JP2005251845A - Method for manufacturing nonlinear element, nonlinear element, electrooptical device, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a nonlinear element by reducing weight by using a plastic substrate and preventing deformation in the substrate in processing. <P>SOLUTION: When forming the nonlinear element (for example TFD 13) on the flexible plastic substrate 10, first a wiring film 141 for energization for anode oxidization is formed in a line on the plastic substrate 10 by using a mask sputtering method and a droplet discharge method. In this case, as a material of the wiring film 141, a material that can be subjected to anode oxidization and has small film stress, such as a conductive material containing a valve metal such as aluminum, is used. Then, a plurality of electrode films 142 that form the body of the lower electrode of TFD 13 are formed along the line on the surface of the wiring film 141, by using the mask sputtering method and the droplet discharge method. Then, the surface of each electrode film 142 is subjected to anode oxidization collectively by using the wiring film 141, and an upper electrode 11 in the TFD 13 is formed on the surface of an obtained anode oxide film 18. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a nonlinear element, a nonlinear element, an electro-optical device, and an electronic apparatus.

As a pixel switching element of an active matrix liquid crystal device or the like, a non-linear element having a laminated structure (MIM structure) of first conductive film / insulating film / second conductive film, for example, a TFD (Thin Film Diode) is known. ing. In general, a glass substrate or a quartz substrate is used for this type of liquid crystal device. However, in recent years, it has been studied to use a plastic substrate as the substrate for the purpose of reducing the weight (for example, see Patent Document 1).
JP-A-8-212399

As described in Patent Document 1, a plastic substrate that can be formed by a roll-to-roll technique is greatly expected from the viewpoint of productivity in addition to its light weight and high fracture toughness. However, if the entire surface of an inorganic / metal film is sputtered onto an organic base material such as plastic, the substrate will be deformed even if the film is formed at room temperature for a material having a large film stress during the film formation. For this reason, sufficient accuracy cannot be obtained when etching a metal film or the like formed on the entire surface of the substrate. As a countermeasure, for example, Japanese Patent Application Laid-Open No. 2001-279011 proposes a method using a reinforcing plate to suppress substrate deformation, but this is a device for preventing substrate deformation during the process. Thus, the substrate is warped when it is removed from the reinforcing plate.
In view of this, Japanese Patent Laid-Open No. 2003-101193 proposes a method in which the amount of deformation of the substrate after film formation is estimated in advance and the substrate is deformed in the reverse direction in advance. However, this method requires a new deformation amount estimation when various process conditions and film configurations change, and there are problems with the calculation results and the processing accuracy of the prior deformation.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for manufacturing a nonlinear element capable of preventing substrate deformation during a process while reducing the weight using a plastic substrate. .

In order to solve the above-described problems, a method for manufacturing a nonlinear element according to the present invention includes a nonlinear element formed by sequentially laminating a first conductive film, an insulating film, and a second conductive film on a flexible plastic substrate. In the manufacturing method, the first conductive film is formed in a region where an element is to be formed by using a method in which a material film can be selectively deposited only in a predetermined region. And a step of selectively depositing it.
Specifically, the step of forming the first conductive film can be performed by a mask sputtering method or a droplet discharge method.
In this method, in order to suppress the warpage of the substrate that has conventionally been caused by performing the entire surface sputtering, the first conductive film serving as the lower electrode of the nonlinear element is divided into the element formation region by mask sputtering or the like. It is intended to be deposited in a state. That is, in the conventional process of forming the lower electrode, a metal material such as tantalum is sputtered on the entire surface of the substrate, and this is patterned by etching. For this reason, when the entire surface of the metal is sputtered, the plastic substrate is greatly warped with the film formation surface convex, and the subsequent handling of the substrate is difficult. On the other hand, in the present invention, since the first conductive film is formed in a state of being divided from the beginning without being sputtered entirely, the substrate is not warped at least in the dividing direction. Therefore, when this method is used, the amount of deformation of the substrate is remarkably reduced as compared with the conventional one in which the warpage in the two directions of left, right, up and down is combined.

  In the nonlinear element manufacturing method of the present invention, the first conductive film is made of a conductive material including a valve metal, and the insulating film forming step includes anodizing the first conductive film to form the first conductive film. A step of forming an insulating film on the surface of the conductive film can be included. By using the anodic oxidation method in this way, a high-quality insulating film can be formed.

