JP2006203021A - Nonlinear element, electro-optical device, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-linear element in which element destruction does not occur even during continuous energization for a long time or application of a high electric field, an electro-optical device for driving a pixel electrode via the non-linear element, and an electronic apparatus equipped with the electro-optical device To provide.
In an active matrix electro-optical device, a nonlinear element 10 used as a pixel switching element includes a lower electrode 13 made of niobium or an alloy thereof, and an insulator 14 formed by anodizing the surface of the lower electrode 13. And an upper electrode 15 facing the lower electrode 13 with the insulator 14 interposed therebetween. Since the insulator 14 made of a niobium anodic oxide film has many defects, breakdown due to overcurrent is dispersed during continuous energization for a long time or application of a high electric field, so that element breakdown is unlikely to occur.
[Selection] Figure 1

Description

  The present invention relates to a non-linear element including an insulator between a pair of electrodes, an electro-optical device that drives a pixel electrode through the non-linear element, and an electronic apparatus including the electro-optical device.

As a pixel switching element, a liquid crystal device including a diode-type nonlinear element having a laminated structure of MIM (Metal-Insulator-Metal) for each pixel is commercially available. Conventionally, such an MIM type non-linear element includes a lower electrode made of a tantalum (Ta) layer, an insulator made of a tantalum oxide film formed by anodizing the surface of the lower electrode, and an upper electrode made of a chromium film or the like. Have a structure laminated in this order. In addition, a nonlinear element using a tantalum alloy to which tungsten (W), molybdenum (Mo), or the like is added as a lower electrode has been proposed (see, for example, Patent Document 1).
JP 7-261200 A

  However, a non-linear element using tantalum or the above tantalum alloy as a lower electrode and using an anodic oxide film of these metals as an insulator has an advantage that the leakage current is small. There is a drawback that element destruction is likely to occur when applying. Such element destruction is not preferable because it causes display point defects and burn-in in the liquid crystal device.

  On the other hand, as a technical field in which tantalum and tantalum oxide are used, there is a field of capacitors. In such a field of capacitors, it is considered to use niobium which is cheaper than tantalum instead of tantalum. However, it has been pointed out that when niobium is used, the leakage current is larger than when tantalum is used.

  Here, the applicant of the present application proposes to solve the problem of the TFD element by conversely using the disadvantage of niobium in the technical field of capacitors.

  That is, an object of the present invention is to provide a non-linear element that does not cause element breakdown even during continuous energization for a long time or when a high electric field is applied, an electro-optical device that drives a pixel electrode through the non-linear element, and the electro-optical device It is providing the electronic device provided with.

  In order to solve the above problems, in the present invention, in a nonlinear element comprising a lower electrode, an insulator formed on the surface of the lower electrode, and an upper electrode facing the lower electrode through the insulator The insulator is made of an oxide film of niobium (Nb) or a niobium alloy.

  In the present invention, the insulator is made of an oxide film of niobium or a niobium alloy, and such an oxide film has more defects than an oxide of tantalum. For this reason, although the leakage current is large, local breakdown of the insulator due to overcurrent occurs at the time of continuous energization for a long time or when a high electric field is applied, so that element breakdown does not occur. In the case of a non-linear element, unlike a capacitor, the capacitance may be small, so that the disadvantage of a large leakage current can be solved by increasing the thickness of the insulator. In addition, niobium or niobium alloy oxide film has a higher dielectric constant than tantalum oxide, but this point can also reduce the capacitance by increasing the thickness of the insulator. Can be prevented. Therefore, the nonlinear element to which the present invention is applied has characteristics higher than those of conventional nonlinear elements and has high reliability. Moreover, niobium has the advantage that it is cheaper than tantalum. Therefore, it is suitable for use in an apparatus having a large number of nonlinear elements on one substrate, such as an electro-optical device.

  In the present invention, a niobium alloy oxide film as well as an oxide film of a niobium alloy can be used as the insulating film, and an oxide film of an alloy of niobium and tantalum can be used as the oxide film of such an alloy. . Even when configured in this manner, there is an advantage that element destruction is less likely to occur compared to the case where a tantalum oxide film is used as an insulator.

