JP2010204600A - Electrooptical device and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simultaneously attain reduction in the cost required for manufacturing of an electrooptical device, like a liquid crystal and improvement of display performance. <P>SOLUTION: A TFT (30) includes a semiconductor layer (30a), formed in the same layer as lower side capacity electrodes (80a) and (80b) on a TFT array substrate (10); a gate insulating film (30b) formed over the semiconductor layer; and a gate electrode (30c). The semiconductor layer (30a) is formed, such that its width along the substrate surface of the TFT array substrate (10) is larger than the thickness along the thickness direction of the TFT array substrate (10). Consequently, according to the TFT (30) and holding capacity (70), the TFT (30) can be formed by a step common to the lower side capacity electrodes (80a) and (80b), including a semiconductor, such as, polysilicon, when manufacturing a liquid crystal (1); and thus the manufacturing process of the liquid crystal device (1) can be simplified, and the manufacturing cost can be reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technical field of, for example, an electro-optical device including a capacitor element and a transistor element that are configured using a common semiconductor layer, and a manufacturing method thereof.

  In a manufacturing method of a liquid crystal device which is an example of this type of electro-optical device, a capacitive element for holding a potential of a pixel electrode while increasing an aperture ratio of a plurality of pixels constituting an image display region on a substrate, By using the stepped portion formed on the substrate and increasing the size of the capacitive element in three dimensions compared to the case of forming the capacitive element in a plane, a larger capacitance value in a certain region. A technology capable of forming a capacitive element having a thickness is disclosed (for example, see Patent Document 1).

  In this type of liquid crystal device, a component such as a semiconductor element that constitutes a part of a drive circuit provided around the image display region or a pixel switching element provided for each pixel is a pixel. It is formed in a separate process from the constituent elements of the capacitive element provided for each.

JP-A-2005-115104

  However, there has been a continuing demand for reduction in costs required for manufacturing electro-optical devices such as liquid crystal devices. In addition, there is a request for improving display performance in parallel with cost reduction. More specifically, for example, there is a request for increasing the capacitance value of a capacitor element such as a storage capacitor provided to hold a potential of a pixel electrode set according to an image signal for a certain period.

  Therefore, the present invention has been made in view of the above-described problems, for example, an electro-optical device in which cost reduction required for manufacturing an electro-optical device such as a liquid crystal device and an improvement in display performance are realized at the same time, and It is an object to provide a manufacturing method thereof.

  In order to solve the above problems, an electro-optical device according to the present invention has a plurality of pixels arranged in a pixel region on a substrate, a transistor element provided for each pixel, and the same semiconductor layer as the transistor element. A capacitor element having a first capacitor electrode formed simultaneously from the semiconductor film and a second capacitor electrode disposed opposite to the first capacitor electrode, wherein the first capacitor electrode has a thickness greater than that of the semiconductor layer; Is formed large.

  According to the electro-optical device according to the invention, the plurality of pixel electrodes are made of a transparent conductive material such as ITO, for example, and are provided in a matrix in the display area.

  The capacitive element is electrically connected to the pixel electrode. For example, in an electro-optical device such as a liquid crystal device, the capacitive element is a storage capacitor that holds the potential of the pixel electrode at a potential corresponding to an image signal for a certain period. is there. The capacitor element includes a first capacitor electrode formed simultaneously from the same semiconductor film as the semiconductor layer of the transistor element, and a second capacitor electrode disposed opposite to the first capacitor electrode.

  Therefore, according to the electro-optical device according to the present invention, the capacitive element is formed on the substrate so as to have a larger capacitance value within a narrow region in plan view. In some cases, the holding performance of holding the potential of the pixel electrode for a certain period according to the image signal can be improved, and the display performance of the electro-optical device displaying an image can be improved.

  The transistor element has an active layer formed in the same layer as the first capacitor electrode on the substrate. Therefore, according to the electro-optical device according to the present invention, for example, when the electro-optical device is manufactured, the transistor element can be formed by a process common to the first capacitor electrode made of a semiconductor such as polysilicon. The manufacturing process can be simplified and the manufacturing cost can be reduced.

  Therefore, according to the electro-optical device according to the present invention, the capacitive element is formed on the substrate so as to have a larger capacitance value within a narrow region in plan view. With respect to the electro-optical device, it is possible to improve display performance without expanding a non-opening region which is configured by an opaque portion such as a capacitor element of a pixel and substantially does not transmit light. In addition, since the transistor element and the capacitor can be formed by a common manufacturing process, the manufacturing cost of the electro-optical device can be reduced.

  In one aspect of the electro-optical device according to the invention, the capacitive element may be formed in a frame shape so as to surround a pixel electrode provided corresponding to the pixel in a plan view.

  According to this aspect, in an electro-optical device such as a liquid crystal device, it is possible to increase the capacitance value of the capacitive element without narrowing the aperture region through which light can substantially transmit.

  In another aspect of the electro-optical device according to the invention, the second capacitor electrode may be formed across the plurality of pixels.

  According to this aspect, the manufacturing process can be simplified as compared with the case where the second capacitor electrode is individually formed for each of the plurality of capacitor elements.

  In another aspect of the electro-optical device according to the invention, the first capacitor electrode is a plurality of first sub-capacitance electrodes electrically connected to each other, and the first capacitor electrode, the second capacitor electrode, The capacitor insulating film formed between the plurality of sub-capacitor insulating films is formed on the plurality of first sub-capacitor electrodes, and the second capacitor electrode includes the plurality of sub-capacitor insulating films. It may be formed on a film.

