the second capacitor electrode is thinner than the light shielding film and the second capacitor electrode, the light shielding film is formed on the lower layer side (in other words, on the transistor side). be able to. Therefore, the light shielding performance for the transistor can be further increased.

  The effect | action and other gain of this invention are clarified from the form for implementing invention demonstrated below.

1 is a plan view showing an overall configuration of an electro-optical device according to a first embodiment. It is the HH 'sectional view taken on the line of FIG. FIG. 3 is an equivalent circuit diagram of various elements and wirings in a plurality of pixels of the electro-optical device according to the first embodiment. 3 is a plan view transparently showing the arrangement of conductive layers around the TFT of the electro-optical device according to the first embodiment. FIG. FIG. 5 is a cross-sectional view taken along line A-A ′ of FIG. 4. FIG. 5 is a sectional view taken along line B-B ′ of FIG. 4. FIG. 10 is a plan view transparently showing the arrangement of conductive layers around a TFT of an electro-optical device according to a second embodiment. FIG. 8 is a cross-sectional view taken along line C-C ′ of FIG. 7. FIG. 8 is a sectional view taken along line D-D ′ in FIG. 7. FIG. 10 is a cross-sectional view illustrating a modification of the electro-optical device according to the second embodiment. FIG. 6 is a process cross-sectional view (part 1) illustrating the manufacturing process of the electro-optical device according to the embodiment in order. FIG. 10 is a process cross-sectional view (part 2) illustrating the manufacturing process of the electro-optical device according to the embodiment in order. FIG. 10 is a process cross-sectional view (part 3) illustrating the manufacturing process of the electro-optical device according to the embodiment in order. FIG. 10 is a process cross-sectional view (part 4) illustrating the manufacturing process of the electro-optical device according to the embodiment in order. FIG. 10 is a process cross-sectional view (part 5) illustrating the manufacturing process of the electro-optical device according to the embodiment in order. FIG. 10 is a process cross-sectional view (part 6) illustrating the manufacturing process of the electro-optical device according to the embodiment in order. It is a top view which shows the structure of the projector which is an example of the electronic device to which the electro-optical apparatus is applied.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Electro-optical device>
An electro-optical device according to this embodiment will be described with reference to FIGS. In the following embodiments, a TFT active matrix driving type liquid crystal device with a built-in driving circuit will be described as an example of the electro-optical device of the present invention.

<First Embodiment>
First, the overall configuration of the electro-optical device according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a plan view showing the overall configuration of the electro-optical device according to this embodiment, and FIG. 2 is a cross-sectional view taken along the line HH ′ of FIG.

  1 and 2, in the electro-optical device according to the present embodiment, a TFT array substrate 10 and a counter substrate 20 are disposed to face each other. The TFT array substrate 10 is, for example, a transparent substrate such as a quartz substrate or a glass substrate, a silicon substrate, or the like. The counter substrate 20 is a transparent substrate such as a quartz substrate or a glass substrate. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20. The liquid crystal layer 50 is made of, for example, a liquid crystal in which one or several types of nematic liquid crystals are mixed, and takes a predetermined alignment state between a pair of alignment films.

  The TFT array substrate 10 and the counter substrate 20 are bonded to each other by a sealing material 52 provided in a sealing region located around the image display region 10a provided with a plurality of pixel electrodes.

  The sealing material 52 is made of, for example, an ultraviolet curable resin, a thermosetting resin, or the like for bonding the two substrates, and is applied on the TFT array substrate 10 in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like. It is. In the sealing material 52, a gap material such as glass fiber or glass beads for dispersing the distance between the TFT array substrate 10 and the counter substrate 20 (that is, the inter-substrate gap) to a predetermined value is dispersed. Note that the gap material may be arranged in the image display region 10a or a peripheral region located around the image display region 10a in addition to or instead of the material mixed in the seal material 52.

  A light-shielding frame light-shielding film 53 that defines the frame area of the image display area 10a is provided on the counter substrate 20 side in parallel with the inside of the seal area where the sealing material 52 is disposed. A part or all of the frame light shielding film 53 may be provided as a built-in light shielding film on the TFT array substrate 10 side.

