JP2011209539A - Active matrix-type driving substrate, method for manufacturing the same, and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active matrix-type driving substrate which reduces power consumption and improves a yield when applied to a display device such as an electronic paper, and to provide a method for manufacturing the substrate.SOLUTION: The active matrix-type driving substrate 50 includes a thin-film transistor 10 and a storage capacitor 20 which are provided on a conductive base material 1 having a first insulating film 2 on a surface thereof, and a pixel electrode 30 covering the thin-film transistor 10 and the storage capacitor 20 via second insulating films 16 and 17, wherein the storage capacitor 20 is a laminate composed of a first electrode 21, a dielectric film 22, and a second electrode 23 connected to source/drain electrodes 14 and 15 of the thin-film transistor 10. The conductive base material 1 and the first electrode 21 are connected through an opening 4 of the first insulating film 2. The second insulating films (16 and 17) have at least an interlayer insulating film 17. Preferably, the conductive base material 1 is a metal base material, and the first insulating film 2 is a planarizing film which reduces surface roughness of the metal base material 1.

Description

  The present invention relates to an active matrix drive substrate, a manufacturing method thereof, and a display device including the drive substrate. More specifically, the present invention relates to an active matrix driving substrate that can reduce power consumption and improve yield when applied to a display device such as electronic paper, a manufacturing method thereof, and the like.

  The active matrix type drive substrate is used as a drive substrate for turning on / off the display pixel in a liquid crystal display device, an organic EL device, electronic paper, and the like. For example, an active matrix driving substrate used for electronic paper or the like usually includes a pixel electrode, a thin film transistor that controls ON / OFF of the pixel electrode, a storage capacitor, and an X wiring (scanning line) that supplies a voltage signal to the thin film transistor. (Also referred to as a gate line) and Y wiring (data line) and a common line for supplying current to the storage capacitor are wired vertically and horizontally.

  FIG. 22 is a schematic cross-sectional view showing an example of unit pixels 103 of a general active matrix driving substrate 100 used for electronic paper. FIG. 23 shows the unit pixels 103 shown in FIG. 22 arranged in a matrix. 2 is a schematic plan view mainly showing a pattern of a first electrode 121 for the active matrix drive substrate 100. FIG. 22 and 23 are examples in which a metal substrate is used as the base substrate 101, and a flattening layer 102 for smoothing the surface irregularities of the metal substrate is provided on the surface of the metal substrate. Yes. As shown in FIG. 22, the active matrix driving substrate 100 includes a thin film transistor 110 and a storage capacitor 120 provided in-plane (in the same plane), and a pixel electrode 130 provided so as to cover them. For example, microcapsule electrophoretic electronic paper is configured such that a microcapsule layer, a transparent electrode layer, and a transparent substrate are arranged in this order on a pixel electrode 130 of an active matrix drive substrate 100.

  Specifically, as shown in FIG. 22, the thin film transistor 110 includes a gate electrode 111, a gate insulating film 112, a semiconductor film 113, source / drain electrodes 114 and 115, and a protective film 116 in a predetermined pattern on the planarization layer 102. They are provided in order. The storage capacitor 120 is formed on the planarization layer 102 by a first electrode 121 (formed simultaneously with the same material as the gate electrode 111), a dielectric film 122 (formed simultaneously with the same material as the gate insulating film 112), and a second electrode 123 (formed simultaneously. The source / drain electrodes 114 and 115 are formed of the same material at the same time) in a predetermined pattern in that order. The same protective film 116 as the thin film transistor 110 is provided over the storage capacitor 120. The pixel electrode 130 is provided so as to cover the thin film transistor 110 and the storage capacitor 120 with an interlayer insulating film 117 for reducing the parasitic capacitance interposed therebetween. The pixel electrode 130 is connected to the second electrode 123 through an opening 131 that penetrates the protective film 116 and the interlayer insulating film 117, and the second electrode 123 is connected to the source / drain electrodes 114 and 115 of the thin film transistor 110. ing.

