JP2010224403A - Method of manufacturing active matrix substrate, active matrix substrate, electro-optical device, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a substrate in which an active matrix circuit is formed on both sides of a piece of substrate. <P>SOLUTION: The method of manufacturing the active matrix substrate includes a first step of forming a first active matrix circuit on a first side of the substrate 1, and a second step of forming a second active matrix circuit including an organic transistor on a second side opposite to the first side of the substrate 1 after the first step. Thus, the active matrix substrate having functions on both sides can be made by more lightweight and at lower cost in comparison with a method of laminating two pieces of substrates which are separately made. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  One embodiment according to the present invention relates to a method for manufacturing an active matrix substrate, an active matrix substrate, an electro-optical device, and an electronic apparatus.

  In recent years, devices having a display capable of displaying on both front and back surfaces have been developed in order to increase the functionality of electronic devices (see, for example, Patent Documents 1 to 3).

JP 2007-128098 A JP 2001-22303 A JP 2001-22294 A

  In order to realize the above display, when two substrates on which elements such as transistors are formed are bonded together, there is a problem that the weight increases. On the other hand, when an element such as a transistor is formed not only on the front surface of the substrate but also on the back surface, degradation of the element due to process damage at the time of forming the transistor becomes a problem.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples or forms.

  Application Example 1 A first step of forming a first active matrix circuit on a first surface of a substrate, and an organic transistor on a second surface of the substrate opposite to the first surface after the first step. A second step of forming a second active matrix circuit comprising: an active matrix substrate manufacturing method.

  Since the active matrix circuit is formed on both sides of a single substrate in this way, it is lighter and cheaper and has functions on both sides compared to the method of bonding two separately created substrates. A matrix substrate can be created. Further, even when an active matrix circuit is formed on the same substrate, it is possible to minimize the process damage to the active matrix circuit on the first surface by making the second surface an active matrix circuit by an organic transistor. Become. This is because the organic transistor can be formed by a low damage process such as a printing method or a mask vapor deposition method, and there is no need to use a process that easily damages the entire substrate, such as heat treatment at high temperature, plasma treatment, or solution treatment. Alternatively, even if it is used, the entire substrate is very low in damage due to low energy.

  Application Example 2 The first step includes a step of forming a first scan line and a first data line that intersects the first scan line, and the second step is a second scan. Forming a line and a second data line intersecting the second scanning line, wherein the arrangement pitch of the second scanning lines is an integral multiple of the arrangement pitch of the first scanning lines. A method for manufacturing an active matrix substrate.

  Application Example 3 The first step includes a step of forming a first scanning line and a first data line intersecting the first scanning line, and the second step is a second scanning. Forming a line and a second data line intersecting the second scanning line, wherein the arrangement pitch of the second data lines is an integral multiple of the arrangement pitch of the first data lines. A method for manufacturing an active matrix substrate.

  Thereby, the component of a 1st active matrix circuit and the component of a 2nd active matrix circuit can be linked | related easily. For example, it can be used more accurately in applications that use the positional correlation between the first and second surfaces, such as detecting the location indicated by the light pen with the light sensor on the second surface and changing the display on the first surface. You will be able to identify the location. Further, in the process of forming the active matrix circuit on the second surface, since the influence on the process derived from the active matrix circuit on the first surface becomes periodic, the active matrix circuit on the second surface can be formed with higher yield.

  Application Example 4 A method for manufacturing an active matrix substrate, further comprising a step of electrically connecting the second scanning line to the first scanning line.

  Application Example 5 A method for manufacturing an active matrix substrate, further comprising a step of electrically connecting the second data line to the first data line.

  As a result, the number of various signal lines, switches, and wirings can be reduced, and cost reduction and yield improvement can be expected. Further, for example, the number of scan drivers and data drivers required for driving the first surface and the second surface can be saved, and the manufacturing cost can be reduced.

  Application Example 6 includes a substrate, a first active matrix circuit formed on the first surface of the substrate, and an organic transistor formed on the second surface of the substrate opposite to the first surface. An active matrix substrate having a second active matrix circuit.

  Since the active matrix circuit is formed on both sides of one substrate in this way, the active matrix has functions on both sides at a lower weight and at a lower cost than a structure in which two separately prepared substrates are bonded together. A substrate is obtained.

  Application Example 7 The first active matrix circuit includes a first scanning line and a first data line that intersects the first scanning line, and the second active matrix circuit includes a first scanning line. Two scanning lines and a second data line intersecting the second scanning line, and the arrangement pitch of the second scanning lines is an integral multiple of the arrangement pitch of the first scanning lines. Active matrix substrate.

  Application Example 8 The first active matrix circuit includes a first scanning line and a first data line that intersects the first scanning line, and the second active matrix circuit includes a first scanning line. Two scanning lines and a second data line intersecting the second scanning line, and the arrangement pitch of the second data lines is an integral multiple of the arrangement pitch of the first data lines. Active matrix substrate.