In this method, the step of forming the first conductive film includes a step of forming a wiring film for anodic oxidation in a line shape, and an island-shaped electrode film including the valve metal on the surface of the wiring film. And a step of electrically insulating each electrode film by removing the wiring film located between the adjacent electrode films after the formation of the insulating film. . This makes it possible to collectively form a plurality of nonlinear elements that are electrically insulated from each other.
In this case, it is preferable that the wiring film is made of a material having a smaller film stress than the electrode film. By doing so, the amount of deformation of the substrate can be reduced as compared with the conventional case where the first conductive film is a single layer film of tantalum metal or the like.

  In this method, the wiring film forming step may include a step of forming the outermost surface of the wiring film with a first conductive material made of a valve metal. By doing so, the surface of the electrode film can be efficiently anodized during energization. That is, when the wiring film does not contain a valve metal, that is, when the wiring film is made of a material that is not anodized, current is passed through the wiring film, and the electric field necessary for forming the anodized film on the surface of the electrode film Will not occur. On the other hand, since the surface of the wiring film is also anodized in this method, an effective electric field is generated in the electrode film as compared with the above case, and the insulating film can be formed more efficiently.

In this method, it is preferable that the first conductive material is made of a material having a film stress smaller than that of the electrode film. By doing so, the warpage of the substrate can be reduced. As the first conductive material, aluminum having the smallest film stress among the valve metals is suitable.
Further, in this method, the wiring film forming step may include forming a layer on the lower layer side of the layer made of the first conductive material of the wiring film with a second conductive material having a smaller film stress than the electrode film, for example, gold , Silver, copper, aluminum, or a conductive organic material. By so doing, substrate deformation can be further reduced.

The nonlinear element of the present invention is a nonlinear element formed by sequentially laminating a first conductive film, an insulating film, and a second conductive film on a flexible plastic substrate, and the first conductive film comprises: It is characterized by comprising a multilayer film including a layer made of a first conductive material that is a valve metal and a layer made of a second conductive material having a film stress smaller than that of the first conductive material.
In this way, by forming the first conductive film as a multilayer film, a film that can be anodized and has a small film stress can be obtained. For this reason, compared with the conventional case where the first conductive film is a single-layer film made of tantalum metal or the like, the warpage of the substrate during the process is reduced, and the element can be miniaturized and the quality can be improved.

  The electro-optical device according to the present invention includes a nonlinear element manufactured by the above-described method. According to another aspect of the invention, an electronic apparatus includes the electro-optical device. Thereby, a high-definition and high-contrast electro-optical device and electronic apparatus can be provided.

[First Embodiment]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
(Configuration of liquid crystal device)
FIG. 1 is a block diagram showing an electrical configuration of a liquid crystal device which is an example of an electro-optical device according to the invention. The liquid crystal device shown in the figure is an active matrix liquid crystal device using a TFD (Thin Film Diode) element (two-terminal nonlinear element) as a switching element. The liquid crystal device includes a plurality of scanning lines 25 extending in the X direction, a plurality of data lines 11 extending in the Y direction, and subpixels 50 provided at each intersection of the scanning lines 25 and the data lines 11. Have Further, among the plurality of scanning lines 25, the odd-numbered scanning lines 25 counted from the top in FIG. 1 (hereinafter simply referred to as “odd-numbered scanning lines”) are connected to the first Y driver IC 401, The even-numbered scanning lines 25 (hereinafter simply referred to as “even-numbered scanning lines”) counted from the top in FIG. 1 are connected to the second Y driver IC 402. The scanning signal generated by these Y driver ICs is supplied to each scanning line 25.

  Hereinafter, the first Y driver IC 401 and the second Y driver IC 402 are simply referred to as “Y driver IC 40” when it is not necessary to distinguish between them. Each data line 11 is connected to an X driver IC 41, and a data signal generated by the X driver IC 41 is supplied. On the other hand, each of the plurality of sub-pixels 50 arranged in a matrix corresponds to one of R (red), G (green), and B (blue). Each sub-pixel 50 has a configuration in which a liquid crystal display element 51 and a TFD element 13 are connected in series.