  As shown in FIG. 23, such an active matrix driving substrate 100 includes a thin film transistor 110, a gate line 141 that supplies a voltage signal to the gate electrode 111 of the thin film transistor 110, and a voltage signal to the source / drain electrodes 114 and 115 of the thin film transistor 110. And a data line 142 for supplying. The data line 142 is orthogonal to the gate line 141 and is wired vertically and horizontally so as to surround the unit pixel 103 together with the gate line 141. On the other hand, the second electrode 123 of the storage capacitor 120 is connected to the source / drain electrodes 114 and 115 of the thin film transistor 110, but the first electrode 121 is connected to the storage capacitor 120 of the adjacent unit pixel 103 as shown in FIG. The first electrode 141 is connected by a common line 143.

  Patent Document 1 is an invention relating to an organic EL device, and FIG. 5 and paragraph 0083 of the same document describe a storage capacitor Cs composed of a metal substrate, a part of a second insulating film, and a capacitor electrode. Yes. This storage capacitor has a problem in that a part of the second insulating film is provided on the metal substrate, so that the metal substrate and the capacitor electrode are short-circuited due to the surface roughness of the metal substrate, thereby causing an insulation failure. .

JP 2007-310352 A

  In the above-described general active matrix driving substrate 100, as shown in FIG. 23, the common line 143 intersects with the data line 142 (depending on the wiring direction of the common line). For this reason, there is a problem in that the parasitic capacitance of the data line 142 (or the gate line 141) increases and the power consumption increases. Further, there is a problem that an insulation failure is likely to occur at the intersection and the yield is likely to decrease.

  In addition, in an active matrix type driving substrate such as electronic paper where transparency of the substrate is not required as an essential component, it is preferable to use a metal substrate having good heat resistance and flexibility as the base substrate. Has a rough surface compared to a glass substrate or a plastic substrate, and a short circuit is likely to occur.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an active matrix capable of reducing power consumption and improving yield when applied to a display device such as electronic paper. A mold driving substrate and a manufacturing method thereof are provided. Another object of the present invention is to provide a display device including such an active matrix driving substrate.

  In order to solve the above problems, an active matrix drive substrate according to the present invention includes a thin film transistor and a storage capacitor provided on a conductive base material having a first insulating film on the surface, and the thin film transistor and the storage capacitor are connected to a second insulating film. And a storage substrate, the storage capacitor being a laminate of a first electrode, a dielectric film, and a second electrode connected to a source / drain electrode of the thin film transistor, The substrate and the first electrode are connected to each other through an opening of the first insulating film.

  According to this invention, since the conductive base material and the first electrode constituting the storage capacitor are electrically connected, the conductive base material can supply current to the first electrode. As a result, it is not necessary to provide a common line that intersects the data line or the gate line as in the conventional case, and therefore, the parasitic capacitance of the data line or the gate line does not increase, and the power consumption can be reduced. In addition, since there is no intersection between the data line or gate line and the common line, insulation failure is unlikely to occur, and a reduction in yield can be prevented. Therefore, when the active matrix driving substrate of the present invention is applied to a display device such as electronic paper, power consumption can be reduced and yield can be improved.

  In the active matrix drive substrate according to the present invention, the second insulating film has at least an interlayer insulating film.

  According to the present invention, the interlayer insulating film included in the second insulating film is effective in reducing the parasitic capacitance between the thin film transistor and each electrode of the storage capacitor and the pixel electrode.

  In the active matrix drive substrate according to the present invention, the conductive base material is a metal base material, and the first insulating film is a planarizing film that reduces the surface roughness of the metal base material.

  According to the present invention, since a metal substrate having excellent heat resistance is used, no problem occurs even if heat treatment is applied during the production of a thin film transistor, for example. Further, although the surface of the metal substrate may be relatively rough, in the present invention, since the planarizing film for reducing the surface roughness is provided on the metal substrate, the electrode provided on the planarizing film Can prevent short circuit.