  A data line driving circuit 101 and an external circuit connection terminal 102 are provided along one side of the TFT array substrate 10 in a region located outside the sealing region in which the sealing material 52 is disposed in the peripheral region. The scanning line driving circuit 104 is provided along two sides adjacent to the one side so as to be covered with the frame light shielding film 53. Further, in order to connect the two scanning line driving circuits 104 provided on both sides of the image display region 10 a in this way, a plurality of the pixel lines are covered along the remaining side of the TFT array substrate 10 and covered with the frame light shielding film 53. Wiring 105 is provided.

  In a region facing the four corners of the counter substrate 20 on the TFT array substrate 10, vertical conduction terminals 106 for connecting the two substrates with a vertical conduction material are arranged. Thus, electrical conduction can be established between the TFT array substrate 10 and the counter substrate 20.

  In FIG. 2, on the TFT array substrate 10, a laminated structure in which pixel switching TFTs as drive elements, wiring lines such as scanning lines and data lines are formed is formed. Although the detailed configuration of this laminated structure is not shown in FIG. 2, pixel electrodes 9a made of a transparent material such as ITO (Indium Tin Oxide) are provided on the laminated structure with a predetermined pattern for each pixel. It is formed in an island shape.

  The pixel electrode 9 a is formed in the image display area 10 a on the TFT array substrate 10 so as to face the counter electrode 21. On the surface of the TFT array substrate 10 facing the liquid crystal layer 50, that is, on the pixel electrode 9a, an alignment film 16 is formed so as to cover the pixel electrode 9a.

  A light shielding film 23 is formed on the surface of the counter substrate 20 facing the TFT array substrate 10. For example, the light shielding film 23 is formed in a lattice shape when viewed in plan on the facing surface of the facing substrate 20. In the counter substrate 20, a non-opening area is defined by the light shielding film 23, and an area partitioned by the light shielding film 23 is an opening area through which light emitted from, for example, a projector lamp or a direct viewing backlight is transmitted. The light shielding film 23 may be formed in a stripe shape, and the non-opening region may be defined by the light shielding film 23 and various components such as data lines provided on the TFT array substrate 10 side.

  On the light shielding film 23, a counter electrode 21 made of a transparent material such as ITO is formed so as to face the plurality of pixel electrodes 9a. Further, in order to perform color display in the image display area 10a, a color filter (not shown in FIG. 2) may be formed on the light shielding film 23 in an area including a part of the opening area and the non-opening area. Good. An alignment film 22 is formed on the counter electrode 21 on the counter surface of the counter substrate 20.

  In addition to the above-described drive circuits such as the data line drive circuit 101 and the scanning line drive circuit 104, the image signal on the image signal line is sampled on the TFT array substrate 10 shown in FIGS. Sampling circuit that supplies lines, precharge circuit that supplies pre-charge signals of a predetermined voltage level to multiple data lines in advance of image signals, inspection of quality, defects, etc. of the electro-optical device during production or shipment An inspection circuit or the like may be formed.

  Next, an electrical configuration of the pixel portion of the electro-optical device according to the present embodiment will be described with reference to FIG. FIG. 3 is an equivalent circuit diagram of various elements, wirings, and the like in a plurality of pixels formed in a matrix forming the image display area of the electro-optical device according to this embodiment.

  In FIG. 3, a pixel electrode 9a and a TFT 30 are formed in each of a plurality of pixels formed in a matrix that forms the image display region 10a. The TFT 30 is electrically connected to the pixel electrode 9a, and performs switching control of the pixel electrode 9a during the operation of the electro-optical device according to the present embodiment. The data line 6a to which the image signal is supplied is electrically connected to the source of the TFT 30. The image signals S1, S2,..., Sn to be written to the data lines 6a may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6a. May be.