  Thereby, the component of a 1st active matrix circuit and the component of a 2nd active matrix circuit can be linked | related easily.

  Application Example 9 An active matrix substrate in which the second scanning line is electrically connected to the first scanning line.

  Application Example 10 An active matrix substrate in which the second data line is electrically connected to the first data line.

  As a result, the number of various signal lines, switches, and wirings can be reduced, and cost reduction and yield improvement can be expected. Further, for example, the number of scan drivers and data drivers required for driving the first surface and the second surface can be saved, and the manufacturing cost can be reduced.

  Application Example 11 An active matrix substrate in which the first active matrix circuit includes any of an amorphous silicon transistor, a polysilicon transistor, an oxide transistor, and an organic transistor.

  By using these high-performance thin film transistors, a high-performance active matrix circuit can be formed on the first surface side of the substrate.

  Application Example 12 An active matrix substrate in which at least one of an optical sensor, a magnetic sensor, a temperature sensor, a pressure sensor, and a memory circuit is formed in the second active matrix circuit.

  As a result, various elements, circuits, and devices formed on the first surface can be driven using the optical sensor, magnetic sensor, temperature sensor, pressure sensor, memory circuit, and the like formed on the second surface. .

  Application Example 13 An electro-optical device provided with the active matrix substrate.

  Application Example 14 An electro-optical device in which any one of a liquid crystal display, an electrophoretic display, an organic EL display, an inorganic EL display, and an electrochromic display is formed on the first active matrix circuit.

  As a result, an electro-optical device having good display characteristics can be formed on the first surface side of the substrate.

  Application Example 15 An electro-optical device in which any one of a liquid crystal display, an electrophoretic display, an organic EL display, an inorganic EL display, and an electrochromic display is formed on the second active matrix circuit.

  Thus, an electro-optical device capable of displaying not only on the first surface side of the substrate but also on the second surface side is obtained.

  Application Example 16 Electronic equipment including the electro-optical device.

  According to such a configuration, an electronic device including a display device, a television device, electronic paper, a clock, a calculator, a mobile phone, a portable information terminal, and the like can be created.

1 is a schematic cross-sectional view of an electro-optical device. Sectional drawing of a microcapsule. The top view of a 1st pixel circuit. Sectional drawing which shows the manufacturing process of a 1st pixel circuit. Sectional drawing which shows the manufacturing process of a 1st pixel circuit. The top view of a 2nd pixel circuit. Sectional drawing which shows the manufacturing process of a 2nd pixel circuit. Sectional drawing which shows the manufacturing process of a 2nd pixel circuit. The perspective view of an electronic notebook.

  Hereinafter, embodiments of an active matrix substrate manufacturing method, an active matrix substrate, an electro-optical device, and an electronic apparatus will be described with reference to the drawings. Hereinafter, as an example of an electro-optical device, a device including a liquid crystal display on the first surface and an electrophoretic display on the second surface will be described.

  FIG. 1 is a schematic cross-sectional view of the electro-optical device 100. The electro-optical device 100 includes a substrate 1, and a counter substrate 21 having a light transmitting property and disposed opposite to the substrate 1 via a frame-shaped sealing material 22. The substrate 1, the counter substrate 21, and the seal A liquid crystal 23 is sealed in a region surrounded by the material 22. A first active matrix circuit is formed on a surface of the substrate 1 on the liquid crystal 23 side (also referred to as a first surface). The first active matrix circuit has a first pixel circuit including a light-reflective first pixel electrode 11. A first common electrode 24 facing the plurality of first pixel electrodes 11 is formed on the surface of the counter substrate 21 on the liquid crystal 23 side. The first common electrode 24 is made of a light-transmitting member such as ITO. A polarizing plate (not shown) is arranged on the surface of the counter substrate 21 opposite to the first common electrode 24. The liquid crystal 23 changes the alignment state according to the voltage generated between the first pixel electrode 11 and the first common electrode 24. Polarized light that has entered through the polarizing plate from the counter substrate 21 side is reflected by the first pixel electrode 11, converted into polarized light according to the alignment state of the liquid crystal 23, and transmitted or shielded when passing through the polarizing plate again. . By controlling this action for each first pixel electrode 11, display is performed. In other words, the electro-optical device 100 can perform display using the liquid crystal 23 on the counter substrate 21 side.

