JP2010066393A - Method for manufacturing electro-optical device, electro-optical device, and electronic equipment - Google Patents

Abstract

In a manufacturing method of an electro-optical device such as a liquid crystal device, a manufacturing method having a stacked structure in which a new layer can be stacked with high quality on a plurality of electrodes formed on an insulating film is facilitated.
An electro-optical device manufacturing method has a convex shape extending on at least one of a first direction and a second direction intersecting each other on one of a pair of substrates (10, 20). A step of forming an insulating film (12) having a step (12a), a step of forming a conductive layer on the insulating film in a solid shape, and patterning the conductive layer so that a convex step is exposed, Dividing the conductive layer into a plurality of island-shaped electrodes (9).
[Selection] Figure 5

Description

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

  A liquid crystal device which is an example of this type of electro-optical device is configured by sandwiching a liquid crystal which is an example of an electro-optical material between a pair of substrates. On the surface of each substrate facing the liquid crystal, an alignment film that has been subjected to a rubbing process for restricting alignment molecules to a predetermined alignment state is formed. Further, in an element substrate on which a TFT or the like that functions as a switching element is formed, a pixel electrode for controlling the voltage of the alignment state of the liquid crystal is formed on the lower layer side of the alignment film.

  The pixel electrode is formed in an island shape on a flat insulating film serving as a base, and a step corresponding to the thickness of the pixel electrode is generated between the surface of the pixel electrode and the surface of the insulating film. When an alignment film is laminated on such a step, the alignment film does not make good contact with the base side in the vicinity of the step, or stress cracks occur due to the passage of time or external impact, and the inside of the alignment film Will cause defects. In particular, the larger the level difference, the more remarkable the occurrence of such defects. For this reason, a technique is disclosed in which an insulating film is stacked on the pixel electrode and the surface of the insulating film is polished so that the surface in contact with the alignment film is flat (see Patent Document 1).

Japanese Patent Laid-Open No. 10-270707

  However, according to the above-described background art, the flattened surface is contaminated by the polished insulating film residue and the like, so that the alignment film stacked on the upper layer still has a certain number of defects. As a solution to this, it may be possible to remove the residue by cleaning the surface of the polished insulating film. However, it is necessary to change the cleaning liquid and the cleaning method depending on the type of insulating film. There are many problems. In addition, there is a problem in that it is difficult to completely remove the cleaning liquid itself by simply cleaning the surface of the insulating film, and the remaining material remains on the surface.

  The present invention has been made in view of the above problems, for example. An electro-optical device having a stacked structure in which a new layer can be stacked with high quality on a plurality of electrodes formed on an insulating film is easily provided. It is an object of the present invention to provide a method for manufacturing an electro-optical device that can be manufactured, an electro-optical device manufactured by the manufacturing method, and an electronic apparatus including such an electro-optical device.

  In order to solve the above problems, an electro-optical device manufacturing method of the present invention is an electro-optical device manufacturing method in which an electro-optical material is sandwiched between a pair of substrates, on one of the pair of substrates, A first step of forming an insulating film having a convex step so as to extend in at least one of a first direction and a second direction intersecting with each other; and the convex step on the insulating film. A second step of forming the conductive layer in a solid shape so as to have a step corresponding to the surface, and patterning the conductive layer so that the convex step is exposed, thereby forming the conductive layer into a plurality of island shapes And a third step of dividing the electrode.

  The electro-optical device that can be manufactured according to the present invention has an electro-optical material such as liquid crystal sandwiched between a pair of substrates, and controls the operation state of the electro-optical material, for example, an electro-optical operation such as image display. I do.

  In the first step, for example, an insulating film having a convex step on the surface is formed on one substrate such as a TFT array substrate or an element substrate. Here, the convex steps may be formed in at least one of the first direction and the second direction, and may be formed in a lattice shape along both the first direction and the second direction. It may be formed in a stripe shape along one direction, or may be a matrix shape with a part missing. Such a convex step can be easily formed, for example, by first forming an insulating film flat and then patterning the surface.

  In the second step, the conductive layer is formed in a solid shape on the insulating film formed in the first step. Here, since a convex step is formed on the surface of the insulating film, when the conductive layer is formed in a solid shape on the insulating film, a corresponding step is also generated on the surface of the conductive layer. Note that the size of the convex step on the surface of the insulating film and the size of the step on the surface of the conductive layer do not necessarily match, and the latter is typically the same as or smaller than the former.

  In the third step, a plurality of island-shaped electrodes are formed from the conductive layer by patterning the solid conductive layer on the insulating film so that the convex steps on the surface of the insulating film are exposed. . Here, the “island shape” is typically a rectangular shape or a polygonal shape close to a square, or a shape similar thereto, but may be an elongated island shape (ie, a stripe shape).