Next, FIG. 2 is a perspective view showing a configuration when the liquid crystal device according to the present embodiment is viewed from the back side (that is, the side opposite to the side where the observer should be positioned). As shown in FIG. 2, the negative direction of the X axis is defined as “A side” and the positive direction is defined as “B side”.
As shown in FIG. 2, in the liquid crystal device, an element substrate (support substrate) 10 and a counter substrate (other substrate) 20 that face each other are bonded together by a sealing material 30 and surrounded by both the substrates and the sealing material 30. A liquid crystal (not shown in FIG. 2), which is an electro-optical material, is sealed in the region. The sealing material 30 is formed in a substantially rectangular frame shape along the edge of the counter substrate 20, but has a shape in which a part is opened to enclose the liquid crystal. For this reason, the opening is sealed with the sealing material 31 after the liquid crystal is sealed.

  The sealing material 30 has a large number of conductive particles dispersed therein. The conductive particles are, for example, plastic particles plated with metal or conductive resin particles. The conductive particles are electrically connected to each other on the element substrate 10 and the counter substrate 20. It also functions as a spacer that keeps the gap (cell gap) between the substrates constant. Actually, a polarizing plate for polarizing incident light, a retardation plate for compensating for interference colors, and the like are appropriately attached to the outer surfaces of the element substrate 10 and the counter substrate 20.

  The element substrate 10 and the counter substrate 20 are flexible plastic film base materials having optical transparency such as polyethylene terephthalate (PET) and polycarbonate (PC). Among these, the plurality of data lines 11 described above are formed on the inner surface (opposite substrate 20 side) surface of the element substrate 10 located on the observation side, while the inner side (element substrate 10 side) of the counter substrate 20 located on the back side. A plurality of scanning lines 25 are formed on the surface. In addition, the element substrate 10 has an area outside the sealing material 30 (that is, an area that does not face the sealing material 30 and the liquid crystal; hereinafter, referred to as an “edge area”) 10 a. An X driver IC 41 is mounted near the center of the edge region 10a in the X direction, and a first Y driver IC 401 and a second Y driver IC 402 are mounted at positions on both sides of the X driver IC 41. . That is, these driver ICs are mounted on the element substrate 10 via an anisotropic conductive film (ACF) in which conductive particles are dispersed in an adhesive. Further, a plurality of pads 17 are formed in the vicinity of the edge of the element substrate 10 in the edge region 10a, and one end of a flexible substrate (not shown) is bonded in the vicinity of the portion where the pads 17 are formed. Is done. An external device such as a circuit board is joined to the other end of the flexible board.

  Under such a configuration, the X driver IC 41 generates a data signal according to a signal input from an external device via the flexible substrate and the pad 17, and outputs the data signal to the data line 11. On the other hand, the Y driver ICs 401 and 402 generate and output a scanning signal in accordance with a signal input from an external device via the flexible substrate and the pad 17. This scanning signal is transmitted from the routing wiring 16 formed on the element substrate 10 to the counter substrate 20 side through the conductive particles in the sealing material 30, and is applied to each scanning line 25 on the upper substrate 20.

  Next, a configuration of a region (hereinafter referred to as “display region”) surrounded by the inner peripheral edge of the sealing material 30 in the liquid crystal device will be described. FIG. 3 is a diagram showing a portion in the display area of the cross section taken along line C-C ′ in FIG. 2. 4A is a plan configuration diagram showing one sub-pixel region of the liquid crystal device according to the present embodiment, and FIG. 4B is an enlarged view of the TFD element 13 shown in FIG. FIG. 4C is a cross-sectional configuration diagram taken along the line DD ′ shown in FIG. 4B.

  As shown in FIG. 3, the liquid crystal device according to the present embodiment is sealed in a region sandwiched between the element substrate 10 and the counter substrate 20 that are arranged to face each other and the substrates 10 and 20. The liquid crystal 35 is provided. A plurality of pixel electrodes 12 arranged in a matrix and a plurality of pixel electrodes 12 extending in the Y direction on the inner surface (on the liquid crystal 35 side) surface of the element substrate 10 in the display region shown in FIG. Data lines 11 are formed. Each pixel electrode 12 is a substantially rectangular electrode in plan view formed of a transparent conductive material such as ITO (Indium Tin Oxide). Each pixel electrode 12 and the data line 11 adjacent to the pixel electrode 12 on one side are connected via a TFD element (nonlinear element) (not shown) (see FIG. 4A). Further, as shown in FIG. 3, the surface of the element substrate 10 on which the data lines 11, the pixel electrodes 12, and the TFD elements are formed is covered with an alignment film 151. The alignment film 151 is an organic thin film made of polyimide or the like, and is subjected to a rubbing process for defining the alignment direction of the liquid crystal 35 when no voltage is applied.