  According to this aspect, the capacitance value of the capacitive element can be further increased.

  In another aspect of the electro-optical device according to the invention, the first capacitor electrode includes a second sub-capacitance electrode extending along a thickness direction, and extending along a substrate surface of the substrate, and the second sub-capacitance electrode. A third sub-capacitance electrode electrically connected to the capacitor, and the capacitor insulating film is formed to cover the surfaces of the second sub-capacitance electrode and the third sub-capacitance electrode, respectively. Also good.

  According to this aspect, the capacitance value of the capacitive element can be further increased.

  In another aspect of the electro-optical device according to the invention, the transistor element may be a pixel switching element electrically connected to the pixel electrode.

  According to this aspect, the pixel switching element and the capacitive element can be formed in a common process. In addition, since the light is shielded by the capacitive element, the optical rook current generated in the pixel switching element can be reduced.

  In another aspect of the electro-optical device according to the present invention, the electro-optical device includes a second transistor element that constitutes a part of a circuit portion provided around the pixel region, and the semiconductor layer of the second transistor is the first semiconductor. The film thickness may be larger than that of the layer, and the film thickness may be substantially the same as that of the first capacitor electrode.

  According to this aspect, for example, a part of the circuit unit such as the data line driving circuit and the investigation line driving circuit can be formed by a process common to the capacitive element.

  In another aspect of the electro-optical device according to the invention, the semiconductor layer of the pixel switching element is formed such that a width along the substrate surface of the substrate is larger than a thickness along the thickness direction, It may be a planar transistor element having a channel region extending in a plane along the substrate surface of the substrate.

  According to this aspect, a transistor element can be formed as a planar transistor element.

  In another aspect of the electro-optical device according to the invention, the semiconductor layer of the second transistor element is formed so that a width along the substrate surface of the substrate is smaller than a thickness along the thickness direction, A fin type transistor element having a channel width along the substrate surface of the substrate may be used.

  According to this aspect, a transistor element can be formed as a fin-type transistor element.

  In order to solve the above problems, a method for manufacturing an electro-optical device according to the present invention includes a first step of forming a stepped portion in one region on a substrate, an upper surface and a side surface of the stepped portion, and another step on the substrate. A second step of forming a semiconductor film continuously extending over the region; and forming a first capacitor electrode of a capacitive element covering the upper surface and side surface of the step from the semiconductor film, and simultaneously from the semiconductor film to the other region A third step of forming a semiconductor layer of the transistor element; a fourth step of forming a gate insulating film on the semiconductor layer simultaneously with forming a capacitive insulating film on the first semiconductor layer; and And a fifth step of forming a gate electrode on the gate insulating film simultaneously with forming the second capacitor electrode.

  According to the electro-optical device according to the present invention, the electro-optical device according to the above-described invention can be manufactured by a simple process.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

It is a top view of the liquid crystal device concerning this embodiment. It is II-II 'sectional drawing of FIG. FIG. 4 is a circuit diagram illustrating a circuit configuration in an image display region of the liquid crystal device according to the present embodiment. 4 is a plan view schematically showing an arrangement state of a plurality of pixels constituting an image display region of the liquid crystal device according to the embodiment. FIG. It is the top view which showed the specific structure in a part of liquid crystal device which concerns on this embodiment. It is VI-VI 'sectional drawing of FIG. It is the plane process drawing (the 1) which showed the main process of the manufacturing method of the liquid crystal device concerning this embodiment in order. It is the plane process drawing (the 2) which showed the main process of the manufacturing method of the liquid crystal device concerning this embodiment in order. It is sectional process drawing (the 1) which showed the main process of the manufacturing method of the liquid crystal device concerning this embodiment in order. It is sectional process drawing (the 2) which showed the main process of the manufacturing method of the liquid crystal device which concerns on this embodiment in order. It is the top view which showed a part of specific structure of the modification (modification 1) of the liquid crystal device which concerns on this embodiment. It is XII-XII 'sectional drawing of FIG. It is the plane process drawing (the 1) which showed the main process of the modification (modification 1) of the manufacturing method of the liquid crystal device concerning this embodiment in order. It is the plane process drawing (the 2) which showed the main process of the modification (modification 1) of the manufacturing method of the liquid crystal device concerning this embodiment in order. It is sectional process drawing (the 1) which showed the main process of the modification (modification 1) of the manufacturing method of the liquid crystal device which concerns on this embodiment in order. It is sectional process drawing (the 2) which showed the main process of the modification (modification 1) of the manufacturing method of the liquid crystal device which concerns on this embodiment in order. It is the top view which showed the specific structure of the other modification (modification 2) of the liquid crystal device which concerns on this embodiment. It is XVIII-XVIII 'sectional drawing of FIG. It is the top view which showed the specific structure of the other modification (modification 3) of the liquid crystal device which concerns on this embodiment. It is XX-XX 'sectional drawing of FIG. It is sectional drawing which concerns on the modification of the structure shown in FIG. It is XXII-XXII 'sectional drawing of FIG. FIG. 23 is a cross-sectional view according to a modified example of the structure shown in FIG. 22. It is the top view which showed the specific structure of the other modification (modification 4) of the liquid crystal device which concerns on this embodiment. It is the top view which showed the specific structure of the other modification (modification 5) of the liquid crystal device which concerns on this embodiment. It is the top view which showed the specific structure of the other modification (modification 6) of the liquid crystal device which concerns on this embodiment. It is the top view which showed the specific structure of the other modification (modification 7) of the liquid crystal device which concerns on this embodiment.