  In the electro-optical device manufactured by the above steps, a convex step formed on the surface of the insulating film is exposed between adjacent electrodes. Therefore, the step between the surface of the electrode and the surface of the insulating film can be formed smaller than in a typical electro-optical device in which such a step is not exposed. In other words, the presence of a convex step on the insulating film can significantly reduce the size of the step between the surface of the electrode and the surface of the insulating film. As a result, even when a new layer is stacked on the electrode and the insulating film, the step on the base side is small, so that the contact with the base side can be kept good. Therefore, according to the manufacturing method of the present invention, an electro-optical device that can effectively suppress the occurrence of stress cracks due to the passage of time or external impact or the occurrence of defects inside the alignment film is manufactured. be able to.

  In one aspect of the method of manufacturing the electro-optical device according to the aspect of the invention, the third step includes a resist film forming step of forming a resist film on the conductive layer, and the convex shape when viewed in plan on the substrate. Etching step for removing the conductive layer by etching so that the step is exposed, and a resist film removing step for removing the resist film remaining on the electrode.

  According to this aspect, the process for dividing the solid conductive layer formed on the insulating film into the island-shaped electrodes includes the following three processes (ie, the resist film forming process, the etching process, and the resist film removal). Process).

  In the resist film forming step and the patterning step, a resist film is applied on the conductive layer formed in a solid shape on the insulating film. Here, the resist film may be applied, for example, so that the surface thereof is flat. If the resist film is formed in this way, a step is formed on the surface of the conductive layer so as to correspond to the step on the insulating film, so that the surface of the conductive layer is convex when viewed in plan on the substrate. The resist film is formed thin in a region that is raised in a shape. On the other hand, the resist film is formed thick in a region where the surface of the conductive layer is recessed when viewed in plan on the substrate. By forming the resist film in this manner, the region where the resist film is formed thin is exposed faster than the region where the resist film is formed thick. That is, the region where the resist film is thin is more sensitive than the region where the resist film is thick. Therefore, the surface of the underlying convex structure can be easily exposed by performing exposure. Furthermore, because of the surface free energy, the resist space structure for dividing the conductive layer into a plurality of island-shaped electrodes opened by the exposure and development process is attracted to the underlying convex structure. Therefore, the surface of the conductive layer having the base convex structure to be processed by etching can be accurately exposed.

  In the etching step, the conductive layer formed in a solid shape is divided into a plurality of island-shaped electrodes by etching the conductive layer from above the resist film. Here, the conductive layer formed on the insulating film is etched so that the convex steps on the surface of the insulating film are exposed. In the resist film forming process and the patterning process, since the conductive layer on the surface of the base convex structure is already exposed, the conductive layer on the surface of the convex structure formed on the base insulating film can be easily etched, and the insulating film A convex step on the surface can be exposed, and the conductive layer can be divided into a plurality of island-shaped electrodes.

  Such etching is performed for a period of time determined experimentally or empirically until the convex step on the surface of the insulating film is exposed by a predetermined amount. That is, it is implemented by time management. Alternatively, in such etching, the convex step on the surface of the insulating film itself is used as an etching stopper, and the exposure here is monitored by monitoring the exposure to a greater or lesser extent by an optical method or the like. This is done until it is detected.

  In the resist film removing step, the resist film remaining on the electrode patterned by etching is removed. For example, it may be removed by dissolving the resist film with a solvent, or may be peeled off by baking.

  By patterning the electrodes using the resist film in this manner, it is possible to more easily form a plurality of island-shaped electrodes from the conductive layer.

  In another aspect of the method for manufacturing the electro-optical device according to the aspect of the invention, a fourth step of forming an operation regulating film that regulates an operation state of the electro-optical material on the plurality of island-shaped electrodes and the convex steps. Is further provided.

  According to this aspect, in the fourth step, the operation restricting film is further formed on the step between the surface of the electrode and the surface of the insulating film. Here, “on the plurality of island-shaped electrodes and the convex steps” typically means “on one surface of the plurality of island-shaped electrodes and the convex steps or on top of them. Although it means “on one side”, it is not excluded even when it is not locally formed, for example, a part of the peripheral part.

  The “electro-optical material” is, for example, liquid crystal, the “operation state” is, for example, an alignment state, and the “operation regulating film” is, for example, an alignment film. In this case, according to this aspect, for example, on the element substrate or the TFT array substrate (that is, typically a substrate on which a thin film transistor, a data line, a scanning line, and the like are formed), the first along the data line and the scanning line. Forming an insulating film having a convex step in the first direction and the second direction, forming a pixel electrode in a region surrounded by the convex step, and forming an alignment film on the pixel electrode and the insulating film. An electro-optical device can be manufactured.

  Since the operation regulating film formed in this way is formed on a small step between the surface of the electrode and the surface of the insulating film, it is possible to maintain good contact with the base side (that is, the electrode and the insulating film). it can. As a result, it is possible to manufacture an electro-optical device that can effectively suppress the occurrence of stress cracks due to the passage of time or external impact or the occurrence of defects in the alignment film.