  The active matrix drive substrate according to the present invention is configured such that the second electrode is not provided above the opening in a sectional view.

  According to this invention, since the second electrode is not provided above the opening, it is possible to prevent a short circuit problem due to the surface roughness of the conductive base material in the opening.

  In order to solve the above problems, a display device according to the present invention includes an active matrix driving substrate according to the present invention, a display layer disposed on a pixel electrode included in the active matrix driving substrate, and the display layer. A counter electrode disposed on the counter electrode, and a transparent substrate disposed on the counter electrode.

  According to the present invention, since the active matrix drive substrate capable of reducing power consumption and improving yield can be provided, a display device with energy saving and good quality stability can be provided. It is particularly effective as flexible electronic paper.

In order to solve the above problems, a method of manufacturing an active matrix driving substrate according to the present invention includes a thin film transistor, a stacked body of a first electrode, a dielectric film, and a second electrode connected to a source / drain electrode of the thin film transistor. A method of manufacturing an active matrix drive substrate comprising a certain storage capacitor and a pixel electrode that covers the thin film transistor and the storage capacitor via a second insulating film,
A step of preparing a conductive base material having a first insulating film on the surface; a step of forming an opening of a predetermined pattern in the first insulating film; and the thin film transistor and the storage capacitor on the first insulating film And forming a second insulating film covering the thin film transistor and the storage capacitor, and forming the second insulating film covering the thin film transistor and the storage capacitor. Forming a predetermined pattern of an opening in a second insulating film on the electrode; and forming a pixel electrode connected to the second electrode through the opening so as to cover the thin film transistor and the storage capacitor. It is characterized by having.

  According to this invention, since the conductive base material and the first electrode constituting the storage capacitor are electrically connected, the conductive base material can supply current to the first electrode. As a result, it is not necessary to provide a common line that intersects the data line or the gate line as in the conventional case, and therefore, the parasitic capacitance of the data line or the gate line does not increase, and the power consumption can be reduced. In addition, since the manufactured active matrix drive substrate does not have an intersection between the data line or the gate line and the common line, it is difficult for an insulation failure to occur and a reduction in yield can be prevented. Therefore, when the active matrix drive substrate manufactured according to the present invention is applied to a display device such as electronic paper, power consumption can be reduced and yield can be improved.

  According to the active matrix drive substrate and the manufacturing method thereof according to the present invention, the conductive base material is responsible for supplying current to the first electrode by electrically connecting the conductive base material and the first electrode constituting the storage capacitor. Therefore, it is not necessary to provide a common line that intersects with the data line or the gate line as in the conventional case. As a result, the parasitic capacitance of the data line or the gate line does not increase, and the power consumption can be reduced. In addition, since the manufactured active matrix drive substrate does not have an intersection between the data line or the gate line and the common line, it is difficult for an insulation failure to occur and a reduction in yield can be prevented. Therefore, when the active matrix drive substrate manufactured according to the present invention is applied to a display device such as electronic paper, power consumption can be reduced and yield can be improved.

  According to the display device of the present invention, since the active matrix drive substrate that can reduce power consumption and improve the yield is provided, it is possible to provide a display device with energy saving and good quality stability. It is particularly effective as flexible electronic paper.