  Here, as shown in FIG. 4A, when a region corresponding to one sub pixel 50 among the elements on the element substrate 10 is viewed from the counter substrate 20 side (back side), the pixel having a substantially rectangular shape in a plan view. A data line 11 is formed so as to extend along the long side direction of the electrode 12. As shown in the enlarged plan view of FIG. 4B, the TFD element 13 includes a rectangular lower electrode (first conductive film) 14 extending substantially parallel to the data line 11 and the lower electrode. The first insulating film 18 formed on the surface 14 by anodic oxidation, the first upper electrode (second conductive film) 11a formed on the insulating film 18 and spaced apart from each other, and the second upper electrode ( Second conductive film) 19. As shown in FIG. 4A, the first upper electrode 11a is formed by extending a part of the data line 11 toward the pixel electrode 12, and the second upper electrode 19 is formed by the lower electrode. The TFD element 13 and the pixel electrode 12 are electrically connected so as to partially overlap the pixel electrode 12 at the end opposite to the pixel 14.

  The TFD element 13 includes a first TFD element 131 and a second TFD element 132. That is, in the planar region of the lower electrode 14, the first TFD element 131 is formed in a region facing the first upper electrode 11 a via the insulating film 18, and the second upper electrode 14 is interposed via the insulating film 18. A second TFD element 132 is formed in a region facing the electrode 19.

The second TFD element 132 will be described in more detail. As shown in FIG. 4C, the base insulating film 4 formed on the element substrate 10 and the lower electrode provided on the base insulating film 4 14 and an insulating film 18 covering the surface of the lower electrode 14. And, as a result of adopting a metal / insulator / metal sandwich structure in a region where the second upper electrode 19 and the lower electrode 14 face each other through the insulating film 18, it has a positive and negative bidirectional diode switching characteristic. A TFD element 132 is configured.
Although not shown, the first TFD element 131 has a configuration in which the first upper electrode 11a is arranged in place of the upper electrode 19 in the cross-sectional structure shown in FIG.

In the TFD element 13 according to the present embodiment, the first TFD element 131 and the second TFD element 132 are formed on the lower electrode 14 so as to be separated from each other. Has opposite diode switching characteristics. Thus, since the TFD element 13 has a configuration in which two diodes are connected in series in opposite directions, the current-voltage nonlinear characteristic is bi-directional with positive and negative in comparison with the case where one diode is used. Symmetrized over.
However, in order to ensure the symmetry of such nonlinear characteristics, the thickness of the insulating film 18 constituting the first TFD element 131 and the thickness of the insulating film 18 constituting the second TFD element 132 are the same. In addition, the areas of the upper electrodes 11a and 19 in a region facing the lower electrode 14 through the insulating film 18 must be made equal. In the present embodiment, as shown in FIG. 4B, the insulating film 18 is formed so as to cover the lower electrode 14, and therefore, if the upper electrodes 11a and 19 are formed to have the same width, the TFD element 131, 132 symmetry can be easily obtained.

In the present embodiment, the lower electrode 14 has a multilayer structure including a conductive layer 141 and a conductive layer 142. The conductive layer 142 is made of a conductive material including a valve metal. Here, the valve metal (valve metal) is a metal whose surface is uniformly covered with an oxide film of the metal by anodic oxidation (that is, oxygen vacancies in the oxide formed on the metal surface move). Examples of the valve metal include aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), niobium (Nb), and tantalum (Ta). In the present embodiment, the conductive layer 142 is made of, for example, tantalum (Ta) alone or an alloy containing tantalum as a main component. The conductive layer 141 on the lower layer side of the conductive layer 142 is made of a conductive material containing a valve metal whose film stress is smaller than that of the conductive material constituting the conductive layer 142, for example, aluminum. The data line 11 (including the first upper electrode 11a) and the second upper electrode 19 are formed of the same layer made of various conductive materials such as chrome (Cr) and aluminum (Al), for example, In addition to a metal material, tantalum or molybdenum (Mo) can be used.
Further, the base insulating film 4 provided on the lower side of the lower electrode 14 can be formed of, for example, tantalum oxide or the like, and the lower electrode 14 can function as an adhesion layer for fixing the substrate 10.