  In the present invention, the lower electrode is made of niobium or a niobium alloy, and the oxide film may be a film formed by oxidizing the surface of the lower electrode. In this case, the oxide film may be a film formed by anodizing the surface of the lower electrode. Here, when the niobium / tantalum ratio in the niobium alloy is large, it is preferable to increase the thickness of the insulator.

  The nonlinear element according to the present invention can be used as a pixel switching nonlinear element in an electro-optical device, and in such an electro-optical device, a pixel electrode is driven via the nonlinear element.

  The electro-optical device according to the present invention is used in an electronic apparatus such as a mobile phone or a mobile computer.

  Embodiments of the present invention will be described with reference to the drawings.

[Nonlinear element]
(Element structure)
FIG. 1 is an enlarged longitudinal sectional view schematically showing the structure of a nonlinear element to which the present invention is applied. A nonlinear element 10 (TFD (Thin Film Diode) element) shown in FIG. 1 covers a lower electrode 13 formed on a substrate 11 made of glass, quartz, plastic, and the like, and covers the surface of the lower electrode 13. And an upper electrode 15 formed so as to cover the insulator 14. The upper electrode 15 faces the lower electrode 13 with the insulator 14 interposed therebetween. Here, a base film for improving the adhesion between the substrate 11 and the lower electrode 13 may be formed between the substrate 11 and the lower electrode 13.

  In this embodiment, the lower electrode 13 is made of niobium. Although the thickness of the lower electrode 13 is not specifically limited, For example, it is about 100-150 nm.

In this embodiment, the insulator 14 is composed of a niobium oxide film (NbO _x ), and the insulator 14 can be formed by anodizing the surface of the lower electrode 14 as will be described later. . In the present embodiment, the insulator 14 is configured to cover the entire surface of the lower electrode 13, and is also formed on the side edge 130 of the lower electrode 13. However, it is not necessary for the insulator 14 to cover the entire surface of the lower electrode 13, and if the lower electrode 13 and the upper electrode 15 are formed in a portion facing each other, the nonlinear element 10 can be configured. The thickness of the insulator 14 is usually desirably about 20 to 40 nm.

  The upper electrode 15 can be made of an appropriate metal material, but is preferably made of Cr, Mo, W or the like because of low wiring resistance and stability of characteristics. At this time, if the insulator 14 is also formed on the side edge 130 of the lower electrode 13 (the lowermost portion of the side surface of the lower electrode 13), the upper electrode 15 is placed on the insulator 14 above the side edge 130. Can be formed continuously over the lower ground of the lower electrode 13 (the surface of the substrate 11 in the illustrated example) through the upper electrode 15 and other layers (for example, pixel electrodes and other wirings). This facilitates the conductive connection. The thickness of the upper electrode 15 is not particularly limited, but is preferably about 100 to 500 nm. In general, as the thickness increases, the wiring resistance decreases. Therefore, it is preferable for preventing vertical crosstalk particularly in the case of configuring a liquid crystal display device. However, since the film formation time and the patterning time also increase, the thickness within the above range. It is desirable that it is.

(Device manufacturing method)
A method for manufacturing the nonlinear element 10 to which the present invention is applied will be described.

  FIG. 2 is a process diagram showing a method for manufacturing a nonlinear element to which the present invention is applied. As shown in FIG. 2, in the non-linear element manufacturing process P1, first, the material of the lower electrode 13 is formed on the substrate 11 by a sputtering method in step S01, and then the layer formed in step S02 is formed by photolithography. The lower electrode 13 is formed by patterning using a lithography method or the like. The sputtering method is performed with an RF sputtering apparatus or a magnetron sputtering apparatus. More specifically, a raw material (niobium) target for the lower electrode is placed in the chamber, the inside of the chamber is depressurized by an exhaust device such as a vacuum pump, and an inert gas such as argon is introduced. Is applied to form a plasma, and positive ions in the plasma are accelerated and collided with the target, and the target material is deposited on the substrate 11 by the reaction. The formation of the lower electrode 13 is not limited to the sputtering method, and the lower electrode 13 may be formed using another film forming method such as an evaporation method or a CVD method.