  In the aspect of forming the operation restricting film described above, a step of forming a passivation film on the plurality of island-shaped electrodes and the convex step may be further included before the fourth step.

  In this aspect, before forming the operation restricting film, the passivation film is formed on the plurality of island-shaped electrodes serving as the base of the operation restricting film and the convex steps on the surface of the insulating film. Thereby, it is possible to further reduce the convex steps on the surfaces of the electrode and the insulating film. In other words, as described above, a certain level difference is reduced by arranging the convex level difference on the surface of the insulating film so as to be exposed between adjacent electrodes. In this aspect, a passivation film is provided. Thus, the step can be further reduced. As a result, it is possible to further reduce the number of defects generated in the operation regulating film formed on the upper layer side, and it is possible to extremely effectively reduce poor alignment of the electro-optical material sandwiched between the substrates. Note that the passivation film also has a function as a general-purpose protective film or planarization film.

  In another aspect of the method of manufacturing the electro-optical device according to the aspect of the invention, the convex step is formed in a lattice shape along a first direction and a second direction intersecting each other on the surface of the insulating film. .

  According to this aspect, the convex step formed on the insulating film is formed on the lattice along two intersecting directions. That is, since the convex step is formed along the boundary between adjacent electrodes, for example, a manufacturing method suitable for manufacturing an active matrix liquid crystal device in which a pixel electrode formed for each pixel is formed is realized. be able to.

  In yet another aspect, in the third step, the conductive layer is patterned so that the side surface of the conductive layer is in contact with the surface of the side wall of the convex step. As described above, if the conductive layer is removed so that the conductive layer remains on the side wall, the step between the surface of the conductive layer and the surface of the step on the insulating film can be further reduced. As a result, it is possible to further reduce the number of defects generated in the operation regulating film formed on the upper layer side, and it is possible to extremely effectively reduce the alignment failure of the electro-optic material sandwiched between the substrates.

  In order to solve the above problems, the electro-optical device of the present invention is formed on one of the pair of substrates that sandwich the electro-optical material, and the first direction and the second direction intersecting each other. An insulating film having a convex step so as to extend in at least one direction, and a plurality of island-shaped electrodes formed on the insulating film and separated from each other by the convex step With.

  In the electro-optical device of the present invention, an electro-optical material such as liquid crystal is sandwiched between a pair of substrates. A convex step is provided on the surface of the insulating film formed in a specific region on the substrate, and island-shaped electrodes are formed on the insulating film so that the step is exposed. In particular, each electrode is partitioned by a convex step formed on the insulating film.

  In addition, since there is a convex step formed by an insulating film between adjacent electrodes, there is a step generated on the surface of the electrode and the insulating film compared to the case where there is no step on the insulating film. It is formed small. Therefore, when a new layer is stacked on the electrode and the insulating film, defects are less likely to occur in the new layer due to a step in the base layer (that is, the electrode and the insulating film). As a result, higher-quality electro-optical operation is finally possible.

  In one aspect of the electro-optical device of the present invention, the electro-optical device further includes an operation restricting film that is formed on the plurality of island-shaped electrodes and the convex step and restricts an operation state of the electro-optical material.

  According to this aspect, for example, an insulating film having a convex step in the first direction and the second direction along the data line and the scanning line is formed on the element substrate, and is surrounded by the convex step. An electro-optical device can be manufactured by forming a pixel electrode in the region and forming an alignment film over the pixel electrode and the insulating film. Since the operation regulating film is formed on a small step between the surface of the electrode and the surface of the insulating film, it is possible to maintain good contact with the base side (that is, the electrode and the insulating film). As a result, it is possible to effectively suppress the occurrence of stress cracks due to the passage of time or external impact, or the occurrence of defects inside the alignment film.

  In the aspect provided with the operation restricting film described above, a passivation film laminated on the plurality of island-shaped electrodes and the convex step and below the operation restricting film may be further provided.

  According to this aspect, the plurality of island-shaped electrodes serving as the base of the operation regulating film and the convex steps on the surface of the insulating film can be further reduced by the passivation film, so that the operation regulating film with fewer defects can be obtained. As a result, an even higher quality electro-optic operation can be realized.

  In another aspect of the electro-optical device according to the aspect of the invention, the plurality of island-shaped electrodes are formed so that side surfaces thereof are in contact with the surface of the side wall of the convex step.

  According to this aspect, since the conductive layer remains on the side wall portion of the convex step formed on the insulating film, the step between the surface of the conductive layer and the surface of the step on the insulating film can be further reduced. it can. Therefore, when a new layer is stacked on the electrode and the insulating film, the new layer is further less likely to be defective due to a step in the base layer (that is, the electrode and the insulating film).