On the other hand, as shown in FIG. 3, a reflective layer 21, a color filter 22, a light shielding layer 23, an overcoat layer 24, a plurality of scanning lines 25 and an alignment film 26 are formed on the surface of the counter substrate 20.
The reflective layer 21 is a thin film formed of a metal having light reflectivity such as aluminum or silver. Light incident on the liquid crystal device from the observation side is reflected on the surface of the reflection layer 21 and emitted to the observation side, thereby realizing a so-called reflection type display. Here, as shown in FIG. 3, the region covered with the reflective layer 21 on the inner surface of the counter substrate 20 is a rough surface on which a large number of fine irregularities are formed. Therefore, fine irregularities (that is, scattering structures) reflecting the rough surface are formed on the surface of the reflective layer 21 formed in a thin film so as to cover the rough surface. As a result, incident light from the observation side is reflected in a state of being appropriately scattered on the surface of the reflective layer 21, and a specular reflection on the surface of the reflective layer 21 is avoided to realize a wide viewing angle. Further, if an opening region where the reflective layer 21 is not partially formed is provided in the planar region of the pixel electrode 12 shown in FIG. 4A, transmissive display through the opening region becomes possible, and transflective Type liquid crystal device can be constructed.
Note that FIG. 3 illustrates a case where the uneven shape is directly formed on the surface of the substrate 20, but the structure for imparting the scattering function to the reflective layer 21 is not limited to the example given in this embodiment. For example, a resin film is formed on the substrate 20 and irregularities are formed on the surface thereof, or an optical element having light scattering properties on the reflective layer 21 (a resin film obtained by kneading and curing materials having different refractive indexes) Of course, it is also possible to apply the one provided with.

The color filter 22 is a resin layer formed on the surface of the reflective layer 21 corresponding to each sub-pixel 50, and any of R (red), G (green), and B (blue) depending on the dye or pigment. It is colored crab. A pixel (dot) of the display image is configured by the three sub-pixels 50 corresponding to different colors. The light shielding layer 23 is formed in a lattice shape corresponding to the gaps between the pixel electrodes 12 arranged in a matrix on the element substrate 10, and plays a role of shielding the gaps between the pixel electrodes 12.
As shown in FIG. 3, the light shielding layer 23 in the present embodiment has a configuration in which color filters 22 for three colors of R, G, and B are laminated. The overcoat layer 24 is a layer for flattening the unevenness formed by the color filter 22 and the light shielding layer 23, and is formed of, for example, an epoxy or acrylic resin material.

The scanning line 25 is a belt-like electrode formed on the surface of the overcoat layer 24 by a transparent conductive material such as ITO. Each scanning line 25 is formed to extend in the X direction in the figure so as to face the plurality of pixel electrodes 12 that are arranged in the X direction on the element substrate 10. Then, the liquid crystal display element 51 shown in FIG. 1 is configured by the pixel electrode 12, the scanning line 25 opposed to the pixel electrode 12, and the liquid crystal 35 sandwiched therebetween.
That is, when a voltage higher than the threshold is applied to the TFD element 13 by supplying a scanning signal to the scanning line 25 and supplying a data signal to the data line 11, the TFD element 13 is turned on. As a result, charges are accumulated in the liquid crystal display element 51 connected to the TFD element 13, and the alignment direction of the liquid crystal 35 changes. Thus, the desired display is performed by changing the orientation direction of the liquid crystal 35 for each sub-pixel 50. On the other hand, even if the TFD element 13 is turned off after the charge is accumulated, the charge accumulation in the liquid crystal display element 51 is maintained. Further, the surface of the overcoat layer 24 on which the plurality of scanning lines 25 are formed is covered with an alignment film 26 similar to the alignment film 151 on the element substrate 10.