  Hereinafter, a liquid crystal device which is an embodiment of an electro-optical device according to the invention and a manufacturing method thereof will be described with reference to the drawings.

<1: Liquid crystal device>
<1-1: Overall Configuration of Liquid Crystal Device>
First, the overall configuration of the liquid crystal device 1 according to the present embodiment will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a plan view showing the overall configuration of the liquid crystal device 1 according to the present embodiment, and FIG. 2 is a cross-sectional view taken along the line II-II ′ of FIG.

  1 and 2, the liquid crystal device 1 includes a TFT array substrate 10 and a counter substrate 20 that are arranged to face each other. The TFT array substrate 10 is an example of the “substrate” in the present invention. The TFT array substrate 10 is, for example, a transparent substrate such as a quartz substrate or a glass substrate, or a silicon substrate. The counter substrate 20 is a substrate made of the same material as the TFT array substrate 10, for example. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20, and the TFT array substrate 10 and the counter substrate 20 are sealed around the image display region 10a where the electro-optical operation is performed. They are bonded to each other by a sealing material 52 provided in the region. The image display area 10a is an example of the “pixel area” in the present invention.

  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. Further, for example, in the sealing material 52, a gap material 56 such as a glass fiber or a glass bead for dispersing the distance (inter-substrate gap) between the TFT array substrate 10 and the counter substrate 20 to a predetermined value is dispersed.

  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. However, 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, a sampling circuit 7, a scanning line driving circuit 104, and an external circuit connection terminal 102 are formed in the peripheral area located around the image display area 10 a on the TFT array substrate 10. The data line driving circuit 101, the sampling circuit 7, and the scanning line driving circuit 104 constitute an example of the “circuit portion” in the present invention.

  In the peripheral region on the TFT array substrate 10, a data line driving circuit 101 and a plurality of external circuit connection terminals 102 are provided along one side of the TFT array substrate 10 on the outer peripheral side of the seal region.

  In the peripheral region on the TFT array substrate 10, the region located inside the seal region is sampled along one side of the image display region 10 a along one side of the TFT array substrate 10 and covered with the frame light shielding film 53. A circuit 7 is arranged.

  The scanning line driving circuit 104 is provided along two sides adjacent to one side of the TFT array substrate 10 so as to be covered with the frame light shielding film 53. Further, in order to electrically connect the two scanning line driving circuits 104 provided on both sides of the image display region 10a in this way, the TFT array substrate 10 is covered with the frame light shielding film 53 along the remaining side. A plurality of wirings 105 are provided.

  In the peripheral region on the TFT array substrate 10, vertical conduction terminals 106 are disposed in regions facing the four corners of the counter substrate 20, and vertical conduction is provided between the TFT array substrate 10 and the counter substrate 20. A material is provided corresponding to the vertical conduction terminal 106 and electrically connected to the terminal 106.

  In FIG. 2, on the TFT array substrate 10, a laminated structure is formed in which wirings such as TFTs for pixel switching, scanning lines, and data lines are formed. In the image display area 10a, pixel electrodes 9 are provided in a matrix form on the upper layer of wiring such as pixel switching TFTs, scanning lines, and data lines. The pixel electrode 9 is formed as a transparent electrode made of an ITO film. An alignment film 16 is formed on the pixel electrode 9.

  On the other hand, a light shielding film 23 is formed on the surface of the counter substrate 20 facing the TFT array substrate 10. The light shielding film 23 is formed of, for example, a light shielding metal film or the like, and is patterned, for example, in a lattice shape in the image display region 10a on the counter substrate 20. On the light shielding film 23 (below the light shielding film 23 in FIG. 2), the counter electrode 21 made of an ITO film is formed, for example, in a solid shape so as to face the plurality of pixel electrodes 9, and further on the counter electrode 21 (FIG. 2, below the counter electrode 21), an alignment film 22 is formed.

  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 the pair of alignment films. When the liquid crystal device is driven, a voltage is applied to each of them, so that a storage capacitor is formed between the pixel electrode 9 and the counter electrode 21.

<1-2: Electrical configuration of liquid crystal device>
Next, the electrical configuration of the image display area 10a of the liquid crystal device 1 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 that forms the image display region 10a of the liquid crystal device 1 according to the present embodiment.

  In FIG. 3, a pixel electrode 9 and a TFT 30 which is an example of the “transistor element” of the present invention are formed in each of a plurality of pixels formed in a matrix forming the image display region 10 a. The TFT 30 is electrically connected to the pixel electrode 9, and performs switching control of the pixel electrode 9 so as to switch between supply and non-supply of the image signal to the pixel electrode 9 during operation of the liquid crystal device 1. The data line 6 to which the image signal is supplied is electrically connected to the source region of the TFT 30. Image signals S1, S2,..., Sn to be written to the data lines 6 may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6. Good.

  The scanning line 11 is electrically connected to the gate of the TFT 30, and the liquid crystal device 1 sequentially applies the scanning signals G 1, G 2,..., Gm to the scanning line 11 in this order at a predetermined timing. It is comprised so that it may apply. The pixel electrode 9 is electrically connected to the drain of the TFT 30. By closing the switch of the TFT 30 serving as a pixel switching element for a certain period, the image signals S1, S2,. Sn is written at a predetermined timing. A predetermined level of image signals S1, S2,..., Sn written to the liquid crystal via the pixel electrode 9 is constant between the counter electrode 21 (see FIG. 2) formed on the counter substrate 20 (see FIG. 2). Hold for a period.

