JP2010101934A - Electro-optical device and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a light leakage current in a semiconductor element such as a pixel switching element without increasing a proportion of a non-aperture area in an image display region of a liquid crystal device, for example. <P>SOLUTION: A first interlayer film (41) is formed on a second light-shielding film (11). The first interlayer film (41) has a first protruding part (41a) protruding upward from a TFT array substrate 10, corresponding to the shape of the second light-shielding film (11). The first interlayer film (41) is an insulating film as a base of a semiconductor layer (1a). Therefore, only by forming the first interlayer film (41) on the second light-shielding film (11), a part of the first interlayer film (41) overlapping the second light-shielding film (11) becomes the first protruding part 41a having a shape corresponding to the shape of the second light-shielding film (11). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technical field of, for example, an electro-optical device such as a liquid crystal device and a manufacturing method thereof.

  In a liquid crystal device that is an example of this type of electro-optical device, a light shielding film that shields a TFT provided in each pixel portion as a pixel switching element is often provided on an upper layer side and a lower layer side of the element (Patent Literature). 1). The light-shielding film is provided in a non-opening region that does not transmit light and is provided in a non-opening region that does not transmit light on a substrate on which a semiconductor element such as a TFT is formed. Reduce optical leakage current.

JP 2000-164875 A

  However, when the size of the light-shielding film is increased for the purpose of shielding the TFT by the light-shielding film, the proportion of the non-opening area in the display area for displaying the image increases, and the liquid crystal device displays the image. There arises a problem that the display performance is lowered.

  Therefore, the present invention has been made in view of the above problems and the like. For example, without increasing the ratio of the non-opening area in the display area, more preferably, while reducing the ratio of the non-opening area, the pixel It is an object of the present invention to provide an electro-optical device capable of reducing light leakage current in a semiconductor element such as a switching element, and a manufacturing method thereof.

  In order to solve the above problems, an electro-optical device according to the present invention is formed in a display area on a substrate, and is formed on the protrusion and a protrusion protruding upward from the substrate. A first interlayer film having a first protruding portion protruding upward corresponding to the shape of the protruding portion, and having a width equal to or greater than the width of the protruding portion along one direction on the substrate; And a semiconductor layer overlying the projecting portion on the first projecting portion, electrically connected to another conductive portion provided on the substrate, and formed on the semiconductor layer, A second interlayer film having a second projecting portion projecting upward corresponding to the first projecting portion, and a first layer formed on the second projecting portion and covering the second projecting portion A light shielding film.

  According to the electro-optical device of the present invention, the protruding portion is formed so as to protrude upward from the base film formed in the display area on the substrate, or to protrude upward from the substrate, for example. .

  The first interlayer film is, for example, an insulating film serving as a base for the semiconductor layer, and is formed on the protruding portion. Therefore, only by forming the first interlayer film on the protruding portion, a portion of the first interlayer film that overlaps the protruding portion protrudes upward corresponding to the shape of the protruding portion. Become.

  The semiconductor layer has a width equal to or greater than the width of the protruding portion along one direction on the substrate, and overlaps the protruding portion on the first protruding portion, and is provided on the substrate. It is electrically connected to other conductive parts such as parts.

  The second interlayer film is formed on the semiconductor layer. Therefore, only by forming the second interlayer film on the semiconductor layer, a portion of the second interlayer film that overlaps with the second protruding portion protrudes upward corresponding to the first protruding portion. It becomes the shape part.

  The first light shielding film is formed on the second projecting portion and is formed so as to cover the second projecting portion. Therefore, the first light-shielding film extends along the surface of the second protruding portion that is wider than the width of the semiconductor layer along one direction, and covers the semiconductor layer from the upper side when viewed three-dimensionally. It extends to the periphery of.

  Therefore, according to the electro-optical device of the present invention, the light irradiated from above the substrate toward the semiconductor layer can be efficiently shielded by the first light shielding film. More specifically, compared with the case where a flat light shielding film is formed on the semiconductor layer, the first light shielding film having a narrow width along one direction causes the semiconductor layer and the oblique direction with respect to the semiconductor layer. Light irradiated toward the semiconductor layer can be shielded.