  On the other hand, a second active matrix circuit is formed on a surface of the substrate 1 opposite to the counter substrate 21 (also referred to as a second surface). The second active matrix circuit has a second pixel circuit including the second pixel electrode 38. Therefore, the first pixel circuit is formed on the first surface of the substrate 1, and the second pixel circuit is formed on the second surface opposite to the first pixel circuit. On the second pixel electrode 38, an electrophoretic sheet 41 including microcapsules 42 is disposed. A binder 43 is disposed between the adjacent microcapsules 42. A second common electrode 47 is disposed on the opposite side of the second pixel electrode 38 with the electrophoretic sheet 41 interposed therebetween. The second common electrode 47 is made of a light-transmitting member such as ITO.

  FIG. 2 is a cross-sectional view of the microcapsule. Inside each microcapsule 42, a white electrophoretic display device 45 and black electrophoretic particles 46 dispersed in a liquid phase dispersion medium 44 are enclosed. White electrophoretic particles 45 are negatively charged, and black electrophoretic particles 46 are positively charged.

  In such a configuration, by setting the potential of the second pixel electrode 38 to be higher than the potential of the second common electrode 47, the black electrophoretic particles 46 are moved to the second common electrode 47 side and are also subjected to white electrophoretic migration. When the particles 45 move to the second pixel electrode 38 side and are observed from the second common electrode 47 side, they are visually recognized as black display. Further, by setting the potential of the second pixel electrode 38 to be lower than the potential of the second common electrode 47, the white electrophoretic particles 45 are placed on the second common electrode 47 side, and the black electrophoretic particles 46 are placed on the first common electrode 47 side. When moving to the two-pixel electrode 38 side and observing from the second common electrode 47 side at this time, it is visually recognized as white display. By controlling this action for each second pixel electrode 38, display is performed. That is, the electro-optical device 100 can perform display using the electrophoretic sheet 41 on the electrophoretic sheet 41 side. Therefore, the electro-optical device 100 is a device capable of double-sided display that includes a liquid crystal display on the first surface side of the substrate 1 and an electrophoretic display on the second surface side.

  Next, a method for manufacturing the electro-optical device 100 will be described. The method of manufacturing the electro-optical device 100 includes a step of forming a first active matrix circuit including a first pixel circuit on the first surface of the substrate 1 (first step), and a second pixel circuit on the second surface of the substrate 1. Forming a second active matrix circuit including (step 2). FIG. 3 is a plan view of the first pixel circuit, and FIGS. 4 and 5 are cross-sectional views taken along line AA of FIG. 3 showing the manufacturing process of the first pixel circuit. FIG. 6 is a plan view of the second pixel circuit, and FIGS. 7 and 8 are cross-sectional views taken along the line BB of FIG. 6 showing the manufacturing process of the second pixel circuit.

  As shown in FIG. 3, the first pixel circuit includes a plurality of scanning lines 4 (gate electrodes), a plurality of data lines 8 arranged so as to intersect the scanning lines 4, and the scanning lines 4 and 8. It has a polysilicon TFT 25 provided corresponding to the intersection, and a first pixel electrode 11 electrically connected to the polysilicon TFT 25. The scanning line 4 corresponds to the first scanning line, and the data line 8 corresponds to the first data line. The polysilicon TFT 25 includes the polysilicon film 2. The polysilicon film 2 is electrically connected to the data line 8 through the contact hole 7 and electrically connected to the first pixel electrode 11 through the contact hole 10. The first pixel electrode 11 has a rectangular shape, and a region where the three adjacent pixel electrodes 11 are combined has a substantially square shape. The three first pixel electrodes 11 constituting a substantially square contribute to, for example, red, green, and blue display, respectively.

  First, referring to FIGS. 4 and 5, a method of forming an active matrix circuit including a first pixel circuit having a polysilicon TFT 25 formed on the first surface of the substrate 1 will be described.

  For the substrate 1, a substrate such as a quartz substrate, a glass substrate, a stainless steel substrate, or a plastic substrate can be used. The substrate 1 may have flexibility. As the plastic substrate, a substrate made of either a thermoplastic resin or a thermosetting resin may be used. For example, polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA), cyclic polyolefin, modified polyolefin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polyamideimide, Polycarbonate, poly- (4-methylbenten-1), ionomer, acrylic resin, polymethyl methacrylate, acrylic-styrene copolymer (AS resin), butadiene-styrene copolymer, polio copolymer (EVOH), polyethylene Polyester such as terephthalate, polybutylene terephthalate, polyethylene naphthalate, precyclohexane terephthalate (PCT), polyether, polyetherketone, polyetheretherketone Polyetherimide, polyacetal, polyphenylene oxide, modified polyphenylene oxide, polyarylate, aromatic polyester (liquid crystal polymer), polytetrafluoroethylene, polyvinylidene fluoride, other fluororesins, styrene, polyolefin, polyvinyl chloride, polyurethane , Fluoroelastomers, chlorinated polyethylene, and other thermoplastic elastomers, epoxy resins, phenolic resins, urea resins, melamine resins, unsaturated polyesters, silicone resins, polyurethanes, etc., or copolymers and blends mainly composed of these The body, a polymer alloy, etc. are mentioned, The laminated body which laminated | stacked 1 type or 2 types or more among these can be used. An insulating layer (not shown) may be provided on one surface of the substrate. As the insulating layer, any known film can be used as long as it is an insulating thin film. For example, a polymer film such as polymethyl methacrylate, polyvinyl phenol, polyimide, polystyrene, polyvinyl alcohol, and polyvinyl acetate. Or inorganic materials such as organic materials such as parylene films, metal oxides such as silicon oxide, silicon nitride, aluminum oxide, and tantalum oxide, and metal composite oxides such as barium strontium titanate and lead zirconium titanate. These can be used alone or in combination of two or more.