  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. In the normally white mode, the transmittance for incident light is reduced according to the voltage applied in units of each pixel, and in the normally black mode, the light is incident according to the voltage applied in units of each pixel. The transmittance for light is increased, and light having a contrast corresponding to an image signal is emitted from the liquid crystal 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 9 and the counter electrode 21 (see FIG. 2). ing. The storage capacitor 70 is an example of the “capacitance element” in the present invention.

<1-3: Arrangement State of Pixels Constructing Image Display Area>
Next, the arrangement state of the pixels 90g constituting the image display area 10a will be described with reference to FIG. FIG. 4 is a plan view schematically showing an arrangement state of a plurality of pixels 90 g constituting the image display area 10 a of the liquid crystal device 1.

  As shown in FIG. 4, the plurality of pixels 90g are arranged in a matrix along the X direction and the Y direction in the figure on the TFT array substrate 10, and constitute an image display region 10a. Each of the plurality of pixel electrodes 9 (see FIG. 2) is formed on each of the plurality of pixels 90g. The area outside the image display area 10a of the TFT array substrate 10 is a peripheral area 190a that does not contribute to image display.

<1-4: Specific Configuration of Liquid Crystal Device>
Next, a specific configuration of the liquid crystal device 1 will be described with reference to FIGS. 5 and 6. FIG. 5 is a plan view showing a specific configuration of a part of the liquid crystal device 1 according to the present embodiment, and FIG. 6 is a sectional view taken along the line VI-VI ′ of FIG. In FIGS. 5 and 6, a region 90g-1 that constitutes a part of the pixel 90g and a region 190a-1 that constitutes a part of the peripheral region 190a are shown side by side.

  As shown in FIGS. 5 and 6, the liquid crystal device 1 includes a storage capacitor 70 and TFTs 30 and 130.

  Each of the storage capacitors 70 constitutes one example of the “first capacitor electrode” of the present invention, and the lower capacitor electrodes 80a and 80b, which are examples of the “plurality of first sub-capacitor electrodes” of the present invention, Each of them constitutes one example of the “capacitor insulating film” of the present invention, and capacitive insulating films 81a and 81b, which are examples of the “plurality of sub-capacitor insulating films” of the present invention, and the “second capacitor electrode” of the present invention. ”And upper capacitor electrodes 82a and 82b that constitute an example.

  The lower capacitive electrodes 80a and 80b are formed by patterning simultaneously from the semiconductor layer 30a and the same semiconductor film such as polysilicon constituting the semiconductor layers 140a and 140b, and on the base film 40, the semiconductor layer 30a is formed. The semiconductor layers 140a and 140b are formed in the same layer. In addition, the lower capacitor electrodes 80 a and 80 b are electrically connected to each other and extend along the thickness direction of the TFT array substrate 10. Since the lower capacitive electrodes 80a and 80b extend along the thickness direction of the TFT array substrate 10, compared to the case where the lower capacitive electrodes are formed to extend along the substrate surface of the TFT array substrate 10. It has a large surface area in a narrow region in plan view. The planar widths of the lower capacitor electrodes 80a and 80b and the semiconductor layers 140a and 140b are formed to be substantially the same, and are formed to be substantially the same as the film thickness of the semiconductor layer 30a or thinner than the film thickness of the semiconductor layer 30a. Is done.

  The capacitor insulating films 81a and 81b are formed on the lower capacitor electrodes 80a and 80b, respectively. Each of the capacitive insulating films 81a and 81b is formed by newly forming an insulating film on the respective surfaces of the lower capacitive electrodes 80a and 80b, or by oxidizing the respective surfaces of the lower capacitive electrodes 80a and 80b. Is formed. That is, the capacitive insulating films 81a and 81b are formed by patterning simultaneously from the same insulating film as the gate insulating film 30b and the gate insulating films 141a and 141b, respectively. Accordingly, each of the capacitive insulating films 81a and 81b is configured to have a wide area in a narrow region as viewed in a plane, similarly to the lower capacitive electrodes 80a and 80b.

  The upper capacitive electrodes 82a and 82b constitute one capacitive electrode 82 formed on the capacitive insulating films 81a and 81b, and constitute a pair of capacitive electrodes together with the lower capacitive electrodes 80a and 80b. That is, the upper capacitor electrodes 82a and 82b are formed by simultaneously patterning the same conductive film as the gate electrode 30c and the gate electrodes 142a and 142b, respectively. Note that one of the upper capacitor electrodes 82a and 82b is electrically connected to the drain of the TFT 30, and the other is electrically connected to a wiring to which a fixed potential or a common potential is supplied.

  Therefore, according to the liquid crystal device 1, the storage capacitor 70 is formed on the TFT array substrate 10 so as to have a larger capacitance value within a narrow region in plan view. At times, the holding performance of holding the potential of the pixel electrode 9 for a certain period according to the image signal can be improved, and the display performance of the liquid crystal device 1 for displaying an image can be improved. In addition, according to the storage capacitor 70, since the storage capacitor 70 is a so-called fin-type capacitor element, compared to a storage capacitor composed of a capacitor electrode and a capacitor insulating film that extend along the substrate surface of the TFT array substrate 10. It is possible to secure a larger capacity value within a certain area and further improve the display performance of the liquid crystal device 1 for displaying an image.