  The scanning line 11 is electrically connected to the gate of the TFT 30, and the electro-optical device according to the present embodiment pulses the scanning signals G 1, G 2,. Gm is applied in this order in a line sequential manner. The pixel electrode 9a is electrically connected to the drain of the TFT 30, and the image signal S1, S2,... Supplied from the data line 6a is closed by closing the switch of the TFT 30 serving as a switching element for a certain period. Sn is written at a predetermined timing. A predetermined level of image signals S1, S2,..., Sn written in the liquid crystal as an example of the electro-optical material via the pixel electrode 9a is held for a certain period with the counter electrode formed on the counter substrate. The

  The liquid crystal constituting the liquid crystal layer 50 (see FIG. 2) modulates light and enables gradation display by changing the orientation and order of the molecular assembly depending on the applied voltage level. For example, in the normally white mode, the transmittance for incident light is reduced according to the voltage applied in units of each pixel. In the normally black mode, the transmittance is applied in units of each pixel. As a result, the transmittance for incident light is increased, and light having a contrast corresponding to an image signal is emitted from the electro-optical device as a whole.

  In order to prevent the image signal held here from leaking, a storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode 21 (see FIG. 2). The storage capacitor 70 is a capacitive element that functions as a storage capacitor that temporarily holds the potential of each pixel electrode 9a in response to supply of an image signal. A specific configuration of the storage capacitor 70 will be described in detail later.

  Next, a specific configuration of the pixel portion that realizes the above-described operation will be described with reference to FIGS. FIG. 4 is a plan view transparently showing the arrangement of the conductive layer around the TFT of the electro-optical device according to the first embodiment. 5 is a cross-sectional view taken along the line A-A ′ of FIG. 4, and FIG. 6 is a cross-sectional view taken along the line B-B ′ of FIG. 4. In FIGS. 4 to 6, the scales of the layers and members are different from each other so that the layers and members can be recognized on the drawings. In FIG. 4, for convenience of explanation, illustration of each layer on the lower layer side from the semiconductor layer and on the upper layer side from the data line is omitted.

  4 and 5, the TFT 30 includes the semiconductor layer 1a and the gate electrode 3b.

  The semiconductor layer 1a is made of, for example, polysilicon, and has a channel region 1a ′ having a channel length along the Y direction, a data line side LDD region 1b, a pixel electrode side LDD region 1c, a data line side source / drain region 1d, and a pixel electrode side. It consists of a source / drain region 1e. That is, the TFT 30 has an LDD structure.

  The data line side source / drain region 1d and the pixel electrode side source / drain region 1e are formed substantially in mirror symmetry along the Y direction with respect to the channel region 1a '. The data line side LDD region 1b is formed between the channel region 1a 'and the data line side source / drain region 1d. The pixel electrode side LDD region 1c is formed between the channel region 1a 'and the pixel electrode side source / drain region 1e. The data line side LDD region 1b, the pixel electrode side LDD region 1c, the data line side source / drain region 1d, and the pixel electrode side source / drain region 1e are formed by implanting impurities into the semiconductor layer 1a by an impurity implantation such as an ion implantation method. This is an impurity region. The data line side LDD region 1b and the pixel electrode side LDD region 1c are formed as low concentration impurity regions with less impurities than the data line side source / drain region 1d and the pixel electrode side source / drain region 1e, respectively. According to such an impurity region, when the TFT 30 is not operating, the off-current flowing between the source region and the drain region can be reduced, and a decrease in the on-current flowing when the TFT 30 is operating can be suppressed. The TFT 30 preferably has an LDD structure. However, the TFT 30 may have an offset structure in which no impurity implantation is performed in the data line side LDD region 1b and the pixel electrode side LDD region 1c. A self-alignment type in which the data line side source / drain region and the pixel electrode side source / drain region are formed by implanting the concentration may be used.

  The gate electrode 3b is made of, for example, conductive polysilicon, and is formed so as to partially face the channel region 1a 'of the semiconductor layer 1a. The gate electrode 3b and the semiconductor layer 1a are insulated by the gate insulating film 2. A first relay layer 91 is formed in the same layer as the gate electrode 3b.