  The liquid crystal device of the present embodiment having the above-described configuration includes the nonlinear element TFD13 according to the present invention that can be manufactured by a manufacturing method described later, and the plurality of TFD elements 13 provided as the pixel switching elements are uniform. It is formed with device characteristics. Accordingly, the display characteristics of the sub-pixel 50 are uniform, and a high-quality display can be obtained.

(Method for manufacturing element substrate)
Next, a method for manufacturing a nonlinear element according to the present invention and a method for manufacturing the liquid crystal device according to the previous embodiment including the nonlinear element will be described with reference to FIG. FIG. 5 is a process diagram for explaining the manufacturing method of the nonlinear element according to the present embodiment, and is a schematic plan view showing an enlarged part of the planar structure of the element substrate.

  First, as shown in FIG. 5A, a plastic support substrate 10 such as polyethylene terephthalate (PET) or polycarbonate (PC) is prepared. The support substrate 10 should form the element substrate 10 shown in FIGS. 2 to 4 through the respective steps according to the present embodiment. A base insulating film 4 (see FIG. 4C) made of tantalum oxide or the like is formed on the surface of the support substrate 10 as necessary.

  Next, a plurality of conductive layers 141 are formed in a line shape on the support substrate using a method such as a mask sputtering method. The conductive layer 141 functions as a wiring film for energization when the surface of a conductive layer 142 described later is anodized. In the present embodiment, the conductive layer 141 is formed of a valve metal having a film stress smaller than that of the conductive layer 142, such as aluminum, and has a thickness of 50 nm, for example. In this embodiment, since the conductive layer 141 is patterned by mask sputtering, a lower electrode metal such as tantalum is formed on the entire surface of the substrate as in the prior art, and the deformation of the substrate 10 is compared to the case where this is patterned by etching. The amount can be reduced. That is, when a metal film is formed on the substrate 10, the substrate 10 after film formation is greatly warped with the film formation surface as a convex surface due to the difference in thermal expansion coefficient between the metal and the substrate 10 made of plastic. On the other hand, when the metal is formed in a line shape as in this embodiment, the substrate 10 is not stressed in the Y direction, which is the direction in which the conductive layer 141 is divided. Less. In this embodiment, since the conductive layer 141 is formed of a material having a smaller film stress than that of the conductive layer 142 which is the main body of the lower electrode 14, the lower electrode 14 is formed of a single layer of tantalum as in the prior art. Compared to the case, the stress in the X direction, which is the extending direction of the conductive layer 141, is also reduced.

Next, as shown in FIG. 5B, an island-shaped conductive layer serving as the main body of the lower electrode 14 is formed on the surface of each conductive layer 141 formed in a line shape using a method such as mask sputtering. A plurality of (electrode films) 142 are formed along the line. Since the surface of the conductive layer 142 is anodized in a process described later, a conductive material that can be anodized, that is, a conductive material including a valve metal is used as the conductive layer 142. In the present embodiment, the conductive layer 142 is formed of tantalum alone or an alloy containing tantalum as a main component, and has a film thickness of, for example, 100 nm. In this embodiment, since the conductive layer 142 is formed in a state of being divided in both the X direction and the Y direction, the substrate 10 is not warped by the formation of the conductive layer 142.
In this example, the conductive layers 141 and 142 are formed by mask sputtering. However, the method of forming the conductive layers is not limited to this, and the conductive material is selectively placed at a predetermined position on the substrate without depending on subsequent processes such as etching. Any method that can be deposited is acceptable. For example, a liquid material containing a conductive material may be selectively discharged onto a substrate by a droplet discharge method and dried or baked.

  Next, as shown in FIG. 5C, the surface of the upper conductive layer 142 is anodized using the conductive layer 141 which is a wiring film, and an anodic oxide film (in this example) is formed on the surface of the conductive layer 142. In this case, an insulating film 18 made of tantalum oxide is formed. In this embodiment, since a valve metal is used for the conductive layer 141, an anodic oxide film 141a (in this example, aluminum oxide) is also formed on the surface of the conductive layer 141 by this process. For this reason, it is possible to efficiently anodize the conductive layer 142 without energizing only the portion of the conductive layer 141 unlike the case where the conductive layer 141 is made of another conductive material.