  Further, according to the storage capacitor 70 which is a so-called fin-type capacitor element, light irradiated to the TFT 30 disposed in the vicinity thereof can be shielded, so that a light leakage current generated in the TFT 30 can be reduced.

  The TFT 30 includes a semiconductor layer 30a formed in the same layer as the lower capacitor electrodes 80a and 80b on the TFT array substrate 10, a gate insulating film 30b formed thereon, and a gate electrode 30c. Yes. The semiconductor layer 30 a is formed so that the width in the direction along the substrate surface of the TFT array substrate 10 is larger than the thickness along the thickness direction of the TFT array substrate 10. The TFT 30 is a planar thin film transistor having a channel region that extends in a plane along the substrate surface of the TFT array substrate 10.

  Therefore, according to the TFT 30 and the storage capacitor 70, the TFT 30 can be formed by patterning simultaneously with the lower capacitor electrodes 80a and 80b made of a semiconductor film such as polysilicon when the liquid crystal device 1 is manufactured. The manufacturing process of the apparatus 1 can be simplified and the manufacturing cost can be reduced.

  Therefore, according to the liquid crystal device 1, the storage capacitor 70 is formed on the TFT array substrate 10 so as to have a larger capacitance value within a narrow region in plan view. The display performance of the liquid crystal device 1 can be improved without expanding a non-opening region that is configured by an opaque portion such as the capacitor 70 and substantially does not transmit light. In addition, since the TFT 30 and the storage capacitor 70 can be formed by a common manufacturing process, the manufacturing cost of the liquid crystal device 1 can be reduced.

  In the present embodiment, the TFT 130 may be an example of the “transistor element” of the present invention. The TFT 130 is an element that constitutes a part of a circuit unit such as a data line driving circuit provided in the peripheral region 190 a-1 on the TFT array substrate 10.

  The TFT 130 includes semiconductor layers 140a and 140b formed such that the width in the direction along the substrate surface of the TFT array substrate 10 is smaller than the thickness along the thickness direction of the TFT array substrate 10; The gate insulating films 141a and 141b are formed on the gate insulating film, and the gate electrodes 142a and 142b are formed on the gate insulating films. The TFT 130 is a fin-type transistor element having a channel width along the substrate surface of the TFT array substrate 10, and the semiconductor layers 140 a and 140 b are formed when the lower capacitor electrodes 80 a and 80 b are formed on the TFT array substrate 10. In parallel with the formation of these lower capacitive electrodes, they are formed in the same layer as the lower capacitive electrodes 80a and 80b.

  According to the TFT 130, a part of circuit portions such as the data line driving circuit 101 and the scanning line driving circuit 104 and the storage capacitor 70 can be formed by a common process. In addition, according to the TFT 130, the manufacturing process of the liquid crystal device 1 can be simplified and the manufacturing cost can be reduced similarly to the TFT 30.

<1-5: Manufacturing method of liquid crystal device>
Next, a method for manufacturing the liquid crystal device 1 will be described with reference to FIGS. 7 and 8 are plan process diagrams sequentially showing main processes of the method for manufacturing the liquid crystal device 1. FIG. 9 and 10 are cross-sectional process diagrams sequentially showing main processes of the method for manufacturing the liquid crystal device 1. FIG.

  As shown in FIGS. 7A and 9A, stepped portions 61 and 62 made of an insulating film such as silicon oxide are formed in the regions 90g-1 and 190a-1 on the base film 40, respectively. . Next, as shown in FIGS. 7B and 9B, the surface of each of the step portions 61 and 62 extends from the surface of the base film 40 to the region where the step portions 61 and 62 are not formed. A continuously extending semiconductor film 80s is formed.

  Next, as shown in FIGS. 7C and 9C, resist films 90, 91, and 92 are formed. Next, as shown in FIGS. 7D and 9D, the semiconductor film 80 s is etched from above the resist films 90, 91, and 92. By the etching process, the upper and side surfaces of the stepped portions 61 and 62 and the region where the stepped portion 61 is not formed in the region 90g-1, respectively, from the semiconductor film 80s to the lower capacitive electrodes 80a and 80b, and the semiconductor Layers 140a and 140b and semiconductor layer 30a are formed. The planar widths of the lower capacitor electrodes 80a and 80b and the semiconductor layers 140a and 140b are formed to be substantially the same as the film thickness of the semiconductor layer 30a or slightly thinner than the film thickness of the semiconductor layer 30a by etching treatment.

  Next, as shown in FIGS. 8E and 10E, capacitive insulating films 81a and 81b are formed on the surfaces of the lower capacitive electrodes 80a and 80b, and gate insulation is formed on the surfaces of the semiconductor layers 140a and 140b. Films 141a and 141b are formed. At the same time, a gate insulating film 30b is formed on the semiconductor layer 30a.

  Next, as shown in FIGS. 8F and 10F, a conductive film 82s is formed on the surfaces of the capacitor insulating films 81a and 81b, the gate insulating film 30b, and the gate insulating films 141a and 141b. . Next, as shown in FIGS. 8G and 10G, the upper capacitive electrodes 82a and 82b, the gate electrode 30c, and the gate electrodes 142a and 142b are formed and held by patterning the conductive film 82s. A capacitor 70 and TFTs 30 and 130 are formed. After that, among the components of the liquid crystal device 1, the components formed on the storage capacitor 70 and the TFTs 30 and 130 are sequentially formed to complete the liquid crystal device 1.