  5 and 6, the scanning line 11 is provided on the lower layer side of the TFT 30 on the TFT array substrate 10 through the base insulating film 12. The scanning line 11 includes, for example, at least one of refractory metals such as Ti (titanium), Cr (chromium), W (tungsten), Ta (tantalum), Mo (molybdenum), and Pd (palladium). It is made of a light shielding material such as a simple metal, an alloy, a metal silicide, a polysilicide, or a laminate of these. The scanning line 11 is incident on the TFT array substrate 10 from the TFT array substrate 10 side, such as back-surface reflection on the TFT array substrate 10 or light that is emitted from another liquid crystal device by a multi-plate projector or the like and penetrates the composite optical system. It also functions as a lower light-shielding film that shields the channel region 1a ′ of the TFT 30 and its periphery from the return light.

  In FIG. 6, the scanning line 11 is electrically connected to the gate electrode 3b through contact holes 82a and 82b. Thereby, the gate signal transmitted by the scanning line 11 is supplied to the gate electrode 3b.

  In addition to the function of insulating the TFT 30 from the scanning line 11 between layers, the base insulating film 12 is formed on the entire surface of the TFT array substrate 10 so that the surface of the TFT array substrate 10 is roughened when it is polished, or remains after cleaning. Thus, the pixel switching TFT 30 has a function of preventing deterioration of characteristics.

  5 and 6, a storage capacitor 70 is provided on the upper layer side of the TFT 30 on the TFT array substrate 10 with the first interlayer insulating film 41 interposed therebetween. The storage capacitor 70 is formed by arranging a lower capacitor electrode 71 and an upper capacitor electrode 72 to face each other with a dielectric film 75 therebetween. Here, the lower capacitor electrode 71 is an example of the “first capacitor electrode” of the present invention, the upper capacitor electrode 72 is an example of the “second capacitor electrode” of the present invention, and the dielectric film 75 is This is an example of the “capacitive insulating film” of the present invention.

  The upper capacitor electrode 72 is a fixed potential side capacitor electrode that is electrically connected to a constant potential source via a capacitor line 300 described later and maintained at a fixed potential. The upper capacitor electrode 72 is formed of a non-transparent metal film containing a metal or alloy such as Al (aluminum) or Ag (silver), for example, and also functions as an upper light shielding film (built-in light shielding film) that shields the TFT 30. To do. The upper capacitor electrode 72 includes, for example, at least one of refractory metals such as Ti, Cr, W, Ta, Mo, and Pd, a single metal, an alloy, a metal silicide, and a polysilicide, which are laminated. You may be comprised from things. In this case, the function of the upper capacitor electrode 72 as a built-in light shielding film can be enhanced.

  The lower capacitor electrode 71 is a pixel potential side capacitor electrode electrically connected to the pixel electrode side source / drain region 1e of the TFT 30 and the pixel electrode 9a. More specifically, the lower capacitor electrode 71 is electrically connected to the pixel electrode side source / drain region 1 e through the contact hole 83 and electrically connected to the first relay layer 91 through the contact hole 84. Has been. The first relay layer 91 is electrically connected to the second relay layer 92 through the contact hole 85. The second relay layer 92 is electrically connected to the third relay layer 93 through the contact hole 86. The third relay layer 93 is electrically connected to the pixel electrode 9 a through the contact hole 87. That is, the lower capacitor electrode 71 relays the electrical connection between the pixel electrode side source / drain region 1e and the pixel electrode 9a together with the first relay layer 91, the second relay layer 92, and the third relay layer 93. The lower capacitance electrode 71 has a function as a light absorption layer or a light shielding film disposed between the upper capacitance electrode 71 as an upper light shielding film and the TFT 30 in addition to a function as a pixel potential side capacitance electrode.

  The dielectric film 75 is, for example, a single layer structure or a multilayer structure formed of a silicon oxide (SiO 2) film such as an HTO (High Temperature Oxide) film, an LTO (Low Temperature Oxide) film, or a silicon nitride (SiN) film. have.