  Next, in step S03, the insulator 14 is formed on the surface of the lower electrode 13 by anodic oxidation. In this step, the insulator 14 made of a niobium anodic oxide film is formed by anodizing the surface of the lower electrode 13. In this anodic oxidation method, the substrate is immersed in an electrolyte solution (chemical conversion solution) such as an aqueous solution of phosphate, citrate, aromatic carboxylate, or alcohol solution, and is opposed to the cathode plate in the electrolyte. Thus, a voltage is applied between the lower electrode 13 and the cathode plate through an energization pattern (not shown). Examples of the aromatic carboxylate include ammonium salicylate, ammonium benzoate, ammonium γ-resorcinate, ammonium hydrogen phthalate, diammonium phthalate, and the like. At this time, since the current flows easily when the surface of the lower electrode 13 is exposed, normally, a voltage is first applied under constant current control (or connected to a constant current source) (constant current oxidation process). ) When anodization progresses and an oxide film with a certain thickness is formed on the surface of the lower electrode 13 and the voltage rises to a predetermined value, it is connected under a constant voltage control (or connected to a low voltage source). The method of continuing the oxidation treatment (constant voltage oxidation process) is employed. Here, the constant voltage oxidation process has the aim of stabilizing the film density, reducing the surface roughness of the insulator 14, and controlling the film thickness. As a result, the film quality of the insulator 14 is improved, and the electrical characteristics of the nonlinear element 10 are improved and stabilized.

  Next, in step S04, in order to improve the film quality and insulation of the insulator 14, to reduce variations in element characteristics and to obtain stability over time of the element characteristics, at 320 to 400 ° C. for about 10 to 120 minutes, Heat treatment (annealing) is performed.

  Thereafter, a process of forming the upper electrode 15 is performed. That is, in step S05, Cr is deposited on the surface of the substrate 11 by sputtering or the like, and then in step S06, a mask is formed thereon by photolithography using a resist or the like, and etching is performed through this mask. Thus, patterning is performed to form the upper electrode 15.

(Operation and effect of this form)
FIG. 3 is an explanatory view schematically showing the effect of the nonlinear element to which the present invention is applied. In the nonlinear element 10 of this embodiment, the insulator 14 is composed of a niobium oxide film, and the oxide film has a larger number of defects than the tantalum oxide film, so that the leakage current is large. FIG. 3A schematically shows the state in which the insulator 14 is composed of a tantalum anodic oxide film in the nonlinear element 10, and the case where the insulator 14 is composed of a niobium anodic oxide film in the nonlinear element 10. Is schematically shown in FIG.

  However, as shown in FIG. 3 (a), when the insulator 14 is made of a tantalum anodic oxide film, there are few defects, and this is caused by overcurrent during continuous energization for a long time or application of a high electric field. Since breakdowns that occur are concentrated, element breakdown is likely to occur. On the other hand, when the insulator 14 is composed of a niobium anodic oxide film, there are many defects, as shown in FIG. Since breakdown due to current occurs in a dispersed manner, element breakdown is unlikely to occur.

  Also, in the case of the nonlinear element 10, unlike the capacitor, the capacitance may be small. Therefore, as shown in FIG. 3C, if the insulator 14 is made thicker, the defect density is high but the potential gradient is high. Since it is small, the leakage current is small. Further, if the insulator 14 is made thick, element breakdown due to overcurrent hardly occurs during continuous energization for a long time or application of a high electric field. In addition, the niobium alloy oxide film has a higher dielectric constant than the tantalum oxide. However, since the capacitance can be lowered by increasing the thickness of the insulator 14, the resistance of the element can be reduced. Decline can be prevented. Moreover, niobium has the advantage that it is cheaper than tantalum. Therefore, it is suitable for use in an apparatus including a large number of nonlinear elements 10 on one substrate, such as an electro-optical device.

(Modification)
In the above embodiment, the example in which the lower electrode 13 is made of niobium and the insulator 14 is made of a niobium oxide film (NbO _x ) has been described. However, the lower electrode 13 is made of a niobium alloy and the insulator 14 is made of a niobium alloy. You may comprise with an oxide film. Such a niobium alloy is, for example, an alloy of niobium and tantalum. In such an alloy, it is preferable to increase the thickness of the insulator 14 as the ratio of niobium / tantalum increases. Since the niobium oxide has a higher dielectric constant than the tantalum oxide, the larger the niobium / tantalum ratio, the higher the dielectric constant of the insulator 14. However, the thickness of the insulator 14 is increased. By doing so, the capacitance value can be reduced, so that a reduction in the element resistance of the nonlinear element 10 can be prevented.