  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, since it includes the electro-optical device of the present invention described above, a projection display device, a television, a mobile phone, an electronic notebook, a word processor, capable of performing high-quality image display, Various electronic devices such as a viewfinder type or a monitor direct-view type video tape recorder, a workstation, a videophone, a POS terminal, and a touch panel can be realized. In addition, as an electronic apparatus of the present invention, for example, an electrophoretic device such as electronic paper, an electron emission device (Field Emission Display and Conduction Electron-Emitter Display), and a display device using these electrophoretic device and electron emission device are realized. Is also possible.

  The operation and other advantages of the present invention will become apparent from the best mode for carrying out the invention described below.

  Hereinafter, a method for manufacturing an electro-optical device according to the present invention will be described based on embodiments.

<1. Liquid crystal device>
First, an overall configuration of a liquid crystal device manufactured by the method for manufacturing an electro-optical device according to the present embodiment will be described.

<1-1. First Embodiment>
FIG. 1 is a plan view showing the overall configuration of the liquid crystal 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 liquid crystal device according to the present embodiment, a TFT array substrate 10 and a counter substrate 20 are arranged 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 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 bead is dispersed for setting the distance between the TFT array substrate 10 and the counter substrate 20 (that is, the inter-substrate gap) to a predetermined value.

  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 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 sampling circuit 7 is provided so as to be covered with the frame light shielding film 53 on the inner side of the seal region along the one side. 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.

  On the TFT array substrate 10, vertical conduction terminals 106 for connecting the two substrates with the vertical conduction material 107 are arranged in regions facing the four corner portions of the counter substrate 20. 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 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 made of a transparent material such as ITO (Indium Tin Oxide) are provided in a matrix on the upper layer of pixel switching TFTs, scanning lines, data lines and the like. An alignment film (not shown in FIG. 2) is formed on the pixel electrode 9. On the other hand, a black matrix 23 is formed on the surface of the counter substrate 20 facing the TFT array substrate 10. The black matrix 23 is formed of, for example, a light-shielding metal film or the like, and is patterned in, for example, a lattice shape or a stripe shape in the image display region 10a on the counter substrate 20. On the light shielding film 23, a counter electrode 21 made of a transparent material such as ITO is formed across the entire surface of the counter substrate 20 (for example, in a solid shape) so as to face the plurality of pixel electrodes 9. An alignment film is formed on the counter electrode 21.

  A liquid crystal layer 50 is formed between the TFT array substrate 10 and the counter substrate 20 that are configured as described above and are arranged so that the pixel electrode 9 and the counter electrode 21 face each other. 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 FIG. 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, a plurality of data lines are precharged at a predetermined voltage level. There may be formed a precharge circuit for supplying a signal prior to an image signal, an inspection circuit for inspecting quality, defects, etc. of the electro-optical device during manufacturing or at the time of shipment, an inspection pattern, and the like.

  Next, the electrical configuration of the image display area of the liquid crystal device according to the first 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 liquid crystal device according to the first embodiment.

In FIG. 3, a pixel electrode 9 and a pixel switching TFT 30 as an example of a “transistor” according to the present invention are formed in each of a plurality of pixels formed in a matrix form constituting the image display region 10a. . The TFT 30 is electrically connected to the pixel electrode 9, and performs switching control of the pixel electrode 9 when the liquid crystal device according to the present embodiment operates. 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 according to the present embodiment applies the scanning signals G1, G2,..., Gm to the scanning line 11 in a pulsed manner at a predetermined timing. It is configured to apply in a line sequential order. The pixel electrode 9 is electrically connected to the drain of the TFT 30, and the image signal S1, S2,..., Sn supplied from the data line 6 is obtained by closing the switch of the TFT 30 serving as a switching element for a certain period. It 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 electrically in parallel with the liquid crystal capacitor formed between the pixel electrode 9 and the counter electrode 21 (see FIG. 2). ing.

  Next, a specific configuration of the pixel electrode 9 of the liquid crystal device will be described with reference to FIG. FIG. 4 is a perspective view showing a three-dimensional structure example of the pixel electrode 9 formed on the TFT array substrate 10 together with the interlayer insulating film 12 formed on the lower layer side of the pixel electrode 9. FIG. 4 is an enlarged view of the TFT array substrate 10 of FIG. 2 obliquely from above, and the detailed structure of the pixel electrode 9 and the interlayer insulating film 12 is omitted for convenience of explanation.

  As shown in FIG. 4, the pixel electrodes 9 are arranged in a matrix with the step on the interlayer insulating film 12 arranged in two vertical and horizontal directions (that is, in a lattice shape along the data lines and the scanning lines) as a boundary. Has been. That is, the convex step 12a formed on the surface of the interlayer insulating film 12 is formed in a non-opening region along the data line and the scanning line, and separates each pixel electrode 9 from each other.

  Next, with reference to FIG. 5, the laminated structure on the TFT array substrate 10 will be described in detail along with the alignment state of the alignment molecules in the liquid crystal 50 sandwiched between the substrates. Here, FIG. 5 is a schematic cross-sectional view in a direction perpendicular to the data line 6 of the image display area 10a.