  The upper capacitor electrode 72, the lower capacitor electrode 71, and the dielectric film 75 described above are formed in the same region by patterning, for example, using the same mask. According to the storage capacitor 70 formed in this way, the potential holding characteristic of the pixel electrode 9a is improved, and display characteristics such as improvement of contrast and reduction of flicker can be improved.

  5 and 6, a light shielding film 200 is provided on the upper layer side of the storage capacitor 70 on the TFT array substrate 10 via the second interlayer insulating film 42. The light shielding film 200 includes, for example, tungsten silicide, and has a relatively high light shielding property among the conductive layers provided in the non-opening region.

  The light shielding film 200 is further electrically connected to the upper capacitor electrode 72 through a contact hole 250 formed in the second interlayer insulating film 42, and the potential supplied through the capacitor line 300 is applied to the upper capacitor electrode. It is configured to be able to supply. Specifically, as shown in FIG. 6, the capacitor line 300 is electrically connected to the fourth relay layer 94 through the contact hole 88. The fourth relay layer 94 is electrically connected to the light shielding film 200 through the contact hole 89. From the capacitor line 300, for example, a common counter potential (that is, a potential supplied to the counter electrode 20 (see FIG. 2)) is supplied as a fixed potential.

  In FIG. 4, the contact hole 250 that electrically connects the light shielding film 200 and the upper capacitor electrode 72 is formed so as to overlap the pixel electrode side LDD region 1 c in the TFT 30. Thus, the light shielding film 200 is disposed on the lower layer side (that is, the side closer to the TFT) in the region overlapping the pixel electrode side LDD region 1c. Therefore, the light shielding performance for the TFT can be improved. Here, in particular, since the pixel electrode side LDD region 1c is a portion where the light leakage current is relatively easily generated in the TFT 30, according to the configuration described above, it is possible to realize extremely efficient light shielding.

  5 and 6, the data line 6a, the second relay layer 92, and the fourth relay layer 94 are provided on the upper layer side of the light shielding film 200 on the TFT array substrate 10 via the third interlayer insulating film 43. ing.

  The data line 6a is electrically connected to the data line side source / drain region 1d of the semiconductor layer 1a through a contact hole 81 penetrating the first interlayer insulating film 41, the second interlayer insulating film 42, and the third interlayer insulating film 43. It is connected. The data line 6a and the inside of the contact hole 81 are made of, for example, an Al (aluminum) -containing material such as Al—Si—Cu or Al—Cu, Al alone, or a multilayer film including an Al layer and a TiN layer. The data line 6a also has a function of shielding the TFT 30 from light.

  The second relay layer 92 and the fourth relay layer 94 are formed in the same layer as the data line 6 a on the third interlayer insulating film 43. For the data line 6a, the second relay layer 92, and the fourth relay layer 94, a thin film made of a conductive material such as a metal film is formed on the third interlayer insulating film 43 by using a thin film forming method, The thin films are partially removed, i.e., patterned to be spaced apart from each other. Thus, if the data line 6a, the second relay layer 92, and the fourth relay layer 94 are formed in the same process, the manufacturing process of the device can be simplified.

  5 and 6, the capacitor line 300 and the third relay layer 93 are provided on the upper layer side of the data line 6a on the TFT array substrate 10 with the fourth interlayer insulating film 44 interposed therebetween.

  The capacitor line 300 is configured to include a metal such as aluminum, and supplies a fixed potential to the upper capacitor electrode as described above. On the other hand, the third relay layer 93 formed in the same layer as the capacitor line 300 relays electrical conduction between the pixel electrode side source / drain region 1e and the pixel electrode 9a in the semiconductor layer 1a.

  5 and 6, the pixel electrode 9 a is formed on the upper layer side of the capacitor line 300 via the fifth interlayer insulating film 45. The pixel electrode 9a is electrically connected to the pixel electrode side source / drain region 1e of the semiconductor layer 1a via the third relay layer 93, the second relay layer 92, the first relay layer, and the lower capacitor electrode 71. The contact hole 87 that electrically connects the pixel electrode 9a and the third relay layer 93 is a conductive material that constitutes the pixel electrode 9a such as ITO on the inner wall of the hole formed so as to penetrate the fifth interlayer insulating layer 45. It is formed by depositing a material. An alignment film subjected to a predetermined alignment process such as a rubbing process is provided on the upper surface of the pixel electrode 9a.