  Therefore, according to the electro-optical device according to the present invention, the opening region narrowed by the first light-shielding film can be prevented from being reduced as much as possible, the display performance of the electro-optical device can be improved, and the semiconductor The light leakage current can be reduced by improving the light shielding property to the layer.

  In one aspect of the electro-optical device according to the aspect of the invention, the protruding portion may be a second light-shielding film that shields light applied to the semiconductor layer from below the semiconductor layer.

  According to this aspect, light irradiated on the semiconductor layer from the lower side of the substrate can also be shielded, and generation of light leakage current can be further reduced.

  In another aspect of the electro-optical device according to the invention, the semiconductor layer constitutes a part of a thin film transistor that is a switching element that performs switching control of each of a plurality of pixel portions constituting the display region, The thin film transistor may be formed in a non-opening region that separates open regions in the display region.

  According to this aspect, it is possible to increase the proportion of the display area occupied by the aperture area, that is, the aperture ratio, and to improve the display performance of the electro-optical device.

  In order to solve the above-described problem, a method of manufacturing an electro-optical device according to the present invention corresponds to a step of forming a protruding portion protruding upward on a substrate in a display area on the substrate, and a shape of the protruding portion. And forming a first interlayer film having a first protrusion protruding upward on the protrusion, and having a width equal to or greater than the width of the protrusion along one direction on the substrate. And a semiconductor layer which overlaps with the protrusion on the first protrusion and is electrically connected to another conductive portion provided on the substrate is formed on the first protrusion. Forming a second interlayer film on the semiconductor layer having a second projecting portion projecting upward corresponding to the first projecting portion, and covering the second projecting portion. Forming a light shielding film on the second protrusion.

  According to the method for manufacturing an electro-optical device according to the present invention, similarly to the above-described electro-optical device, the opening area narrowed by the first light-shielding film can be prevented from being reduced as much as possible, and the display performance of the electro-optical device can be reduced. In addition, it is possible to manufacture an electro-optical device that can reduce the light leakage current by improving the light shielding property with respect to the semiconductor layer.

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

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

<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 of the liquid crystal device 1 as seen from the counter substrate side together with the components formed on the TFT array substrate, and FIG. 2 is a cross-sectional view taken along the line II-II ′ of FIG.

  1 and 2, in the liquid crystal device 1, a TFT array substrate 10 and a counter substrate 20 are disposed to face each other. 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 images that are display regions in which a plurality of pixel portions 72 (see FIG. 3) are provided. They are bonded to each other by a sealing material 52 provided in a sealing area located around the display area 10a.

  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 (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. There is a peripheral area located around the image display area 10a. In other words, particularly in the present embodiment, when viewed from the center of the TFT array substrate 10, the distance from the frame light shielding film 53 is defined as the peripheral region.

  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 area 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.

  Vertical conductive members 106 functioning as vertical conductive terminals between the two substrates are disposed at the four corners of the counter substrate 20. On the other hand, the TFT array substrate 10 is provided with vertical conduction terminals in a region facing these corner portions. 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, an alignment film is formed on the pixel electrode 9a after the pixel switching TFT, the scanning line, the data line and the like are formed. On the other hand, on the counter substrate 20, in addition to the counter electrode 21, a lattice-shaped or striped light-shielding film 23 and an alignment film are formed on the uppermost layer portion. 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.

  1 and 2, on the TFT array substrate 10, in addition to the 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 to obtain data. 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.

<1-2: Electrical configuration of liquid crystal device>
Next, the electrical configuration of the liquid crystal device 1 will be described with reference to FIG. FIG. 3 is an equivalent circuit of various elements, wirings, and the like in a plurality of pixel portions formed in a matrix that forms the image display region 10 a of the liquid crystal device 1.