[Configuration of electro-optical device]
(overall structure)
FIG. 4 is a block diagram showing an electrical configuration of an electro-optical device (liquid crystal device) to which the present invention is applied. FIG. 5 is a cross-sectional view schematically showing the configuration of the electro-optical device.

  As shown in FIG. 4, in the electro-optical device 100 of this embodiment, a plurality of scanning lines 51 are formed extending in the row (X) direction, and a plurality of data lines 52 are arranged in the column (Y) direction. It is formed to extend. Further, pixels 53 are formed at positions corresponding to the intersections of the scanning lines 51 and the data lines 52, and these pixels 53 are arranged in a matrix. In each pixel 53, the liquid crystal layer 54 and the nonlinear element 10 (TFD element) described with reference to FIGS. 1 to 3 are connected in series. In the example illustrated in FIG. The non-linear elements 10 are respectively connected to the data line 52 side. The liquid crystal layer 54 may be connected to the data line 52 side, and the nonlinear element 10 may be connected to the scanning line 51 side. Each scanning line 51 is driven by a scanning line driving circuit 57, while each data line 52 is driven by a data line driving circuit 58.

  Specifically, such an electro-optical device 100 is configured as shown in FIG. 5, for example. Here, of the pair of substrates arranged opposite to each other, one substrate is the element substrate 20 on which the nonlinear element 10 and the pixel electrode are formed, and the other substrate is the counter substrate 30. Among these substrates, on the inner surface of the element substrate 20, a plurality of data lines 52, a plurality of nonlinear elements 10 connected to the data lines 52, and a one-to-one connection with the nonlinear elements 10 are connected. The pixel electrode 23 to be formed is formed. The data lines 52 are formed so as to extend in a direction perpendicular to the paper surface in FIG. 5, while the nonlinear elements 10 and the pixel electrodes 23 are arranged in a dot matrix. An alignment film 24 subjected to uniaxial alignment processing, for example, rubbing processing, is formed on the surface of the pixel electrode 23 and the like.

  A color filter 38 is formed on the inner surface of the counter substrate 30 and constitutes a colored layer of three colors “R”, “G”, and “B”. Note that a black matrix 39 is formed in the gap between the colored layers of these three colors to block incident light from the gap between the colored layers. A planarizing film 37 is formed on the surfaces of the color filter 38 and the black matrix 39, and a counter electrode 31 functioning as a scanning line 51 is formed on the surface in a direction perpendicular to the data lines 52. The planarizing film 37 is provided for the purpose of improving the smoothness of the color filter 38 and the black matrix 39 and preventing the counter electrode 31 from being disconnected. Further, an alignment film 34 that has been subjected to a rubbing process is formed on the surface of the counter electrode 31. The alignment films 24 and 34 are generally made of polyimide or the like.

  The element substrate 20 and the counter substrate 30 are bonded to each other with a predetermined gap by a sealing material 104 including a spacer (not shown), and the liquid crystal 105 is sealed in the gap. A polarizing plate 217 having an optical axis corresponding to the rubbing direction to the alignment film 24 is attached to the outer surface of the element substrate 20, and the outer surface of the counter substrate 30 corresponds to the rubbing direction to the alignment film 34. A polarizing plate 317 having an optical axis is attached. Note that the electro-optical device 100 according to this embodiment employs a COG (Chip On Glass) technique, and the liquid crystal driving IC chip 260 is mounted directly on the surface of the element substrate 20.

(Pixel configuration)
FIG. 6 is a plan view showing a layout for several pixels including a non-linear element in the electro-optical device, and FIG. 7 is an explanatory diagram of the non-linear element formed in each pixel.