  The configuration of the pixel portion described above is common to each pixel portion, and such pixel portions are periodically formed in the image display region 10a (see FIG. 1).

  As described above, according to the electro-optical device according to the first embodiment, the storage capacitor 70 is provided, and the light shielding film 200 provides high light shielding performance for the TFT 30. Therefore, it is possible to realize an electro-optical device that can display a high-quality image with high reliability.

Second Embodiment
Next, an electro-optical device according to a second embodiment will be described with reference to FIGS. FIG. 7 is a plan view transparently showing the arrangement of the conductive layer around the TFT of the electro-optical device according to the second embodiment. 8 is a cross-sectional view taken along the line CC ′ of FIG. 7, and FIG. 9 is a cross-sectional view taken along the line DD ′ of FIG. FIG. 9 is a cross-sectional view illustrating a modification of the electro-optical device according to the second embodiment. In FIGS. 7 to 10, the scales of the layers and members are different from each other in order to make each layer and each member recognizable on the drawings. In FIG. 7, for convenience of explanation, illustration of each layer below the semiconductor layer and above the data line is omitted.

  In the second embodiment described below, a part of the laminated structure is different from the first embodiment described above, and other configurations are generally the same. Therefore, in the second embodiment, portions different from the first embodiment will be described in detail, and descriptions of other overlapping portions will be omitted as appropriate.

  7 to 9, the electro-optical device according to the second embodiment is not provided with the contact hole 250 that electrically connects the light shielding film 200 and the upper capacitor electrode 72 formed in the first embodiment. . Further, the light shielding film 200 is provided so as not to overlap the contact hole 89.

  In FIG. 9, in the electro-optical device according to the second embodiment, the contact hole 89 is electrically connected to the upper capacitor electrode 72 instead of the light shielding film 200. That is, the fixed potential supplied from the fourth relay layer 94 to the upper capacitor electrode 72 via the light shielding film 200 is directly supplied from the fourth relay layer 94 to the upper capacitor electrode 72.

  In FIG. 8, in the electro-optical device according to the second embodiment, the light-shielding film 200 is electrically connected to the second relay layer 92 through a contact hole 260 formed so as to penetrate the third interlayer insulating film 43. It is connected to the. That is, the light shielding film 200 is electrically connected to the pixel electrode side source / drain region 1e and the pixel electrode 9a in the semiconductor layer 1a. In other words, the light shielding film 200 is at the same potential as the lower capacitor electrode 71.

  According to the configuration described above, in addition to the storage capacitor 70 formed by the upper capacitor electrode 72, the lower capacitor electrode 71, and the dielectric film 75, the same applies to the upper capacitor electrode 72, the second interlayer insulating film 42, and the light shielding film 200. Storage capacity can be formed. Therefore, it is possible to realize an extremely high density storage capacity.

  In FIG. 10, the electro-optical device according to the second embodiment can be configured without providing the first relay layer 91 (see FIG. 8). That is, the lower capacitance electrode 71 may be configured to be directly electrically connected to the second relay layer 92 through the contact hole 85. In this case, since it is not necessary to provide the contact hole 84 that electrically connects the lower capacitor electrode 71 and the first relay layer 91, a high yield and a narrow pixel pitch can be realized. Note that such a configuration without the first relay layer 91 can also be applied to the above-described first embodiment.

  As described above, according to the second electro-optical device of the present invention, since a storage capacitor can be formed also in the light shielding film 200, high light shielding performance can be obtained and a high density storage capacitor can be formed. It is possible. Therefore, it is possible to realize an electro-optical device that can display a high-quality image with high reliability.

<Method of manufacturing electro-optical device>
Next, a method for manufacturing the above electro-optical device will be described with reference to FIGS. 11 to 16 are process cross-sectional views sequentially showing the manufacturing process of the electro-optical device according to the embodiment. In the following description, only the manufacturing process of each member constituting the storage capacitor 70 peculiar to the present embodiment will be described, and the description of the manufacturing process of other parts will be omitted.