Next, as shown in FIG. 5D, the conductive layer 141 located between the adjacent conductive layers 142 and its oxide film 141a are removed by etching or the like, and each conductive layer 142 is electrically insulated. As described above, the lower electrode 14 (conductive layer 141 and conductive layer 142) and the insulating film 18 of each TFD element 13 are formed.
Subsequently, an upper electrode 19 made of chromium is formed so as to partially cover the insulating film 18 on the lower electrode 14 by using a method such as a mask sputtering method or a droplet discharge method. When the pattern of the upper electrode 19 is formed, the data line 11 (including the upper electrode 11a) shown in FIG. Thus, the TFD element 13 is obtained.

Next, as shown in FIG. 4A, the pixel electrode 12 made of a transparent conductive material such as ITO is formed so as to partially ride on one end side (the side opposite to the lower electrode 14) of the second upper electrode 19. If the alignment film 151 covering these constituent members is formed, the element substrate 10 shown in FIG. 2 is obtained.
Then, the element substrate 10 obtained through the manufacturing process according to the manufacturing method of the present embodiment is bonded to the counter substrate 20 separately manufactured by a known manufacturing method and the sealing material 30 as shown in FIG. In addition, the liquid crystal device of the previous embodiment is obtained by sealing the liquid crystal in a space between the sealing material 30 and the two substrates 10 and 20.

As described above, in this embodiment, since the conductive film constituting the TFD 13 is formed only in the element formation region by mask sputtering or the like, after the conductive film is formed over the entire surface of the substrate as in the prior art. The amount of deformation of the substrate 10 can be reduced compared to the case where this is patterned by etching or the like. In particular, in this embodiment, since the lower electrode 14 is a laminated film of the conductive layer 142 made of tantalum or the like and the conductive layer 142 having a film stress smaller than that of the conductive layer 142, the lower electrode 14 is made of tantalum alone as in the prior art. Compared with the case of forming, the deformation amount of the substrate is further reduced.
In the present embodiment, since a common wiring film (conductive layer 141) is formed for each conductive layer 142, and this wiring film 141 is cut after anodization, a plurality of TFDs that are electrically insulated from each other. Elements can be formed in a lump and the process becomes easy.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
FIG. 6 is a schematic diagram showing a cross-sectional structure of a TFD element that is an example of the nonlinear element of the present invention. In the present embodiment, the same members or parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
In this embodiment, in the configuration of the first embodiment, the conductive layer 141 of the lower electrode 14 which is a wiring film for anodic oxidation is configured by a plurality of layers. In other words, in the present embodiment, the conductive layer 141 of the TFD element 132 is divided into a layer 141b made of a valve metal (first conductive material) having a smaller film stress than the conductive layer 142 and a film stress higher than that of the first conductive material. A layered structure of layers 141b made of a small second conductive material is employed. As the first conductive material, for example, aluminum is suitable, and as the second conductive material, for example, a metal material of gold, silver, copper, or aluminum or a conductive organic material is suitable.
The rest is the same as in the first embodiment.

  In this embodiment, the layer 141a on the lower layer side of the conductive layer 141 is made of a soft material (small film stress) such as a conductive organic material. Therefore, the conductive layer 141 is made of aluminum as in the first embodiment. Compared with a single layer film such as the above, the stress during film formation is reduced, and the warpage of the substrate can be further reduced. Further, since the outermost layer 141b of the conductive layer 141 is made of an anodizable metal, the surface of the conductive layer 142 is not energized only in the wiring portion (portion other than the conductive layer 142) during anodization. It is possible to oxidize efficiently.

(Electronics)
Next, the electronic apparatus of the present invention will be described.
FIG. 7 is a perspective configuration diagram illustrating an example in which the electro-optical device according to the invention is applied to a display unit of a mobile phone. As shown in the figure, a cellular phone 1300 includes the liquid crystal device (electro-optical device) of the above-described embodiment as a small-sized display unit 1301, and includes a plurality of operation buttons 1302, an earpiece 1303, and a mouthpiece 1304. Configured.
The liquid crystal device of the above embodiment is not limited to the mobile phone, but an electronic book, a personal computer, a digital still camera, a liquid crystal television, a viewfinder type or a monitor direct-view type video tape recorder, a car navigation device, a pager, an electronic notebook, It can be suitably used as an image display means for calculators, word processors, workstations, videophones, POS terminals, touch panel-equipped devices, etc. In any electronic device, it has high definition, high contrast, and uniform brightness. A high-quality display can be provided.