  In FIG. 3, a pixel electrode 9 a and a TFT 30 are formed in each of a plurality of pixel regions arranged in a matrix that forms the image display region 10 a of the liquid crystal device 1. The TFT 30 is a pixel switching element that is electrically connected to the pixel electrode 9 a and performs switching control of the pixel electrode 9 a made of a transparent conductive film such as ITO during the operation of the liquid crystal device 1. 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 3a is electrically connected to the gate of the TFT 30, and the liquid crystal device 1 sequentially applies the scanning signals G1, G2,..., Gm to the scanning line 3a in a pulse sequence in this order at a predetermined timing. It is comprised so that it may apply. 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 contained in the liquid crystal layer 50 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 with respect to light is increased, and light having a contrast corresponding to an image signal is emitted from the liquid crystal device 1 as a whole. In the storage capacitor 70, one capacitor electrode is electrically connected to the fixed potential line 300 and the other capacitor electrode is electrically connected to the pixel electrode 9a in order to prevent the image signal from leaking. . Such a storage capacitor 70 is added in parallel with a liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode.

<1-3: Specific Configuration of Pixel Unit>
A specific configuration of the pixel unit 72 will be described with reference to FIGS. 4 and 5. FIG. 4 is a plan view showing a partial configuration of the image display area 10a. 5 is a cross-sectional view taken along the line VV ′ of FIG. In FIG. 4, the components of the liquid crystal device 1 provided on the upper layer side of the light shielding film 25 and the lower layer side of the semiconductor layer 1a are not shown for convenience of explanation, and are adjacent to each other. Four matching pixel parts are shown.

  As shown in FIG. 4, on the TFT array substrate 10 of the liquid crystal device 1, a plurality of transparent pixel electrodes 9a (contours are indicated by dotted line portions 9a ′) in a matrix along each of the X direction and the Y direction. And data lines (not shown) and scanning lines 3a are provided along the vertical and horizontal boundaries of the pixel electrode 9a. In the image display area 10a on the TFT array substrate 10, the data lines extending in the vertical and horizontal directions, the opaque wiring such as the scanning lines 3a, and the area where the first light shielding film 25 is formed are substantially in the image display area 10a. This is a non-opening region where light is not transmitted. In addition, an area where light contributing to image display can be transmitted in the pixel area is an opening area (see FIG. 5). The pixel switching TFT 30 is provided in each of the regions where the scanning line 3a and the data line overlapping the first light shielding film 25 intersect each other.

  Of the scanning line 3a, a portion that is a part of the semiconductor layer 1a and overlaps with the channel region 1c indicated by the hatched region rising to the right in FIG. 4 is the gate electrode 3a2 of the TFT 30. The gate electrode 3a2 is formed by patterning a conductive film such as a metal film.

  The TFT 30 includes a semiconductor layer 1a extending along the Y direction that is the channel length direction. The semiconductor layer 1a is an example of the “semiconductor layer” in the present invention. The semiconductor layer 1a includes a gate electrode 3a2, a channel region 1c in the semiconductor layer 1a in which a channel is formed by an electric field from the scanning line 3a, a source region 1s and a drain region 1d provided on both sides of the channel region 1c, Contact portions 1f and 1g are provided. The TFT 30 may have an LDD (Lightly Doped Drain) structure. According to the TF 30 having the LDD structure, the TFT 30 transistor can operate at high speed, and the display performance of the liquid crystal device 1 can be improved. The TFT 30 is electrically connected to the data line via a contact hole 81 electrically connected to the contact portion 1f, and the pixel electrode 9a via a contact hole 83 electrically connected to the contact portion 1g. Is electrically connected. Therefore, according to the TFT 30, it is possible to reliably supply the image signal to the pixel electrode 9a by switching control of the pixel portion by the TFT 30, and it is possible to display a high-quality image corresponding to the image signal.

  As shown in FIG. 5, the liquid crystal device 1 includes the second light shielding film 11, the first interlayer film 41, the semiconductor layer 1 a, the second interlayer film 42, and the light shielding film 25, which are examples of the “projection” of the present invention. I have.

  The second light shielding film 11 is formed so as to protrude upward in the figure from the TFT array substrate 10. Such a second light shielding film 11 shields light applied to the semiconductor layer 1a from below the semiconductor layer 1a. Therefore, according to the second light shielding film 11, it is possible to reduce the light leakage current that may be generated in the semiconductor layer 1 a during the operation of the liquid crystal device 1.