  In FIG. 11, according to the method of manufacturing the electro-optical device according to the present embodiment, the lower capacitor electrode 71, the dielectric film 75, and the upper capacitor electrode 72 constituting the storage capacitor 70 are formed on the first interlayer insulating film 41. Each is stacked in order.

  In FIG. 12, the lower capacitor electrode 71, the dielectric film 75 and the upper capacitor electrode 72 are patterned by etching using the same mask 510. That is, the lower capacitor electrode 71, the dielectric film 75, and the upper capacitor electrode 72 are patterned together. As a result, the lower capacitor electrode 71, the dielectric film 75, and the upper capacitor electrode 72 are formed in the same region as viewed in plan.

  In FIG. 13, the patterned lower capacitor electrode 71, dielectric film 75, and upper capacitor electrode 72 are subjected to an oxidation treatment by applying heat, for example. According to such an oxidation treatment, an oxide film is formed on the surface of the upper capacitor electrode 72. That is, the surface of the upper capacitor electrode 72 is partially oxidized. Thereby, the pressure resistance performance of the first storage capacitor 70 can be improved.

  In FIG. 14, the second interlayer insulating film 42 is formed on the upper capacitor electrode 72. A contact hole 250 for electrically connecting the upper capacitor electrode 72 and the light shielding film 200 is formed in the second interlayer insulating film 42. The contact hole 250 is formed so as to penetrate the oxide film formed on the surface of the upper capacitor electrode 72. Therefore, according to the contact hole 250, the light shielding film 200 and the unoxidized portion of the upper capacitor electrode 72 can be electrically connected. The contact hole 250 is formed in a region overlapping the pixel electrode side LDD region 1c in the semiconductor layer 1a (see FIG. 4).

  The second interlayer insulating film 42 is formed with a thickness equal to or thinner than that of the upper capacitor electrode 72 or a light shielding film 200 described later. Therefore, the light shielding film 200 can be formed on the lower layer side (in other words, on the TFT 30 side). Therefore, the light shielding performance for the TFT 30 can be further improved.

  In FIG. 15, a light shielding film 200 is formed on the second interlayer insulating film 42. As described above, the light shielding film 200 is formed after the lower capacitor electrode 71, the dielectric film 75, and the upper capacitor electrode 72 are oxidized. That is, the light shielding film 200 is not oxidized. Here, if an oxidation treatment is performed on a high melting point metal having a high light shielding property, contamination of the processing apparatus and cracks due to stress frequently occur, which is not preferable in practice. On the other hand, if the light shielding film 200 is formed after the oxidation treatment as in the present embodiment, the above-described practical inconveniences can be avoided.

  In FIG. 16, the light shielding film 200 is patterned by etching using a mask 520. At this time, the light shielding film 200 is formed in a narrower range than the lower lower capacitive electrode 71, the dielectric film 75 and the upper capacitive electrode 72. In this way, it is possible to form the light shielding film 200 relatively easily as compared with the case where it is formed in a wider range than each member constituting the storage capacitor 70.

  As described above, according to the method of manufacturing the electro-optical device according to this embodiment, the above-described electro-optical device can be preferably manufactured. Here, the manufacturing method in the case where the upper capacitor electrode 72 and the light shielding film 200 are electrically connected (that is, the electro-optical device according to the first embodiment) has been described. If the contact hole 250 is not provided, the method can be applied as a manufacturing method when the upper capacitor electrode 72 and the light shielding film 200 are not electrically connected (that is, the electro-optical device according to the second embodiment).

<Electronic equipment>
Next, the case where the liquid crystal device which is the above-described electro-optical device is applied to various electronic devices will be described. FIG. 17 is a plan view showing a configuration example of the projector. Hereinafter, a projector using the liquid crystal device as a light valve will be described.