  In FIG. 5, an interlayer insulating film 12 is formed on the TFT array substrate 10. A convex step 12 a is formed on the surface of the interlayer insulating film 12. A pixel electrode 9 is formed in an island shape between adjacent convex steps 12a. That is, the convex step 12 a is formed so as to partition the plurality of pixel electrodes 9. Note that, for example, switching thin film transistors and wirings may be formed on the surface of the TFT array substrate 10 in advance.

  Here, the surface of each pixel electrode 9 has a non-smooth structure as surrounded by a dotted line in FIG. Such a surface shape is generated by a manufacturing process of the pixel electrode 9 described later.

  A passivation film 14 is laminated on the interlayer insulating film 12 and the pixel electrode 9, and an alignment film 15 is formed thereon. By providing the passivation film 14 in this way, the step difference between the convex step 12a portion of the interlayer insulating film 12 and the pixel electrode 9 in the vicinity thereof is reduced.

  On the other hand, the counter electrode 20 is formed in a solid shape on the counter substrate 20 (lower side in FIG. 5), and an alignment film 25 is laminated on the upper layer side (lower side in FIG. 5).

  In this way, a stacked structure is formed on each of two opposing substrates (that is, the TFT array substrate 10 and the counter substrate 20), and the liquid crystal 50 is sandwiched between these substrates. In the liquid crystal device thus formed, for example, the alignment molecules of the liquid crystal 50 form, for example, the alignment state shown in FIG. 5 at a certain time during operation.

  Here, FIG. 6 is a schematic diagram showing a cross-sectional structure in the image display region of the liquid crystal device of the comparative example. In the comparative example of FIG. 6, the pixel electrode 9 has a smooth surface. Further, unlike the liquid crystal device according to the present embodiment, there is no convex step on the surface of the interlayer insulating film 12 and no passivation film is provided on the pixel electrode 9 and the interlayer insulating film 12. Yes.

  In the liquid crystal device shown in FIG. 6, since the pixel electrode 9 is formed in a plane, the surface of the pixel electrode 9 and the interlayer insulation are formed at the end of each pixel electrode 9 (that is, the region surrounded by the dotted line in FIG. 6). The level difference from the surface of the film 12 is large. Therefore, the alignment film 15 formed on the pixel electrode 9 and the interlayer insulating film 12 does not make good contact with the pixel electrode 9 or the interlayer insulating film 12 in the vicinity of the region surrounded by the dotted line in FIG. Stress cracks may occur inside the alignment film 15 due to the progress or impact from the outside. In addition, such a large step may cause a gap between the base layer (that is, the pixel electrode 9 and the interlayer insulating film 12) when the alignment film 15 is formed, and the alignment film may be easily peeled off. Become. As described above, in the comparative example, defects are likely to occur in the alignment film 15 stacked on the upper layer side in the vicinity of the region surrounded by the dotted line in FIG. As a result, as shown in FIG. 6, the alignment state of the alignment molecules in the liquid crystal 50 is greatly disturbed in the vicinity of the boundary region between adjacent pixels, and the quality of the display image is deteriorated.

  On the other hand, returning to FIG. 5, in the liquid crystal device according to the present embodiment, the pixel electrode 9 is formed so as to be in contact with the side wall portion 12 ′ of the convex step 12 a formed in the interlayer insulating film 12. The level difference between the surface of the film 12 and the pixel electrode 9 is much smaller than in the case of FIG. That is, in the present embodiment, the step between the pixel electrode 9 and the interlayer insulating film 12 is reduced by the presence of the convex step 12 a in the interlayer insulating film 12.

Further, a passivation film 14 is interposed between the interlayer insulating film 12 and the pixel electrode 9 and the alignment film 15. Due to the presence of the passivation film 14, the level difference between the surfaces of the interlayer insulating film 12 and the pixel electrode 9 is further reduced. That is, as in the comparative example shown in FIG. 6, the presence of a large step in the base layer of the alignment film 15 does not easily cause defects in the alignment film 15. As apparent from the comparison with the comparative example of FIG. 6, according to the liquid crystal device of this embodiment, the disorder of the alignment molecules constituting the liquid crystal 50 can be extremely reduced as shown in FIG. 5. Thus, a liquid crystal device capable of displaying a high-quality image can be realized.
<1-2. Second Embodiment>
Next, a liquid crystal device according to a second embodiment will be described with reference to FIG. FIG. 7 is a schematic cross-sectional view in a direction perpendicular to the data line 6 of the image display area 10a.