  After the substrate 1 cleaning process, an amorphous silicon film is deposited on the substrate 1. This can be realized, for example, by holding the substrate 1 together with silane in the LPCVD system at a temperature of about 450 degrees. In this case, the deposited film thickness is desirably about 50 nm to 200 nm. Next, excimer laser irradiation is performed to crystallize the amorphous silicon film into a polycrystalline film. Thereafter, a polysilicon film 2 is formed through patterning by photolithography (FIG. 4A).

  Next, a gate insulating film 3 is deposited on the polysilicon film 2 and over the surface of the substrate 1. The insulating material used for the gate insulating film 3 is preferably silicon dioxide deposited by chemical vapor deposition (CVD) such as plasma enhanced CVD (PECVD) or low pressure CVD (LPCVD). The thickness of the gate insulating film 3 is preferably 50 nm to 200 nm (FIG. 4B).

  Thereafter, a conductive metal thin film such as AL (aluminum) is deposited on the gate insulating film 3 by sputtering. Then, the scanning line 4 (gate electrode) is formed on the channel portion of the polysilicon film 2 by using the lithography method and the dry etching method (FIG. 4C).

Next, using the scanning line 4 (gate electrode) as a mask, impurities are introduced into the source / drain region by ion doping using an ion doping method to form a doped silicon region 5 in the polysilicon film 2. For example, in the case of manufacturing an n-channel TFT, it is possible to introduce impurities at a plane density of energy 100 KeV and 5 × 10 ¹⁵ / cm ² by ion doping using PH 3 gas as a source gas (FIG. 4). (D)).

  In the next step, silicon dioxide is preferably formed as the first interlayer insulating film 6 over the entire surface of the device (on the gate insulating film 3 and on the scanning line 4) (FIG. 4E).

  Next, a contact hole 7 penetrating the first interlayer insulating film 6 and the gate insulating film 3 is formed by photoetching at a position overlapping one of the doped silicon regions 5 (FIG. 5A).

  Next, after depositing a conductive metal thin film such as AL on the first interlayer insulating film 6 by sputtering, photo etching is performed, and the data line 8 connected to the doped silicon region 5 through the contact hole 7. Is formed (FIG. 5B).

  In the next step, silicon dioxide is preferably formed over the entire surface of the device as the second interlayer insulating film 9. Thereafter, a contact hole 10 penetrating the second interlayer insulating film 9, the first interlayer insulating film 6, and the gate insulating film 3 is formed at a position overlapping the other of the doped silicon region 5 by photoetching (FIG. 5C). ).

  Subsequently, a first pixel electrode 11 made of ITO is formed so as to fill the contact hole 10. The first pixel electrode 11 is electrically connected to the doped silicon region 5 (drain electrode) through the contact hole 10 (FIG. 5D).

  A liquid crystal display can be formed on the active matrix substrate having the plurality of first pixel circuits thus formed by using an existing method. The step of forming the liquid crystal display element after forming the active matrix circuit on the first surface of the substrate 1 may be performed after the step of forming the active matrix circuit on the second surface of the substrate described below.

  Next, a process for forming an active matrix circuit having a second pixel circuit on the second surface of the substrate 1 will be described. In the description of FIGS. 6 to 8, the expression “on substrate 1” means on the second surface of substrate 1 unless otherwise specified.

  FIG. 6 is a plan view of the second pixel circuit. The second pixel circuit includes a plurality of scanning lines 39, a plurality of data lines 31 arranged so as to intersect the scanning lines 39, and an organic TFT 26 provided corresponding to the intersection of the scanning lines 39 and the data lines 31. And a pixel electrode (second pixel electrode in this example) 38 electrically connected to the organic TFT 26. The scanning line 39 corresponds to the second scanning line, and the data line 31 corresponds to the second data line. The organic TFT 26 includes a drain electrode 32 and an organic semiconductor film 33. The drain electrode 32 has two protrusions, and a portion including the protrusions overlaps the organic semiconductor film 33. The data line 31 has two protrusions protruding in a direction intersecting the extending direction of the data line 31, and a part of the protrusion overlaps the organic semiconductor film 33. The two protruding portions of the drain electrode 32 and the two protruding portions of the data line 31 are arranged such that one protruding portion is located between the other two protruding portions. . The scanning line 39 has a part protruding in a direction intersecting the extending direction of the scanning line 39, and this protruding part functions as the gate electrode 35 of the organic TFT 26. The gate electrode 35 is provided at a position that overlaps a region where the two protruding portions of the drain electrode 32 and the two protruding portions of the data line 31 are alternately arranged. The drain electrode 32 is electrically connected to a pixel electrode (second pixel electrode in this example) 38 through a contact hole 37. The pixel electrode (second pixel electrode in this example) 38 has a substantially square shape.