  As shown in FIGS. 6 and 7, the nonlinear element 10 of the present embodiment includes a first nonlinear element 10 a and a second nonlinear element 10 b, and is formed on the lower layer 201 formed on the surface of the element substrate 20. The electrode 13 includes an insulator 14 made of an oxide film formed on the surface of the lower electrode 13 by anodic oxidation, and upper electrodes 15a and 15b formed on the surface and spaced apart from each other. The upper electrode 15 a is formed integrally with the metal layer 15 c that becomes the data line 52 as it is, while the upper electrode 15 b is connected to the pixel electrode 23. The data line 52 includes a metal layer 13 a that is formed simultaneously with the lower electrode 13. The underlayer 201 is made of an insulating film such as a niobium oxide film having a thickness of about 50 to 200 nm, for example.

  As described with reference to FIGS. 1 to 3, in the nonlinear element 10 of the present embodiment, the metal layer 13 a and the lower electrode 13 are formed of, for example, a niobium film having a thickness of about 100 to 150 nm, and the insulator 14. Is an anodized film having a thickness of 20 to 40 nm formed by oxidizing the surface of the metal layer 13a and the lower electrode 13 by an anodic oxidation method. The upper electrodes 15a and 15b are formed to a thickness of about 100 to 500 nm by a metal film such as chromium (Cr).

  Here, when viewed from the data line 52 side, the first non-linear element 10a becomes, in order, an upper electrode 15a / insulator 14 / lower electrode 13, and metal (conductor) / insulator / metal (conductor). ), A diode switching characteristic is obtained. On the other hand, when viewed from the data line 52 side, the second nonlinear element 10b is, in turn, the lower electrode 13 / insulator 14 / upper electrode 15b, and the diode switching characteristic opposite to that of the first nonlinear element 10a. Will have. Therefore, since the nonlinear element 10 has a configuration in which two diodes are connected in series in opposite directions, the current-voltage nonlinear characteristics are symmetric in both positive and negative directions compared to the case where one diode is used. Will be. If it is not necessary to strictly symmetrize the nonlinear characteristics as described above, only one nonlinear element may be used.

  The pixel electrode 23 is formed of a conductive transparent film such as ITO (Indium Tin Oxide) when used as a transmissive type, while having a reflectivity such as aluminum or silver when used as a reflective type. It may be formed from a large reflective metal film. Note that the pixel electrode 23 may be formed of a transparent metal such as ITO even if it is a reflective type. In this case, after the reflective metal as the reflective layer is formed, the transparent pixel electrode 23 is formed through the insulating layer. On the other hand, when it is used as a transflective type, the reflective layer is formed thin to form a transflective film, or a slit is provided. As the element substrate 20 itself, for example, an insulating substrate such as quartz or glass is used. When used as a transmission type, the element substrate 20 is also required to be transparent, but when used as a reflection type, it is not necessary to be transparent. The reason why the base layer 201 is provided on the surface of the element substrate 20 is to prevent the lower electrode 13 and the like from being peeled from the base by heat treatment and to prevent impurities from diffusing into the lower electrodes 13 and 13a. . Therefore, if this does not cause a problem, the base layer 201 can be omitted.

(Method for manufacturing electro-optical device)
FIG. 8 is a process diagram illustrating an example of a method for manufacturing the electro-optical device 100 of the present embodiment. FIG. 9 is a process sectional view showing a part of the element substrate forming process.

  In this embodiment, when the electro-optical device 100 is manufactured, the element substrate forming process including the nonlinear element forming process P1 to the sealing material printing process P5 shown in FIG. 8 and the color filter forming process P6 to the rubbing process P10 are performed. It is performed separately from the substrate forming step. In addition, these steps are performed in a state of a large original substrate that can take a large number of the element substrate 20 and the counter substrate 30, but in the following description, the single substrate size and the large original substrate are not distinguished, and the element substrate 20 Also referred to as counter substrate 30.

  In this embodiment, the active element formation process P1 is first performed on the large-sized element substrate 20, thereby forming the data lines 52 and the nonlinear elements 10 for a plurality of electro-optical devices. In the active element forming step P1, first, in the underlayer forming step (a) shown in FIG. 9, an insulating film such as niobium oxide is formed on the surface of the large element substrate 20 to have a uniform thickness. The formation 201 is formed.