  As shown in FIG. 17, a projector 1100 includes a lamp unit 1102 made up of a white light source such as a halogen lamp. The projection light emitted from the lamp unit 1102 is separated into three primary colors of RGB by four mirrors 1106 and two dichroic mirrors 1108 arranged in the light guide 1104, and serves as a light valve corresponding to each primary color. The light enters the liquid crystal panels 1110R, 1110B, and 1110G.

  The configurations of the liquid crystal panels 1110R, 1110B, and 1110G are the same as those of the liquid crystal device described above, and are driven by R, G, and B primary color signals supplied from the image signal processing circuit. The light modulated by these liquid crystal panels enters the dichroic prism 1112 from three directions. In the dichroic prism 1112, R and B light is refracted at 90 degrees, while G light travels straight. Therefore, as a result of the synthesis of the images of the respective colors, a color image is projected onto the screen or the like via the projection lens 1114.

  Here, paying attention to the display images by the liquid crystal panels 1110R, 1110B, and 1110G, the display image by the liquid crystal panel 1110G needs to be horizontally reversed with respect to the display images by the liquid crystal panels 1110R and 1110B.

  Since light corresponding to the primary colors R, G, and B is incident on the liquid crystal panels 1110R, 1110B, and 1110G by the dichroic mirror 1108, it is not necessary to provide a color filter.

  In addition to the electronic devices described with reference to FIG. 17, mobile personal computers, mobile phones, liquid crystal televisions, viewfinder type, monitor direct-view type video tape recorders, car navigation devices, pagers, electronic Examples include notebooks, calculators, word processors, workstations, videophones, POS terminals, and devices with touch panels. Needless to say, the present invention can be applied to these various electronic devices.

  In addition to the liquid crystal devices described in the above embodiments, the present invention includes a reflective liquid crystal device (LCOS), a plasma display (PDP), a field emission display (FED, SED), an organic EL display, and a digital micromirror device. (DMD), electrophoresis apparatus and the like are also applicable.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification, and an electro-optical device with such a change. The electronic apparatus including the electro-optical device and the method for manufacturing the electro-optical device are also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 1a ... Semiconductor layer, 3b ... Gate electrode, 6a ... Data line, 9a ... Pixel electrode, 10 ... TFT array substrate, 10a ... Image display area, 11 ... Scanning line, 20 ... Counter substrate, 30 ... TFT, 50 ... Liquid crystal layer , 70: Storage capacitor, 71: Lower capacitor electrode, 72: Upper capacitor electrode, 75 ... Dielectric film, 200 ... Light shielding film, 300 ... Capacitor line.

Claims (5)

A pixel electrode;
A semiconductor layer disposed between a substrate and the pixel electrode;
A gate electrode disposed opposite to the semiconductor layer via a gate insulating film;
A first capacitor electrode electrically connected to the pixel electrode and the semiconductor layer;
A second capacitor electrode disposed between the pixel electrode and the first capacitor electrode so as to be opposed to the first capacitor electrode via a first capacitor insulating film;
A light-shielding film disposed between the pixel electrode and the second capacitor electrode so as to be opposed to the second capacitor electrode via a second capacitor insulating film and forming a second storage capacitor;
The first capacitor electrode is electrically connected to the light shielding film,
The electro-optical device is characterized in that the light shielding film overlaps at least a part of the semiconductor layer in a plan view and is provided in a region inside the region in which the second capacitor electrode is provided in a plan view. . The semiconductor layer has a channel region overlapping with the gate electrode and a plurality of LDD regions sandwiching the channel region,
2. The electro-optical device according to claim 1 , wherein the second capacitor electrode and the light shielding film at least partially overlap an LDD region that is electrically located on the pixel electrode side among the plurality of LDD regions. . The second capacitor electrode, electro-optical device according to claim 1 or 2, characterized in that opposite the common potential supplied to the counter electrode disposed to face each other through the pixel electrode and the electro-optical material is applied . The first capacitor electrode via the relay layer provided on the gate electrode and the same layer, in any one of claims 1 to 3, characterized in that the are the pixel electrode electrically connected The electro-optical device described. An electronic device characterized by being provided with the electro-optical device according to claim 1, any one of four.

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