First, a conductive film is formed on the substrate 1 by, for example, a physical vapor deposition method such as a sputtering method or an evaporation method, and then the data line 31 and the drain electrode 32 are formed by performing photoetching of the conductive film ( FIG. 7 (a)).
In addition, the data line 31 and the drain electrode 32 can be formed without performing etching by performing a conductive film deposition process on the substrate through a metal through mask having a hole in a predetermined shape. Further, the data line 31 and the drain electrode can be obtained by dropping a polymer mixture containing conductive particles such as metal fine particles and graphite on the substrate 1 by a method such as an ink jet method and conducting a conductive treatment such as heat, light, or solution treatment. 32 may be formed, and when such a method is used, the data line 31 and the like can be formed more easily and at low cost.

As the conductive film used for forming the data line 31 and the drain electrode 32, for example, Cr, Al, Ta, Mo, Nb, Cu, Ag, Au, Pt, Pd, In, Ni, Nd or their metals are used. Alloys such as InO ₂ , SnO ₂ and ITO, conductive polymers such as polyaniline, polypyrrole, polythiophene and polyacetylene, and acids such as hydrochloric acid, sulfuric acid and sulfonic acid, PF ₆ , AsF ₅ , A material having conductivity, such as a Lewis acid such as FeCl ₃ , a halogen atom such as iodine, a dopant such as a metal atom such as sodium potassium, a conductive composite material in which carbon black or metal particles are dispersed, A film made of a mixture of these can be used. Different materials may be used for the data line 31 and the drain electrode 32.

  Next, an organic semiconductor film 33 is formed on the substrate 1 in a region including a region between the protruding portion of the data line 31 and the protruding portion of the drain electrode 32 (FIGS. 6 and 7B).

  Here, examples of the organic semiconductor film 33 include poly (3-alkylthiophene), poly (3-hexylthiophene) (P3HT), poly (3-octylthiophene), and poly (2,5-thienylene vinylene. ) (PTV), poly (para-phenylenevinylene) (PPV), poly (9,9-dioctylfluorene) (PFO), poly (9,9-dioctylfluorene-co-bis-N, N ′-(4- Methoxyphenyl) -bis-N, N′-phenyl-1,4-phenylenediamine) (PFMO), poly (9,9-dioctylfluorene-co-benzothiadiazole) (BT), fluorene-triallylamine copolymer, Fluorenes such as triallylamine-based polymers, poly (9,9-dioctylfluorene-co-dithiophene) (F8T2) Polymer organic semiconductor materials such as bithiophene copolymers, C60, metal phthalocyanines or substituted derivatives thereof, acene molecular materials such as anthracene, tetracene, pentacene, hexacene, or α-oligothiophenes, specifically Can be formed using a mixture of one or more of low molecular organic semiconductors such as quarterthiophene (4T), sexithiophene (6T), and octathiophene. Examples of a method for forming such an organic semiconductor film 33 include a vacuum deposition method, a spin coating method, a casting method, a pulling method, a Langmuir Blodget method, a spray method, an ink jet method, and a silk screen method. It is not limited.

  In addition, when forming the organic-semiconductor film | membrane 33 mentioned above, you may perform the substrate surface treatment for performing the film | membrane formation beforehand beforehand with respect to the surface of the board | substrate 1. FIG. As the substrate surface treatment, for example, surface treatment using a surface modifier such as hexamethyldisilazane, cyclohexene, octadecyltrichlorosilane, organic cleaning treatment using acetone, isopropyl alcohol, etc., acid such as hydrochloric acid, sulfuric acid, acetic acid, etc. And alkali treatment of sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, etc., UV ozone treatment, fluorination treatment, plasma treatment of oxygen, argon, etc., and Langmuir Blodgett film formation treatment. Species, or two or more treatments can be used. By performing this treatment, the uniformity of the formed organic semiconductor film can be further increased and a better interface can be formed, so that the device characteristics can be further improved.