It is a typical sectional view showing an example of an active matrix type drive substrate (including a bottom gate top contact type TFT) concerning the present invention. FIG. 4 is a process diagram (part 1) illustrating a method of manufacturing the active matrix drive substrate illustrated in FIG. 1; FIG. 6 is a process diagram (part 2) illustrating the method for manufacturing the active matrix drive substrate illustrated in FIG. 1; FIG. 8 is a process diagram (part 3) illustrating the method for manufacturing the active matrix drive substrate illustrated in FIG. 1; FIG. 8 is a process diagram (part 4) illustrating a method of manufacturing the active matrix drive substrate shown in FIG. 1; FIG. 10 is a process diagram (part 5) illustrating the method for manufacturing the active matrix drive substrate illustrated in FIG. 1; FIG. 10 is a process diagram (part 6) illustrating a method for manufacturing the active matrix drive substrate illustrated in FIG. 1; FIG. 11 is a process diagram (part 7) illustrating the method for manufacturing the active matrix drive substrate illustrated in FIG. 1; FIG. 8 is a process diagram (part 8) illustrating the method for manufacturing the active matrix drive substrate illustrated in FIG. 1; It is typical sectional drawing which shows an example of the active matrix type drive board | substrate (including top gate bottom contact type TFT) concerning this invention. It is typical sectional drawing which shows an example of the thin-film transistor which concerns on this invention. FIG. 11 is a process diagram (part 1) illustrating a method for manufacturing the active matrix drive substrate illustrated in FIG. 10; FIG. 11 is a process diagram (part 2) illustrating the method for manufacturing the active matrix drive substrate illustrated in FIG. 10; FIG. 11 is a process diagram (part 3) illustrating the method for manufacturing the active matrix drive substrate illustrated in FIG. 10; FIG. 11 is a process diagram (part 4) illustrating the manufacturing method of the active matrix drive substrate shown in FIG. 10; FIG. 11 is a process diagram (part 5) illustrating the manufacturing method of the active matrix drive substrate illustrated in FIG. 10; FIG. 11 is a process diagram (part 6) illustrating the manufacturing method of the active matrix drive substrate shown in FIG. 10; FIG. 11 is a process diagram (part 7) illustrating the method for manufacturing the active matrix drive substrate illustrated in FIG. 10; FIG. 11 is a process diagram (part 8) illustrating a method for manufacturing the active matrix drive substrate illustrated in FIG. 10; It is typical sectional drawing which shows an example of the active matrix type drive board | substrate (including bottom gate bottom contact type TFT) concerning this invention. It is a typical sectional view showing an example of an active matrix type drive substrate (including a top gate top contact type TFT) concerning the present invention. It is typical sectional drawing which shows an example of the thin-film transistor which concerns on this invention. It is typical sectional drawing which shows an example of the display apparatus which concerns on this invention. It is a typical sectional view showing an example of a unit pixel of a general active matrix type drive board used for electronic paper. FIG. 23 is a schematic plan view mainly showing a pattern of a first electrode in the active matrix driving substrate in which unit pixels shown in FIG. 22 are arranged in a matrix.

  Hereinafter, an active matrix drive substrate, a manufacturing method thereof, and a display device according to the present invention will be described in detail with reference to the drawings. The present invention can be modified in various ways as long as it has the technical features, and is not limited to the embodiments specifically shown below.

[Active Matrix Drive Substrate and Manufacturing Method Thereof]
(Basic configuration)
The active matrix drive substrate 50 (hereinafter abbreviated as “AM-type drive substrate 50”) according to the present invention has a first insulating film 2 on its surface as shown in FIGS. It includes a thin film transistor 10 and a storage capacitor 20 provided on the conductive substrate 1, and a pixel electrode 30 that covers the thin film transistor 10 and the storage capacitor 20 via a second insulating film 18. In the present invention, the storage capacitor 20 is a laminate of the first electrode 21, the dielectric film 22, and the second electrode 23 connected to the source / drain electrodes 14 and 15 of the thin film transistor 10. The first electrode 21 constituting the storage capacitor 20 is connected to the opening 5 of the first insulating film 2 (also referred to as the first opening 5).