  Next, in the first metal layer forming step (b), for example, niobium is formed into a uniform thickness by sputtering or the like, and further, the metal layer 13a of the data line 52 and the nonlinear element 10 are formed using photolithography technology. The lower electrode 13 is simultaneously formed (corresponding to the lower electrode forming step shown in FIG. 2). At this time, the metal layer 13a of the data line 52 and the lower electrode 13 are connected by a bridge portion (not shown). In this step, a power feeding pattern (not shown) is also formed.

  Next, in the insulating layer formation step (c), power is supplied to the element substrate 20 in a state where the large element substrate 20 is immersed in the electrolytic solution in the electrolytic bath, and anodization is performed (an anodization process shown in FIG. 2). Equivalent to At that time, power is supplied to the lower electrode 13 through the metal layer 13a of the data line 52, and an anodic oxide film acting as the insulator 14 is formed on the surface thereof.

  Next, in the annealing step (d), the element substrate 20 is heated in a heating furnace (corresponding to the heat treatment step shown in FIG. 2). As a result, since the defect density such as dislocations and vacancies in the insulator 14 is reduced, the I / V value of the nonlinear element 10 can be increased. Such an annealing process is performed at, for example, 400 ° C. in a nitrogen atmosphere.

  Next, in the second metal layer forming step (e), after Cr is deposited with a uniform thickness by sputtering or the like, the metal layer 15c as the uppermost layer of the data line 52 is formed by using a photolithography technique. The upper electrode 15a of the first nonlinear element 10a and the upper electrode 15b of the second nonlinear element 10b are formed (corresponding to the upper electrode forming step shown in FIG. 2). As described above, a required number of nonlinear elements 10 as active elements are formed on the surface of the element substrate 20.

  Next, in the bridge portion removal and underlayer removal step (f), the bridge portion is removed from the large element substrate 20 by dry etching, for example. Thereby, the lower electrode 13 and the insulator 14 of the first nonlinear element 10a and the second nonlinear element 10b are separated from the data line 52 in an island shape. In this step, in addition to the bridge portion, unnecessary portions that remain on the element substrate 20 when the large element substrate 200 is cut are also removed from the power feeding pattern. Further, the base layer 201 in the region corresponding to the pixel electrode 23 is removed.

  Next, the pixel electrode formation process P2 of FIG. 8 is performed. Specifically, in the electrode formation step (g), ITO for forming the pixel electrode 23 is formed with a uniform thickness by sputtering or the like, and further, the size of one pixel is obtained by photolithography. A corresponding pixel electrode 23 having a predetermined shape is formed so as to partially overlap the upper electrode 15b. Through the series of steps, the nonlinear element 10 and the pixel electrode 23 shown in FIGS. 6 and 7 are formed.

  After that, in the alignment film process P3 in FIG. 8, the alignment film 24 is formed on the surface of the original substrate 200 by forming a uniform thickness of polyimide, polyvinyl alcohol, etc., and then in the rubbing treatment process P4, the alignment film is aligned. The film 24 is subjected to a rubbing process or other alignment process.

  Next, in the sealing material printing process P5, the sealing material 104 is annularly applied by a dispenser, screen printing, or the like. Note that a liquid crystal injection port is formed in part of the sealing material 104.

  Separately from the above element substrate forming process, an opposing substrate forming process (color filter forming process P6 to rubbing process P10) is performed. For this purpose, first, a large counter substrate 30 formed of a light-transmitting material such as a glass substrate is prepared, and then a black matrix 39 and a color filter are formed on the surface of the large counter substrate 30 in a color filter forming step P6. 38 is formed. Here, when color display is not necessary, the color filter 38 need not be formed.

  Next, in the flattening layer forming step P7, the flattening film 37 is formed to a uniform thickness on the color filter 38 to flatten the surface.

  Next, in the counter electrode forming step P8, the stripe-shaped counter electrode 31, that is, the scanning line 51 is formed using an ITO film or the like.

  Next, after an alignment film 34 having a uniform thickness is formed on the scanning lines 51 and the like with polyimide or the like in the alignment film formation process P9, a rubbing process or the like is performed on the alignment film 34 in the rubbing process P10. An orientation process is performed.