  Next, a gate insulating film 34 that covers the data line 31, the drain electrode 32, and the organic semiconductor film 33 is formed on the substrate 1 (FIG. 7C). The material of the gate insulating film 34 is not particularly limited as long as it is an insulating material, and either an organic material or an inorganic material can be used. Known organic materials for gate insulating films include polymer films such as polymethyl methacrylate, polyvinyl phenol, polyimide, polystyrene, polyvinyl alcohol, polyvinyl acetate, and parylene films. Inorganic materials include silicon oxide and silicon nitride. In addition, metal oxides such as aluminum oxide and tantalum oxide, and metal composite oxides such as barium strontium titanate and lead zirconium titanate can be used, and one or more of these can be used in combination.

Next, a gate electrode 35 is formed on the gate insulating film 34 at a predetermined position that overlaps with the organic semiconductor film 33 and functions as a channel region of the thin film transistor (FIG. 8A). Further, a scanning line 39 (not shown in FIG. 8) integrated with the gate electrode 35 is also formed. Examples of the constituent material of the gate electrode 35 and the scanning line 39 include Cr, Al, Ta, Mo, Nb, Cu, Ag, Au, Pt, Pd, In, Ni, Nd, and alloys using those metals. Conductive oxides such as InO ₂ , SnO ₂ , ITO, conductive polymers such as polyaniline, polypyrrole, polythiophene, polyacetylene, and acids such as hydrochloric acid, sulfuric acid, sulfonic acid, PF ₆ , AsF ₅ , FeCl _3, etc. Examples thereof include materials having conductivity, such as those obtained by adding a dopant such as a Lewis atom, a halogen atom such as iodine, or a metal atom such as sodium potassium, or a conductive composite material in which carbon black or metal particles are dispersed. The formation method is the same as the data line 31 and the like described above, such as a method combining physical vapor deposition and photo etching, a method of performing vapor deposition through a metal through mask, a method of dropping a polymer mixture containing conductive particles, and the like. It can be adopted as appropriate.

  Next, an interlayer insulating film 36 covering the gate electrode 35 and the scanning line 39 (not shown) is formed on the gate insulating film 34, the gate electrode 35, and the scanning line 39 (FIG. 8B). The material of the interlayer insulating film 36 is not particularly limited as long as it is an insulating material, and any organic material or inorganic material can be used. Known organic materials for insulating films include polyester, polycarbonate, polyvinyl alcohol, polyacetal, polyarylate, polyamide, polyamideimide, polyolefin, polyetherimide, polyphenylene ether, polyphenylene sulfide, polyethersulfone, polyetherketone, polyphthalate. Amide, polyether nitrile, polyether sulfone, polybenzimidazole, polycarbodiimide, polysiloxane, polymethyl methacrylate, polymethacrylamide, nitrile rubber, acrylic rubber, polyethylene tetrafluoride, epoxy resin, urethane resin, phenol resin, melamine resin , Urea resin, polybutene, polypentene, polybutadiene, butyl rubber, polystyrene and copolymers thereof Inorganic materials include metal oxides such as silicon oxide, silicon nitride, aluminum oxide, and tantalum oxide, metal composite oxides such as barium strontium titanate, lead zirconium titanate, and the like. Examples thereof include silicon insulating films obtained from coating films of benzocyclobutene, polysilazane compounds, and polysilane compounds. One or more of these can be used in combination.

Next, a contact hole 37 is formed by partially removing the gate insulating film 34 and the interlayer insulating film 36 on the drain electrode 32 (FIG. 8C). For example, an etching mask having an opening overlapping at least part of the drain electrode 32 is formed on the insulating layer including the gate insulating film 34 and the interlayer insulating film 36, and etching is performed through the etching mask. Etching can be any method and type as long as it can remove the insulating layer and does not affect the element or drain electrode 32 on the substrate 1 already formed. For example, hydrofluoric acid, nitric acid, hydrochloric acid, sulfuric acid Wet etching with acids such as wet etching, wet etching with bases such as sodium hydroxide, potassium hydroxide, calcium hydroxide and ammonia, wet etching with aromatic solvents, ketone solvents and alcohol solvents, organic solvents, oxygen plasma, argon Any conventional etching technique such as plasma, dry etching using CF ₄ plasma, or machining using a press apparatus may be used.

  Incidentally, in the above method, the contact hole 37 is formed using the etching mask after the interlayer insulating film 36 is formed, but the method of forming the contact hole 37 is not limited to this. As another method, for example, a photosensitive material such as photosensitive polysilazane or a photocurable resin is used as the interlayer insulating film 36, and after the photosensitive material is formed on the entire surface of the substrate, the photosensitive material is exposed on the pattern. Thereafter, a method of directly forming the contact hole 37 by a solution treatment or the like, a method of printing an insulating material using a screen printing mask having a mask shape in which the contact hole 37 is formed, or the like can be used. .