  In this embodiment, as shown in FIG. 7, the side wall of the pixel electrode 9 is formed so as not to contact the side wall portion 12 'of the convex step 12a on the surface of the interlayer insulating film 12 formed on the TFT array substrate 10. This is different from the first embodiment. In particular, in the present embodiment, a gap (that is, a region surrounded by a dotted line in FIG. 7) between the surface 12 ′ of the side wall of the convex step 12a and the side wall of the pixel electrode 9 is formed narrow. If the gap between the surface 12 ′ of the side wall of the convex step 12 a and the side wall of the pixel electrode 9 (ie, the region surrounded by the dotted line in FIG. 7) is wide, the case of the comparative example shown in FIG. Similarly, since the step becomes large, a defect is easily generated in the alignment film 15 and a good image display cannot be performed. However, as shown in FIG. 7, if the gap between the surface 12 'of the side wall of the convex step 12a and the side wall of the pixel electrode 9 (that is, the region surrounded by the dotted line in FIG. 7) is formed sufficiently small, the alignment film It is not the size of the convex step 12 a of the interlayer insulating film 12 that mainly affects the number of 15 defects, but the upper side portion of the pixel electrode 9 formed in a substantially trapezoidal shape and the convex shape of the interlayer insulating film 12. This is a step with the surface of the step 12a (the upper side of the convex step). Therefore, as shown in FIG. 7, the step between the upper side portion of the pixel electrode 9 formed in a substantially trapezoidal shape and the surface of the convex step 12a of the interlayer insulating film 12 (the upper side portion of the convex step) is small. Is formed. Therefore, also in this embodiment, the number of defects included in the alignment film 15 can be suppressed. As a result, as shown in FIG. 7, the alignment molecules in the liquid crystal 50 exhibit a good alignment state in almost all regions, and a liquid crystal device capable of high-quality image display with little disturbance can be realized.

<2. Manufacturing method of liquid crystal device>
Next, a method for manufacturing the liquid crystal device according to the embodiment described above will be described with reference to FIGS.

  First, the manufacturing process of the laminated structure on the TFT array substrate 10 in the first embodiment will be described for each process. As shown in FIG. 8A, after forming wirings such as data lines and scanning lines and TFTs on the TFT array substrate 10 (not shown in FIG. 8), an interlayer insulating film 12 is laminated by CVD or the like. Here, a convex step 12a is formed on the surface of the interlayer insulating film 12 so as to correspond to the non-opening region of the image display region. For example, the convex step 12 a may be patterned after an interlayer insulating film is first formed flat on the TFT array substrate 10. Alternatively, it may be formed by further laminating an insulating film on an interlayer insulating film formed flat. In FIG. 8A, the rising angle of the convex step 12a formed on the interlayer insulating film 12 is formed at a right angle. However, it may be formed at an angle between 0 ° C. and 90 ° C. . That is, a forward taper of a desired angle may be given.

  Since the convex step 12a on the surface of the interlayer insulating film 12 defines the boundary region of the pixel electrode 9 disposed for each pixel, the non-opening region of the image display region, that is, the direction along the data line and the scanning line In addition, it may be provided in a lattice shape (see FIG. 4).

  Subsequently, as illustrated in FIG. 8B, a conductive material for patterning the pixel electrode 9 is formed in a solid shape on the interlayer insulating film 12. Specifically, a conductive material is formed on the interlayer insulating film by sputtering, CVD, or the like. Since the convex step 12a is already formed on the surface of the interlayer insulating film 12, a step is also generated on the surface of the conductive material formed in a solid shape accordingly.

  Note that the gradient of the step on the surface of the formed conductive material need not be the same as the gradient of the convex step 12 a on the surface of the interlayer insulating film 12. As a conductive material for patterning the pixel electrode 9, a transparent conductive material such as ITO (Indium Tin Oxide) may be used.

  In FIG. 8C, a resist film 16 is applied on the conductive layer for patterning on the pixel electrode 9 formed in a solid shape. In this embodiment, in particular, the resist film 16 is applied so as to have a flat surface by a technique such as spin coating. When the resist film is applied in this manner, the surface of the conductive layer for patterning on the pixel electrode 9 is formed with a level difference caused by the level difference on the surface of the interlayer insulating film 12, so that the surface of the conductive layer is raised. In the applied region, the resist film to be applied is formed thin. On the other hand, in the region where the surface of the conductive layer is recessed, the resist film is formed thick. Due to the resist film formed in this way, the region where the resist film is thinly formed is more sensitive than the region where the resist film is thickly formed. That is, the region where the resist film is thin is more sensitive than the region where the resist film is thick. Therefore, the surface of the underlying convex structure can be easily exposed by performing exposure. Furthermore, because of the surface free energy, the resist space structure for dividing the conductive layer into a plurality of island-shaped electrodes opened by the exposure and development process is attracted to the underlying convex structure. Therefore, the surface of the conductive layer having the base convex structure to be processed by etching can be accurately exposed as shown in FIG.

  Subsequently, in FIG. 9E, the conductive layer formed into a solid shape by etching the conductive layer from the resist film 16 that exposes the raised portion of the conductive layer with high accuracy. Divide into pixel electrodes 9. Here, as described above, the resist film 16 corresponding to the convex step 12a formed in the interlayer insulating film 12 is accurately exposed so that the raised portion of the conductive layer is exposed in the region by dry etching or the like. By removing the conductive layer, the solid conductive layer can be easily patterned into the plurality of pixel electrodes 9.