  After that, the large element substrate 200 and the large counter substrate 30 are aligned, and then bonded with the sealant 104 interposed therebetween (bonding step P11), and then the sealant 104 is cured by ultraviolet curing or other methods. (Sealant curing step P12). As a result, an empty panel structure including a plurality of liquid crystal devices is formed. Thereafter, the empty panel structure is cut into strip-like panel structures (primary cutting step P13). At the cut portion of the strip-shaped panel structure, the liquid crystal injection port consisting of the cut off portion of the sealing material 104 is opened to the outside. Therefore, after the liquid crystal is injected from the exposed liquid crystal injection port to the inside of the panel structure under reduced pressure. (Liquid crystal injection step P14) A sealing material such as resin is applied to each liquid crystal injection port to seal each liquid crystal injection port (injection port sealing step P15). In addition, since a liquid crystal adheres to a panel structure body by this process, the panel structure body which has finished injecting the liquid crystal is cleaned (cleaning process P16). Thereafter, the panel structure is further cut to cut out a plurality of electro-optical devices 100 (secondary cutting step P17). Thereafter, the liquid crystal driving IC chip 260 and the like are mounted on the electro-optical device 100 to complete the electro-optical device 100 (mounting process P18).

In this embodiment, the example in which the lower electrode 13 is made of niobium and the insulator 14 is made of a niobium oxide film (NbO _x ) has been described. However, the lower electrode 13 is made of a niobium alloy and the insulator 14 is made of You may comprise a niobium alloy oxide film. Such a niobium alloy is, for example, an alloy of niobium and tantalum.

(Embodiment of electronic device)
FIG. 10 is an explanatory diagram of a mobile phone showing an example of an electronic apparatus in which the electro-optical device according to the invention is mounted. As shown in FIG. 10, the cellular phone 90 has a plurality of operation buttons 91 and the electro-optical device 1 to which the present invention is applied. Note that the electro-optical device of this embodiment can be used for a mobile personal computer or the like in addition to a cellular phone.

It is an expanded vertical sectional view which shows typically the structure of the nonlinear element to which this invention is applied. It is process drawing which shows the manufacturing method of the nonlinear element to which this invention is applied. It is explanatory drawing which shows typically the effect of the nonlinear element to which this invention is applied. 1 is a block diagram showing an electrical configuration of an electro-optical device (liquid crystal device) to which the present invention is applied. It is sectional drawing which shows the structure of an electro-optical apparatus typically. FIG. 3 is a plan view showing a layout for several pixels including a nonlinear element in an electro-optical device. FIG. 4 is an explanatory diagram of nonlinear elements formed in each pixel in the electro-optical device. It is process drawing which shows an example of the manufacturing method of the electro-optical apparatus to which this invention is applied. It is process sectional drawing which shows a part of element substrate formation process among the manufacturing processes of the electro-optical apparatus to which this invention is applied. It is explanatory drawing of the mobile telephone as one Embodiment of the electronic device using the liquid crystal device which concerns on this invention.

Explanation of symbols

10, 10a, 10b Non-linear element, 13 Lower electrode, 14 Insulator, 15, 15a, 15b Upper electrode, 20 Element substrate, 23 Pixel electrode, 30 Counter substrate, 100 Electro-optical device

Claims (7)

In a nonlinear element comprising a lower electrode, an insulator formed on the surface of the lower electrode, and an upper electrode facing the lower electrode via the insulator,
The non-linear element, wherein the insulator is composed of an oxide film of niobium or a niobium alloy.   The nonlinear element according to claim 1, wherein the niobium alloy is an alloy of niobium and tantalum. The lower electrode is made of niobium or a niobium alloy,
The nonlinear element according to claim 1, wherein the oxide film is a film formed by oxidizing the surface of the lower electrode.   3. The nonlinear element according to claim 2, wherein when the niobium / tantalum ratio in the two-obtain alloy is large, the thickness of the insulator is increased.   The nonlinear element according to claim 3, wherein the oxide film is an anodized film formed by anodizing the surface of the lower electrode.   An electro-optical device comprising: the nonlinear element according to claim 1; and a pixel electrode driven through the nonlinear element.   An electronic apparatus comprising the electro-optical device according to claim 6.

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