  According to such a manufacturing method of the liquid crystal device 1, the above-described liquid crystal device 1 can be easily formed. In addition, the storage capacitor 70 and the TFTs 30 and 130 can be formed in parallel.

  Hereinafter, a modification of the liquid crystal device 1 according to the present embodiment and the manufacturing method thereof will be described. It should be noted that portions common to those of the liquid crystal device 1 and the manufacturing method thereof are denoted by common reference numerals, and detailed description thereof is omitted.

<2: Modification>
(Modification 1)
The configuration of the liquid crystal device according to this example will be described with reference to FIGS. FIG. 11 is a plan view showing a specific configuration of a part of the liquid crystal device according to this example. 12 is a cross-sectional view taken along the line XII-XII ′ of FIG.

  As shown in FIGS. 11 and 12, the liquid crystal device according to this example is different from the above-described liquid crystal device 1 in that a holding capacitor 170 is provided instead of the holding capacitor 70.

  The storage capacitor 170 includes a lower capacitor electrode 180, a capacitor insulating film 181, and an upper capacitor electrode 182 that are formed so as to cover the stepped portion 63 formed on the base film 40.

  The lower capacitor electrode 180 includes a sub capacitor electrode 180a extending along the thickness direction of the TFT array substrate 10 and the same film extending along the substrate surface of the TFT array substrate 10 and electrically connected to the sub capacitor electrode 180a. And a sub-capacitance electrode 180b. Each of the sub-capacitance electrodes 180a and 180b. 2 is an example of each of a “second sub-capacitance electrode” and a “third sub-capacitance electrode” of the present invention. The capacitive insulating film 181 is formed on the surface of the lower capacitive electrode 180, and the upper capacitive electrode 182 is formed on the surface of the capacitive insulating film 181. Similar to the storage capacitor 70, the storage capacitor 170 can have a larger capacitance value, and the same effect as that obtained by the liquid crystal device 1 can be obtained.

  Next, a manufacturing method of the liquid crystal device according to this example will be described with reference to FIGS. 13 and 14 are plan process diagrams sequentially illustrating main processes of the method for manufacturing the liquid crystal device according to this example. 15 and 16 are cross-sectional process diagrams sequentially illustrating main processes of the manufacturing method of the liquid crystal device according to this example.

  As shown in FIGS. 13A and 15A, a stepped portion 63 is formed on the base film 40 in the region 90g-1. Next, as shown in FIGS. 13B and 15B, a semiconductor layer 180s extending continuously to the region 90g-1 so as to cover the upper surface and side surfaces of the stepped portion 63 is formed.

  Next, as shown in FIGS. 13C and 15C, resist films 190 and 191 are formed. Next, as shown in FIGS. 13D and 15D, the semiconductor film 80s is etched from above the resist films 190 and 191, and the semiconductor layer 30a and the lower capacitive electrode patterned by the etching process are etched. 180 is formed.

  Next, as shown in FIGS. 14E and 16E, the gate insulating film 30b and the capacitor insulating film 181 are formed so as to cover the surfaces of the semiconductor layer 30a and the lower capacitor electrode 180, respectively. Next, as illustrated in FIGS. 14F and 16F, a conductive film 182s is formed so as to cover the surfaces of the gate insulating film 30b and the capacitor insulating film 181.

  Next, as shown in FIGS. 14G and 16G, the upper capacitor electrode 182 is patterned by patterning the conductive film 82s formed on the respective surfaces of the capacitor insulating film 181 and the gate insulating film 30b. Then, the gate electrode 30c is formed, and the storage capacitor 170 and the TFT 30 are formed. After that, among the components of the liquid crystal device according to this example, the components formed on the storage capacitor 170 and the TFT 30 are sequentially formed to complete the liquid crystal device.

  According to such a method for manufacturing a liquid crystal device, the above-described liquid crystal device according to this example can be easily formed. In addition, the storage capacitor 170 and the TFT 30 can be formed in parallel.

(Modification 2)
Next, the configuration of Modification Example 2 of the liquid crystal device according to the present embodiment will be described with reference to FIGS. 17 and 18. FIG. 17 is a plan view showing a specific configuration of the liquid crystal device according to this example. 18 is a cross-sectional view taken along the line XVIII-XVIII ′ of FIG. In the following modifications, the configuration of four pixels adjacent to each other among the plurality of pixels configuring the image display region 10a will be described in detail. In each of the cross-sectional views shown below, for convenience of explanation, the components formed on the upper layer side of the storage capacitor are omitted from the components of the liquid crystal device.

  As shown in FIGS. 17 and 18, the liquid crystal device according to this example includes a pixel electrode 9 formed in each pixel, a TFT 230 that is a pixel switching element provided between the pixel electrodes 9 adjacent to each other, The storage capacitor 270, the scanning line 11 extending in the X direction in FIG. 17, and the data line 3 extending in the Y direction in FIG. 17 are provided.

  The TFT 230 is a fin-type thin film transistor, and includes semiconductor layers 240a and 240b, gate insulating films 241a and 241b, and gate electrodes 242a and 242b. The gate electrodes 242a and 242b constitute a gate electrode 242 made of one conductive film. The TFT 230 has its gate electrode electrically connected to the scanning line 3 via a relay layer formed in the upper layer or the lower layer, and is switching-controlled by a scanning signal. The TFT 230 is electrically connected to the data line 6 and the pixel electrode 9 and supplies an image signal supplied via the data line 6 to the pixel electrode 9.