As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.
For example, in the above-described embodiment, the liquid crystal device is described as an example of the electro-optical device of the present invention, but the present invention can be applied to various electro-optical devices and manufacturing methods thereof that are not limited to the liquid crystal device. For example, it can be suitably used in EL (electroluminescence) devices, electrophoresis devices, devices using plasma emission or fluorescence by electron emission (for example, PDP, FED, SED), production methods thereof, and the like.

1 is a circuit block diagram of a liquid crystal device which is an example of an electro-optical device of the invention. The perspective block diagram which shows an external appearance similarly. FIG. 3 is a cross-sectional configuration diagram taken along line C-C ′ of FIG. 2. (A) is a plane block diagram of the pixel area | region of the liquid crystal device, (b) is an enlarged plan view of a TFD element, (c) is a cross-sectional block diagram along the D-D 'line of (b). Sectional process drawing for demonstrating the manufacturing method of the nonlinear element of this invention. Sectional drawing which shows the structure of the nonlinear element which concerns on 2nd Embodiment of this invention. FIG. 11 is a perspective configuration diagram illustrating an example of an electronic apparatus according to the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Element substrate, 13 ... TFD element (two-terminal nonlinear element), 14 ... Lower electrode (first conductive film), 141 ... Conductive layer (wiring film), 142 ... Conductive layer (electrode film) , 18 ... insulating film, 11a ... first upper electrode (second conductive film), 19 ... second upper electrode (second conductive film), 1300 ... electronic equipment

Claims (13)

A method of manufacturing a nonlinear element comprising a first conductive film, an insulating film, and a second conductive film on a plastic substrate having flexibility,
The first conductive film forming step selectively deposits the first conductive film on a region where an element is to be formed using a method capable of selectively depositing a material film only on a predetermined region. The manufacturing method of the nonlinear element characterized by including the process to make.   2. The method of manufacturing a nonlinear element according to claim 1, wherein the step of forming the first conductive film is performed by a mask sputtering method or a droplet discharge method.   The first conductive film is made of a conductive material containing a valve metal, and the insulating film forming step forms an insulating film on the surface of the first conductive film by anodizing the first conductive film. The method for manufacturing a nonlinear element according to claim 1, further comprising a step.   The step of forming the first conductive film includes a step of forming a wiring film for energization for anodization in a line shape, and an island-shaped electrode film including the valve metal on the surface of the wiring film in the line. And a step of electrically insulating each electrode film by removing the wiring film located between the adjacent electrode films after the formation of the insulating film. A method for manufacturing a nonlinear element according to claim 3.   The method of manufacturing a nonlinear element according to claim 4, wherein the wiring film is made of a material having a film stress smaller than that of the electrode film.   6. The method of manufacturing a nonlinear element according to claim 4, wherein the forming step of the wiring film includes a step of forming an outermost surface of the wiring film with a first conductive material made of a valve metal.   The method for manufacturing a nonlinear element according to claim 6, wherein the first conductive material is made of a material having a film stress smaller than that of the electrode film.   The method for manufacturing a nonlinear element according to claim 6, wherein the first conductive material is aluminum.   The step of forming the wiring film includes a step of forming a layer on the lower side of the layer made of the first conductive material of the wiring film with a second conductive material having a film stress smaller than that of the electrode film. The method for manufacturing a non-linear element according to claim 6, wherein the method is characterized in that:   The method for manufacturing a nonlinear element according to claim 9, wherein the second conductive material is a metal material or a conductive organic material of gold, silver, copper, or aluminum. A non-linear element comprising a first conductive film, an insulating film, and a second conductive film on a plastic substrate having flexibility,
The first conductive film is made of a multilayer film including a layer made of a first conductive material that is a valve metal and a layer made of a second conductive material having a film stress smaller than that of the first conductive material. A non-linear element characterized by the above.   An electro-optical device comprising a nonlinear element manufactured by the method according to claim 1.   An electronic apparatus comprising the electro-optical device according to claim 12.

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