Next, the pixel electrode 38 is formed. Most of the pixel electrode 38 is disposed at a predetermined position on the interlayer insulating film 36, and a part thereof is formed so as to be electrically connected to the drain electrode 32 through the contact hole 37 (FIG. 8D). ). As the constituent material of the pixel electrode 38, for example, Cr, Al, Ta, Mo, Nb, Cu, Ag, Au, Pt, Pd, In, Ni, Nd, alloys using these metals, etc., InO ₂ , SnO ₂ , etc. , Conductive oxides such as ITO, conductive polymers such as polyaniline, polypyrrole, polythiophene and polyacetylene, and acids such as hydrochloric acid, sulfuric acid and sulfonic acid, Lewis acids such as PF ₆ , AsF ₅ and FeCl ₃ , iodine and the like Materials having conductivity, such as those added with dopants such as metal atoms such as halogen atoms and sodium potassium, carbon black and conductive composite materials in which metal particles are dispersed. The formation method is the same as the data line 31 and the like described above, such as a method combining physical vapor deposition and photo etching, a method of performing vapor deposition through a metal through mask, a method of dropping a polymer mixture containing conductive particles, and the like. It can be adopted as appropriate.

In the above-described embodiment, the organic transistor using the organic semiconductor film 33 as an example of the transistor has been illustrated as having a top gate / bottom contact type structure, but other structures, specifically, Any of a top gate / top contact type structure, a bottom gate / bottom contact type structure, and a bottom gate / top contact type structure can be employed.
In addition, the formation process of the second active matrix circuit on the second surface can reduce the maximum temperature of the process due to the use of the organic semiconductor film 33, and is, for example, 200 ° C. or less. For this reason, damage to the first active matrix circuit previously formed on the first surface can be suppressed.

  Thereafter, an electrophoresis sheet 41 (see FIG. 1) and a second common electrode 47 (see FIG. 1) are formed on the substrate 1 by a known method, thereby completing the electrophoresis display on the second surface of the substrate 1. .

In the present embodiment, the liquid crystal display formed on the first surface has the same number of scanning lines as the electrophoretic display formed on the second surface, and the number of data lines is tripled.
Therefore, for example, by electrically connecting the scanning line 4 of the liquid crystal display formed on the first surface and the scanning line 39 of the electrophoretic display formed on the second surface so as to correspond one-to-one, the same It is possible to drive both displays formed on the first surface and the second surface using a driver for driving the display, and a cost reduction effect including reduction of the number of drivers and reduction of driver mounting process steps can be expected. The same effect can be expected for the data line.
Regarding a specific method of electrical connection between the scanning lines and the data lines formed on the first surface and the second surface, for example, a method of forming a through hole in the substrate 1 to electrically connect, Alternatively, it is possible to use a technique of electrical connection through a flexible printed circuit board mounted on each surface.

The relationship between the scanning lines 4 and the scanning lines 39 is not limited to the above, and the number of scanning lines 4 can be an integral multiple of the number of scanning lines 39. At this time, the arrangement pitch of the scanning lines 39 is preferably an integer multiple of the arrangement pitch of the scanning lines 4. In this way, the scanning line 39 can be easily electrically connected to the scanning line 4.
Further, the relationship between the data lines 8 and the data lines 31 is not limited to the above, and the number of the data lines 8 can be an integral multiple of the number of the data lines 31. At this time, the arrangement pitch of the data lines 31 is preferably an integral multiple of the arrangement pitch of the data lines 8. In this way, the data line 31 can be easily electrically connected to the data line 8.

  Since the second active matrix circuit formed on the second surface of the substrate 1 includes the organic TFT 26, it is difficult to increase the definition as compared with an active matrix circuit having a polysilicon TFT or the like. Therefore, when the resolution of the second active matrix substrate is different from the resolution of the first active matrix circuit formed on the first surface, the resolution of the second active matrix substrate is made lower, For example, the resolution is set to 200 dpi or less. By making the resolutions on both sides different, it is possible to create an electro-optical device having different display functions on the first surface and the second surface, for example. Alternatively, even when a sensor device such as a touch sensor is formed on the second surface, it is possible to form a device in which the display resolution of the first surface and the sensor resolution of the second surface are different.

Next, specific examples of electronic devices configured using the above-described electro-optical device will be described. FIG. 9 is a perspective view showing an electronic notebook to which the electro-optical device is applied. This electronic notebook 1000 has a notebook personal computer main body 1100 equipped with an input device and an electronic circuit, and a display unit 1200 connected thereto. The electro-optical device 100 described above is mounted on the display unit 1200. The display unit 1200 can be turned over by rotating the hinge portion 1300 as necessary, and either the liquid crystal display 1210 on the first surface or the electrophoretic display 1220 on the second surface can be directed to the viewer side. Accordingly, it can be used as a notebook computer using the liquid crystal display 1210 or an electronic book using the electrophoretic display 1220.
The use of the electronic device is not limited to this. For example, in addition to the above-described devices, those belonging to real estate such as wall surfaces and those belonging to moving bodies such as vehicles, flying objects, and ships are also applicable.