  When patterning the solid conductive layer, the resist film 16 and the conductive layer are removed so that the surface of the convex step 12a formed on the surface of the interlayer insulating film 12 is exposed. Further, it is desirable to remove an unnecessary conductive layer so that the pixel electrode 9 is in contact with the side wall portion 12 ′ of the step of the interlayer insulating film 12, but the side wall portion 12 ′ of the step of the interlayer insulating film 12 and the pixel electrode 9 If the gap is small enough, there is no problem even if it is not touching. More specifically, the etching back by wet etching or dry etching controlled by time or controlled by an etching stopper is performed until the surface of the convex step 12a is exposed.

  By removing the unnecessary conductive layer in this way, the step between the upper side portion of the convex step 12a on the surface of the interlayer insulating film 12 and the surface of the pixel electrode 9 formed in the vicinity thereof is reduced. A pixel electrode 9 can be formed.

  When the resist film 16 and the unnecessary conductive layer are removed, a part of the resist film 16 remains on the pixel electrode 9 formed as shown in FIG. 9E, and as shown in FIG. The resist film 16 is removed to complete the pixel electrode 9.

  Subsequently, as shown in FIG. 9G, a passivation film 14 is formed on the pixel electrode 9 and the interlayer insulating film 12 by, for example, CVD sputtering, spin coating, or the like. By providing the passivation film 14 in this manner, the step between the upper side portion of the convex step 12a on the surface of the interlayer insulating film 12 and the surface of the pixel electrode 9 formed in the vicinity thereof can be flattened. In other words, as described above, since the step between the upper side portion of the convex step 12a on the surface of the interlayer insulating film 12 and the surface of the pixel electrode 9 formed in the vicinity thereof is formed small, the passivation film 14 is temporarily provided. Although it is possible to form an alignment film with few defects on the upper layer side without forming a film, the number of defects is reduced on the upper layer side by reducing the level difference with the passivation film, and a good alignment film can be formed. Can be provided.

  Then, as shown in FIG. 9H, an alignment film 15 is formed on the passivation film 14 by, for example, spin coating, inorganic vapor deposition, or the like. As described above, the upper surface of the passivation film 14 formed on the lower layer side is formed relatively flat without a large step. Therefore, in the alignment film 15 formed on the passivation film 14, the number of defects caused by the step on the lower layer side is remarkably suppressed. Note that the surface of the alignment film 15 that is in contact with the liquid crystal 50 is formed to be flat and subjected to a rubbing process. At the time of this rubbing, the surface of the alignment film 15 is flattened very well, so that rubbing spots hardly occur and the generation and accumulation of rubbing residue can be reduced.

  In this way, a laminated structure such as the pixel electrode 9 can be completed on the TFT array substrate 10. The liquid crystal device according to the first embodiment can be manufactured by sandwiching the liquid crystal with the counter substrate on which the counter electrode and the alignment film are formed.

  Note that, in the liquid crystal device according to the second embodiment, when removing a part of the conductive layer formed on the interlayer insulating film 12 in FIG. Can be produced by removing the conductive layer.

  In the liquid crystal device manufactured by the above manufacturing method, the convex step 12a formed on the surface of the interlayer insulating film 12 exists between the adjacent pixel electrodes 9, and the upper layer side thereof is planarized by the passivation film 14. Therefore, even if the alignment film 15 is laminated, the number of defects generated in the alignment film 15 is remarkably small. As a result, it is possible to manufacture a liquid crystal device capable of displaying a high-quality image with less alignment disorder of alignment molecules in the liquid crystal.

<3: Electronic equipment>
Next, a specific example of an electronic apparatus to which the electro-optical device 100 according to this embodiment can be applied will be described with reference to FIG.

  First, an example in which the liquid crystal device 100 according to the present embodiment is applied to a display unit of a portable personal computer (so-called notebook personal computer) will be described. FIG. 10A is a perspective view showing the configuration of this personal computer. As shown in the figure, the personal computer 710 includes a main body 712 having a keyboard 711 and a display 713 to which the liquid crystal device 100 according to the present embodiment is applied as a panel.

  The liquid crystal device 100 according to the present embodiment is particularly preferably applied to a liquid crystal television or a display unit of a car navigation device. For example, by using the liquid crystal device 100 according to the present embodiment in the display unit of the car navigation device, a map image is displayed for an observer in the driver's seat, and an observer in the passenger seat is displayed. It is possible to display images such as movies.

  Next, an example in which the liquid crystal device 100 according to the present embodiment is applied to a display unit of a mobile phone will be described. FIG. 10B is a perspective view showing the configuration of this mobile phone. As shown in the figure, the mobile phone 720 includes a plurality of operation buttons 721, a receiver 722, a transmitter 723, and a display unit 724 to which the liquid crystal device 100 according to the present embodiment is applied.