  The storage capacitor 270 includes a lower capacitor electrode 280, a capacitor insulating film 281, and an upper capacitor electrode 282. The storage capacitor 270 is formed in a frame shape so as to surround the pixel electrode 9 in plan view. Therefore, the storage capacitor 270 can increase the capacitance value of the storage capacitor 270 in the liquid crystal device according to this example without narrowing an opening region through which light can be substantially transmitted.

  The storage capacitor 270 is a fin-type capacitor element in which each of the lower capacitor electrode 280, the capacitor insulating film 281 and the upper capacitor electrode 282 extends in the thickness direction of the TFT array substrate 10, and is a semiconductor layer such as polysilicon. A certain lower capacitance electrode 280 and semiconductor layers 240a and 240b are formed on the TFT array substrate 10 in parallel with the same layer. Therefore, according to the liquid crystal device according to this example, since the storage capacitor 270 and the TFT 230 are formed through a common process, the manufacturing process of the liquid crystal device can be simplified.

  In addition, according to the liquid crystal device of this example, the upper capacitor electrodes 282 of the storage capacitors 270 adjacent to each other along the Y direction in FIG. Is formed. Therefore, the liquid crystal device according to this example has an advantage that the manufacturing process of the liquid crystal device can be simplified as compared to the case where the upper capacitor electrode 282 is individually formed for each of the plurality of storage capacitors 270.

(Modification 3)
Next, the configuration of Modification Example 3 of the liquid crystal device according to the present embodiment will be described with reference to FIGS. FIG. 19 is a plan view showing a specific configuration of the liquid crystal device according to this example. 20 is a cross-sectional view taken along the line XX-XX ′ of FIG. FIG. 21 is a cross-sectional view according to a modification of the cross-sectional structure shown in FIG. 22 is a cross-sectional view taken along the line XXII-XXII ′ in FIG. FIG. 23 is a cross-sectional view according to a modification of the cross-sectional structure shown in FIG.

  As shown in FIGS. 19 and 20, the liquid crystal device according to this example includes a pixel electrode 9 formed in each pixel, and a TFT 330A which is a pixel switching element provided between the pixel electrodes 9 adjacent to each other. The storage capacitor 270A, the scanning line 11 extending in the X direction in FIG. 19, and the data line 6 extending in the Y direction in FIG. 19 are provided.

  The TFT 330A is a planar thin film transistor provided as a pixel switching element, and includes a semiconductor layer 330a, a gate insulating film 330b, and a gate electrode 330c formed on the gate insulating film 330b.

  The storage capacitor 270 </ b> A is formed so as to overlap the edge of the step portion 264 formed on the base film 40. The storage capacitor 270A includes a lower capacitor electrode 270a, a capacitor insulating film 270b, and an upper capacitor electrode 270c. The lower capacitor electrode 270a is formed on a side surface constituting a part of the surface of the step portion 264. The storage capacitor 270A is formed in a frame shape so as to surround the pixel electrode 9 when seen in a plan view. Therefore, the storage capacitor 270A can increase the capacitance value of the storage capacitor 270A without narrowing the aperture region through which light can be substantially transmitted in the pixel in the liquid crystal device according to this example.

  Here, as shown in FIG. 21, the TFT 330A may be formed on the step portion 264A. In this case, the storage capacitor 270A includes a lower capacitor electrode 270a, a capacitor insulating film 270b, and an upper capacitor electrode 270c, and is formed so as to cover the side surface of the step portion 270A. With such a storage capacitor 270A and TFT 330A, the manufacturing process of the liquid crystal device can be simplified.

  As shown in FIG. 22, the lower capacitor electrode 270a and the semiconductor layer 330a constitute one semiconductor layer formed in the same layer on the base film 40. In addition, the capacitor insulating film 270b and the gate insulating film 330b constitute one insulating film. At the time of manufacturing the liquid crystal device according to this example, the lower capacitor electrode 270a and the semiconductor layer 330a are formed simultaneously. In addition, the capacitor insulating film 270b and the gate insulating film 330b are also formed at the same time.

  Therefore, according to the liquid crystal device according to the present example, since the storage capacitor 270A and the TFT 330A can be formed by a common process, the manufacturing process of the liquid crystal device can be simplified and the manufacturing cost can be reduced.

  As shown in FIG. 23, the TFT 330A may be formed on the step portion 264A.

(Modification 4)
Next, the configuration of Modification Example 4 of the liquid crystal device according to the present embodiment will be described with reference to FIG. FIG. 24 is a plan view showing a specific configuration of the liquid crystal device according to this example. The liquid crystal device according to this example is different from the liquid crystal device according to Modification 3 described above in that an upper capacitor electrode 270d is provided instead of the upper capacitor electrode 270c which is a part of the storage capacitor 270A.

  As shown in FIG. 24, according to the liquid crystal device according to this example, the upper capacitor electrode 270d is individually provided for each of the plurality of pixels, and the plurality of pixels are separated from each other. Such upper capacitor electrodes 270d are electrically connected to each other via wiring such as a relay layer (not shown), and are supplied with a predetermined potential.