  The first interlayer film 41 is formed on the second light shielding film 11. The first interlayer film 41 has a first protruding portion 41 a that protrudes upward from the TFT array substrate 10 in the drawing corresponding to the shape of the second light shielding film 11. Such a first interlayer film 41 is an insulating film serving as a base for the semiconductor layer 1a. Therefore, only the first interlayer film 41 is formed on the second light shielding film 11, and the portion of the first interlayer film 41 that overlaps the second light shielding film 11 has a shape corresponding to the shape of the second light shielding film 11. It becomes the 1st protrusion part 41a. The semiconductor layer 1a has a width W2 that is equal to or larger than the width W1 of the second light shielding film 11 along the X direction in the drawing, and overlaps the second light shielding film 11 on the first protrusion 41a.

  The second interlayer film 42 is formed on the semiconductor layer 1a, and has a second protruding portion 42a that protrudes upward from the TFT array substrate 10 corresponding to the first protruding portion 41a. Therefore, only by forming the second interlayer film 42 on the semiconductor layer 1a, the portion of the second interlayer film 42 that overlaps the first protrusion 41a corresponds to the first protrusion 41a and is located above the TFT array substrate 10. It becomes the 2nd protrusion part 42a which protruded toward. Here, since the width W2 of the semiconductor layer 1a is greater than or equal to the width W1 of the second light shielding film 11, the surface of the second projecting portion 42a covers the semiconductor layer 1a in three dimensions. Is formed.

  The first light shielding film 25 is formed on the second protrusion 42a and covers the second protrusion 42a. That is, the surface of the second projecting portion 42a extends to the periphery of the semiconductor layer 1a so as to cover the semiconductor layer 1a in three dimensions. The first light shielding film 25 has a width W3 that is greater than the width W2 along the surface of the second protrusion 42a. On the first light shielding film 25, the third interlayer film 43, the pixel electrode 9a, and the alignment film 16 are formed. Note that illustration of components such as the liquid crystal layer 50 on the alignment film 16 is omitted.

  Therefore, according to the liquid crystal device 1, the light irradiated toward the semiconductor layer 1 a from above the TFT array substrate 10 can be efficiently shielded by the first light shielding film 25. More specifically, even if the first light shielding film 25 having a width smaller than the width of the flat light shielding film along the X direction is provided, the first light shielding film 25 is equal to or more than the flat light shielding film. Will have sex. That is, according to the first light shielding film 25, light irradiated toward the semiconductor layer 1a from each of the semiconductor layer 1a and the oblique direction with respect to the semiconductor layer 1a can be shielded with the width thereof reduced as much as possible.

  Therefore, according to the liquid crystal device 1, the opening area narrowed by the first light shielding film 25 can be prevented from being narrowed as much as possible, and the display performance of the liquid crystal device 1 can be improved. More specifically, the ratio occupied by the aperture area in the image display area 10a, that is, the aperture ratio can be increased, and the display performance of the electro-optical device can be improved. In addition, according to the liquid crystal device 1, the light leakage current can be reduced by improving the light shielding property to the semiconductor layer 1a.

<2: Manufacturing method of liquid crystal device>
Next, a manufacturing method of a liquid crystal device for manufacturing the liquid crystal device 1 will be described with reference to FIGS. 6 and 7 are process cross-sectional views sequentially showing main processes of the method of manufacturing the liquid crystal device according to the present embodiment.

  As shown in FIG. 6A, the second light-shielding film 11 protruding upward on the TFT array substrate 10 is formed in a region to be the image display region 10a on the TFT array substrate 10.

  Next, as shown in FIG. 6B, a second interlayer film 41 is formed so as to overlap the second light shielding film 11. At this time, by forming the first interlayer film 41 so as to overlap the second light shielding film 11, the first projecting portion projecting upward of the TFT array substrate 10 corresponding to the shape of the second light shielding film 11. 41a is formed.