  In addition to the personal computer shown in FIG. 10A and the mobile phone shown in FIG. 10B, electronic devices to which the liquid crystal device 100 according to this embodiment can be applied include a liquid crystal television and a viewfinder. Type / monitor direct-view type video tape recorder, car navigation device, pager, electronic notebook, calculator, word processor, workstation, videophone, POS terminal, digital still camera, etc.

  The above-described electro-optical device substrate and the electro-optical device are not limited to the above-described examples, and various changes can be made without departing from the scope of the present invention. .

  In the embodiments described above, the liquid crystal display panel is exemplified, but the electro-optical device of the present invention is similarly applied to an electrophoretic device such as electronic paper, and further to an EL (electroluminescence) device. It is possible.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. For electro-optical devices with such changes The substrate, the electro-optical device, and the electronic apparatus including the electro-optical device are also included in the technical scope of the present invention.

1 is a plan view of a liquid crystal device according to a first embodiment. It is HH 'sectional drawing of FIG. 1 is a block diagram illustrating an electrical configuration of a liquid crystal device according to a first embodiment. FIG. 2 is a perspective view showing a convex step on an interlayer insulating film formed in a lattice shape together with a pixel electrode in the first embodiment. It is sectional drawing which shows the orientation state of the liquid crystal molecule between the board | substrates in the image display area of the liquid crystal device which concerns on 1st Embodiment. It is sectional drawing which shows the orientation state of the liquid crystal molecule between the board | substrates in the image display area of a typical liquid crystal device. It is sectional drawing which shows the orientation state of the liquid crystal molecule between the board | substrates in the image display area of the liquid crystal device which concerns on 2nd Embodiment. It is process sectional drawing which shows the manufacturing method of the opposing board | substrate of the liquid crystal device which concerns on 1st Embodiment later on. It is process sectional drawing which shows the manufacturing method of the opposing board | substrate of the liquid crystal device which concerns on 1st Embodiment later on. It is a top view which shows the structure of the electronic device to which the electro-optical apparatus is applied.

Explanation of symbols

  6 data lines, 9 pixel electrodes, 10 TFT array substrate, 10a image display area, 11 scanning lines, 12 interlayer insulation film, 12a convex step, 14 passivation film, 16 resist film, 20 counter substrate, 21 counter electrode, 23 Black matrix, 30 TFT, 50 liquid crystal

Claims (11)

A method of manufacturing an electro-optical device in which an electro-optical material is sandwiched between a pair of substrates,
A first step of forming an insulating film having a convex step on one of the pair of substrates so as to extend in at least one of a first direction and a second direction intersecting with each other;
A second step of forming a solid conductive layer on the insulating film so as to have a step corresponding to the convex step on the surface;
And a third step of dividing the conductive layer into a plurality of island-shaped electrodes by patterning the conductive layer so that the convex steps are exposed. The third step includes
A resist film forming step of forming a resist film on the conductive layer;
An etching step of removing the conductive layer by etching so that the convex step is exposed when viewed in plan on the substrate;
The method for manufacturing an electro-optical device according to claim 1, further comprising: a resist film removing step of removing a resist film remaining on the electrode.   The method according to claim 1, further comprising a fourth step of forming an operation regulating film that regulates an operation state of the electro-optic material on the plurality of island-shaped electrodes and the convex steps. Manufacturing method of the electro-optical device.   4. The method of manufacturing an electro-optical device according to claim 3, further comprising a step of forming a passivation film on the plurality of island-shaped electrodes and the convex steps before the fourth step. .   5. The electro-optical device according to claim 1, wherein the convex steps are formed in a lattice shape along the first direction and the second direction. 6. Production method.   The said 3rd process WHEREIN: The said conductive layer is patterned so that the side surface of the said conductive layer may contact | connect the surface of the side wall of the said convex-shaped level | step difference, The Claim 1 characterized by the above-mentioned. Manufacturing method of electro-optical device. A pair of substrates sandwiching the electro-optic material;
An insulating film formed on one of the pair of substrates and having a convex step so as to extend in at least one of a first direction and a second direction intersecting each other;
An electro-optical device comprising: a plurality of island-shaped electrodes formed on the insulating film and divided from each other by the convex steps.   The electro-optical device according to claim 6, further comprising an operation restricting film that is formed on the plurality of island-shaped electrodes and the convex step and restricts an operation state of the electro-optical material. .   The electro-optical device according to claim 8, further comprising a passivation film stacked on the plurality of island-shaped electrodes and the convex step and below the operation restriction film.   9. The electro-optical device according to claim 6, wherein the plurality of island-shaped electrodes are formed so that side surfaces thereof are in contact with a surface of a side wall of the convex step.   An electronic apparatus comprising the electro-optical device according to claim 7.

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