(Modification 5)
Next, the configuration of Modification Example 5 of the liquid crystal device according to the present embodiment will be described with reference to FIG. FIG. 25 is a plan view showing a specific configuration of the liquid crystal device according to this example. In the liquid crystal device according to this example, a part of the scanning line 11 is used as the gate electrode 11a instead of the gate electrode 330c which is a part of the TFT 330A, as compared with the liquid crystal device according to the fourth modification described above. Is different.

  As shown in FIG. 25, the TFT 330A includes a gate electrode 11a that is a portion of the scanning line 11 extending in the X direction in the drawing and that overlaps the gate insulating film 330b. According to such a TFT 330A, since it is not necessary to form a gate electrode separately from the scanning line 11, there is an advantage that the manufacturing process of the liquid crystal device can be simplified.

(Modification 6)
Next, the configuration of Modification Example 6 of the liquid crystal device according to the present embodiment will be described with reference to FIG. FIG. 26 is a plan view showing a specific configuration of the liquid crystal device according to this example. In the liquid crystal device according to this example, the channel length of the TFT 330A is along the X direction in the drawing as compared with the liquid crystal device according to the fourth modification described above, and the upper capacitor electrode 270d that forms part of the storage capacitor 270A. Is different in that it extends to both pixels adjacent to each other along the X direction in the figure.

  As shown in FIG. 24, according to the liquid crystal device according to this example, the upper capacitor electrode 270d is formed across adjacent pixels along the X direction. According to such an upper capacitive electrode 270d, the upper capacitive electrode provided in each pixel may not be electrically connected via the relay layer.

(Modification 7)
Next, the configuration of Modification Example 7 of the liquid crystal device according to the present embodiment will be described with reference to FIG. FIG. 27 is a plan view showing a specific configuration of the liquid crystal device according to this example. The liquid crystal device according to this example is different from the liquid crystal device according to Modification 6 described above in that the upper capacitor electrodes 270d constituting a part of the storage capacitor 270A are separated from each other in adjacent pixels. Is different.

  As shown in FIG. 27, the upper capacitor electrode 270d is individually provided for each of the plurality of pixels, and the plurality of pixels are separated from each other. Such upper capacitor electrodes 270d are electrically connected to each other via wiring such as a relay layer (not shown).

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal device, 6 ... Data line, 9 ... Pixel electrode, 10 ... TFT array substrate, 10a ... Image display area, 11 ... Scanning line, 30, 130, 230, 330: TFT, 70, 170, 270, 270A ... Retention capacitance

Claims (10)

A plurality of pixels arranged in a pixel region on the substrate;
A transistor element provided for each pixel;
A capacitor element having a first capacitor electrode formed simultaneously from the same semiconductor film as the semiconductor layer of the transistor element, and a second capacitor electrode disposed opposite to the first capacitor electrode;
The electro-optical device, wherein the first capacitor electrode is formed to have a thickness larger than that of the semiconductor layer. The electro-optical device according to claim 1, wherein the capacitive element is formed in a frame shape so as to surround a pixel electrode provided corresponding to the pixel in a plan view. The electro-optical device according to claim 1, wherein the second capacitor electrode is formed across the plurality of pixels. The first capacitor electrode is a plurality of first sub-capacitance electrodes electrically connected to each other;
The capacitive insulating film formed between the first capacitive electrode and the second capacitive electrode is composed of a plurality of sub-capacitor insulating films respectively formed on the plurality of first sub-capacitor electrodes,
4. The electro-optical device according to claim 1, wherein the second capacitor electrode is formed on the plurality of sub-capacitor insulating films. 5. A first sub-capacitor electrode extending along a thickness direction; a third sub-capacitance electrode extending along a substrate surface of the substrate; and electrically connected to the second sub-capacitance electrode; Have
4. The electricity according to claim 1, wherein the capacitor insulating film is formed so as to cover surfaces of the second sub-capacitance electrode and the third sub-capacitance electrode. 5. Optical device. The electro-optical device according to claim 1, wherein the transistor element is a pixel switching element electrically connected to the pixel electrode. A second transistor element constituting a part of a circuit portion provided around the pixel region;
6. The semiconductor layer of the second transistor is formed to have a film thickness larger than that of the first semiconductor layer, and is formed to have substantially the same film thickness as the first capacitor electrode. The electro-optical device according to any one of the above. The semiconductor layer of the pixel switching element is formed such that the width along the substrate surface of the substrate is larger than the thickness along the thickness direction,
The electro-optical device according to claim 6, wherein the electro-optical device is a planar transistor element having a channel region extending in a plane along a substrate surface of the substrate. The semiconductor layer of the second transistor element is formed such that the width along the substrate surface of the substrate is smaller than the thickness along the thickness direction,
The electro-optical device according to claim 7, wherein the electro-optical device is a fin-type transistor element having a channel width along a substrate surface of the substrate. A first step of forming a step in one region on the substrate;
A second step of forming a semiconductor film continuously extending over the upper and side surfaces of the stepped portion and other regions on the substrate;
Forming a first capacitor electrode of a capacitor element covering the upper surface and side surfaces of the step from the semiconductor film, and simultaneously forming a semiconductor layer of a transistor element from the semiconductor film to the other region;
Forming a capacitor insulating film on the first semiconductor layer and simultaneously forming a gate insulating film on the semiconductor layer;
And a fifth step of forming a gate electrode on the gate insulating film simultaneously with forming a second capacitor electrode on the capacitor insulating film.

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