  Next, as shown in FIG. 6C, the second light shielding film 11 has a width W2 equal to or larger than the width W1 of the second light shielding film 11 along the X direction, and overlaps the second light shielding film 11 on the first protrusion 41a. The semiconductor layer 1a is formed. The semiconductor layer 1a is formed by forming a semiconductor layer such as a polysilicon film on the first interlayer film 41 and then patterning the semiconductor layer. In order to electrically connect the semiconductor layer 1a and the contact hole 81, etc., the second interlayer film 42 is formed on the semiconductor layer 1a, and then the interlayer film is partially removed to form a hole. Then, a conductive film may be formed therein.

  Next, as shown in FIG. 7D, a second interlayer film 42 is formed on the semiconductor layer 1a. As a result, a second protruding portion 42a that protrudes upward from the TFT array substrate 10 corresponding to the first protruding portion 41a is formed.

  Next, as shown in FIG. 7E, the first light-shielding film 25 is formed on the second protruding portion 42a so as to cover the second protruding portion 42a. The first light shielding film 25 can be formed by forming a light shielding film on the second interlayer film 42 and then patterning the film. Thereafter, the third interlayer film 43 and the like to be formed on the first light shielding film 25 are sequentially formed, and the liquid crystal device 1 is formed by sandwiching the liquid crystal layer 50 between the TFT array substrate 10 and the counter substrate 20.

  Therefore, according to the method for manufacturing the liquid crystal device according to the present embodiment, the opening region narrowed by the first light shielding film 25 can be minimized as much as the liquid crystal device 1 described above. It is possible to manufacture an electro-optical device capable of improving the display performance and reducing the light leakage current by improving the light shielding property with respect to the semiconductor layer 1a.

It is a top view which shows the whole structure of the liquid crystal device which concerns on this embodiment. It is II-II 'sectional drawing of FIG. 4 is an equivalent circuit of various elements, wirings, and the like in a plurality of pixel portions formed in a matrix that forms an image display region of the liquid crystal device according to the present embodiment. It is a top view of the pixel part of the liquid crystal device concerning this embodiment. It is VV 'sectional drawing of FIG. It is process top view (the 1) which showed in a turn the main processes of the manufacturing method of the liquid crystal device concerning this embodiment. It is process top view (the 2) which showed the main process of the manufacturing method of the liquid crystal device concerning this embodiment in order.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal device, 1c ... Channel region, 1s ... Source region, 1d ... Drain region, 1f, 1g ... Contact part, 3a2 ... Gate electrode, 10 ... TFT array Substrate, 20 ... counter substrate, 11, 25 ... light shielding film, 30 ... TFT, 41 ... first interlayer film, 42 ... second interlayer film

Claims (4)

Formed in a display area on the substrate, and a protruding portion protruding upward of the substrate;
A first interlayer film formed on the projecting portion and having a first projecting portion projecting upward corresponding to the shape of the projecting portion;
It has a width equal to or larger than the width of the protruding portion along one direction on the substrate, and overlaps the protruding portion on the first protruding portion, and is connected to another conductive portion provided on the substrate Electrically connected semiconductor layers;
A second interlayer film formed on the semiconductor layer and having a second projecting portion projecting upward corresponding to the first projecting portion;
An electro-optical device comprising: a first light-shielding film formed on the second projecting portion and covering the second projecting portion. The electro-optical device according to claim 1, wherein the protruding portion is a second light shielding film that shields light applied to the semiconductor layer from below the semiconductor layer. The semiconductor layer constitutes a part of a thin film transistor that is a switching element that controls switching of each of a plurality of pixel portions constituting the display region,
The electro-optical device according to claim 1, wherein the thin film transistor is formed in a non-opening region that separates open regions in the display region. Forming a protrusion protruding upward from the substrate in a display area on the substrate;
Forming a first interlayer film on the protruding portion having a first protruding portion protruding upward corresponding to the shape of the protruding portion;
It has a width equal to or greater than the width of the protruding portion along one direction on the substrate, and overlaps the protruding portion on the first protruding portion, and other conductive portions provided on the substrate Forming an electrically connected semiconductor layer on the first protrusion;
Forming a second interlayer film on the semiconductor layer having a second projecting portion projecting upward corresponding to the first projecting portion;
And a step of forming a first light-shielding film covering the second projecting portion on the second projecting portion.

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