In the above-described embodiment, the mode in which the liquid crystal display and the electrophoretic display are respectively formed on the first surface and the second surface of the substrate 1 as the active matrix substrate is exemplified. However, the embodiment of the electro-optical device is as follows. It is not limited to this. On the first or second surface of the active matrix substrate, other displays such as organic EL (Electro Luminescence) display, inorganic EL display, electrochromic display, fingerprint sensor, optical sensor, magnetic sensor, temperature sensor, pressure sensor It is also possible to form a detection device such as a memory circuit.
Further, the first active matrix circuit formed on the first surface of the substrate 1 may include an amorphous silicon transistor, an oxide transistor, an organic transistor, and the like.

  DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Polysilicon film, 3 ... Gate insulating film, 4, 35 ... Gate electrode, 5 ... Doped silicon region, 6 ... First interlayer insulating film, 7, 10, 37 ... Contact hole, 8, 31 ... Data line, 9 ... second interlayer insulating film, 11 ... first pixel electrode, 21 ... counter substrate, 22 ... sealing material, 23 ... liquid crystal, 24 ... first common electrode, 32 ... drain electrode, 33 ... organic semiconductor film, 34 ... Gate insulating film, 36 ... Interlayer insulating film, 38 ... Pixel electrode, 39 ... Scanning line, 41 ... Electrophoresis sheet, 42 ... Microcapsule, 43 ... Binder, 44 ... Liquid phase dispersion medium, 45 ... White electrophoretic particles 46 ... black electrophoretic particles, 47 ... second common substrate, 100 ... electro-optical device.

Claims (16)

A first step of forming a first active matrix circuit on a first surface of the substrate;
A second step of forming, after the first step, a second active matrix circuit including an organic transistor on a second surface opposite to the first surface of the substrate;
A method for producing an active matrix substrate, comprising: The first step includes a step of forming a first scan line and a first data line intersecting the first scan line,
The second step includes a step of forming a second scan line and a second data line intersecting the second scan line,
2. The method of manufacturing an active matrix substrate according to claim 1, wherein the arrangement pitch of the second scanning lines is an integral multiple of the arrangement pitch of the first scanning lines. The first step includes a step of forming a first scan line and a first data line intersecting the first scan line,
The second step includes a step of forming a second scan line and a second data line intersecting the second scan line,
2. The method of manufacturing an active matrix substrate according to claim 1, wherein the arrangement pitch of the second data lines is an integral multiple of the arrangement pitch of the first data lines.   4. The method of manufacturing an active matrix substrate according to claim 2, further comprising a step of electrically connecting the second scanning line to the first scanning line.   4. The method of manufacturing an active matrix substrate according to claim 2, further comprising a step of electrically connecting the second data line to the first data line. A substrate,
A first active matrix circuit formed on the first surface of the substrate;
A second active matrix circuit including an organic transistor formed on a second surface opposite to the first surface of the substrate;
An active matrix substrate comprising: The first active matrix circuit includes a first scan line and a first data line intersecting the first scan line,
The second active matrix circuit has a second scan line and a second data line intersecting the second scan line,
The active matrix substrate according to claim 6, wherein an arrangement pitch of the second scanning lines is an integral multiple of an arrangement pitch of the first scanning lines. The first active matrix circuit includes a first scan line and a first data line intersecting the first scan line,
The second active matrix circuit has a second scan line and a second data line intersecting the second scan line,
The active matrix substrate according to claim 6, wherein an arrangement pitch of the second data lines is an integral multiple of an arrangement pitch of the first data lines.   9. The active matrix substrate according to claim 7, wherein the second scan line is electrically connected to the first scan line. 10.   The active matrix substrate according to claim 7 or 8, wherein the second data line is electrically connected to the first data line.   11. The first active matrix circuit is configured to include any of an amorphous silicon transistor, a polysilicon transistor, an oxide transistor, and an organic transistor. Active matrix substrate.   The at least one of an optical sensor, a magnetic sensor, a temperature sensor, a pressure sensor, and a memory circuit is formed in the second active matrix circuit, according to any one of claims 6 to 11. Active matrix substrate.   An electro-optical device comprising the active matrix substrate according to claim 6.   14. The electro-optical device according to claim 13, wherein any one of a liquid crystal display, an electrophoretic display, an organic EL display, an inorganic EL display, and an electrochromic display is formed on the first active matrix circuit. .   14. The electro-optical device according to claim 13, wherein any one of a liquid crystal display, an electrophoretic display, an organic EL display, an inorganic EL display, and an electrochromic display is formed on the second active matrix circuit. .   An electronic apparatus comprising the electro-optical device according to claim 13.

Images