  As shown in FIGS. 2 to 9 and FIGS. 11 to 18, the manufacturing method of the AM type driving substrate 50 according to the present invention includes the thin film transistor 10, the first electrode 21, the dielectric film 22, the source of the thin film transistor 10. An AM type driving substrate including a storage capacitor 20 that is a laminate of the second electrode 23 connected to the drain electrodes 14 and 15, and a pixel electrode 30 that covers the thin film transistor 10 and the storage capacitor 20 via the second insulating film 18. 50. And the process includes the steps of preparing a conductive substrate 1 having a first insulating film 2 on the surface, forming a predetermined pattern of openings (first openings 5) in the first insulating film 2, A step of forming the thin film transistor 10 and the storage capacitor 20 in the in-plane direction on the insulating film 2 and connecting the conductive substrate 1 and the first electrode 21 constituting the storage capacitor 20 through the first opening 5; A step of forming a second insulating film 18 covering the capacitor 10 and the storage capacitor 20 and forming an opening (second opening 32) having a predetermined pattern in the second insulating film 18 on the second electrode 23; And a step of forming the pixel electrode 30 connected to the second electrode 23 through the portion 32 so as to cover the thin film transistor 10 and the storage capacitor 20.

  In such an AM type driving substrate 50 and the manufacturing method thereof, the conductive base material 1 and the first electrode 21 constituting the storage capacitor 20 are electrically connected. Therefore, the conductive base material 1 can supply current to the first electrode 21. As a result, there is no need to provide a common line that intersects the data line or the gate line as in the conventional case, and therefore, the parasitic capacitance of the data line 42 or the gate line 41 does not increase, and the power consumption can be reduced. . Further, as shown in FIG. 6 and the like, the manufactured AM type driving substrate 50 does not have a crossing portion between the data line 42 or the gate line 41 and the common line (in this application, the conductive base material 1 takes charge). . Therefore, it is difficult for insulation failure to occur, and a decrease in yield can be prevented. Therefore, if the AM type driving substrate 50 manufactured by the present invention is applied to a display device such as electronic paper, the power consumption can be reduced and the yield can be improved.

[First Embodiment]
First, a manufacturing process of the AM type driving substrate 50A having the bottom gate top contact type thin film transistor shown in FIG. 1 will be described with reference to FIGS. A bottom gate top contact type thin film transistor 10 constituting an AM type driving substrate 50A shown in FIG. 1 includes a gate electrode 11 having a predetermined pattern provided on a first insulating film 2 on a conductive substrate 1, and a gate electrode 11 A gate insulating film 12 covering the gate electrode, a semiconductor film 13 having a predetermined pattern provided on the gate insulating film 12 and above the gate electrode 11, and a central portion (channel region) on the semiconductor film 13 being opened and separated. It has the source / drain electrodes 14 and 15 provided and a protective film 16 covering the whole.

(Preparation process of conductive substrate)
As a base material, a conductive base material 1 having a first insulating film 2 on its surface is prepared. The conductive substrate 1 may be a substrate made entirely of a conductive material, or may be a substrate in which a conductive material is provided at least on the surface on which the first insulating film 2 is formed. In short, the conductive substrate 1 is electrically connected to a first electrode 21 described later through the first opening 5 of the first insulating film 2 provided on the surface, and is provided in a matrix. Any device capable of supplying a current to each of the first electrodes 21 formed may be used.

  Preferred examples of the conductive substrate 1 composed entirely of a conductive material include metal substrates, and specific examples include foil or film metal substrates such as stainless steel and copper. The metal substrate has high heat resistance, and has an advantage that no problem occurs even if heat treatment is applied in the manufacturing process of the thin film transistor 10 described later. As the conductive substrate 1 provided with a conductive material at least on the surface on which the first insulating film 2 is formed, for example, on a non-conductive substrate such as a plastic substrate, a glass substrate or a ceramic substrate, Examples thereof include those having a conductive layer provided as a face film or in a predetermined pattern. The conductive layer in this case is not particularly limited as long as a current can be supplied to the first electrode 21 constituting the storage capacitor 20, but for example, a metal layer such as a copper layer, an aluminum layer, a gold layer, or a silver layer may be used. Can be mentioned. Such a conductive layer may be provided on the entire surface of the substrate or may be provided in a predetermined pattern, and is usually provided with a thickness of about 0.01 to 100 μm. It is preferable.

  The conductive substrate 1 preferably has flexibility. By using such a conductive base material 1, a flexible AM-type driving substrate 50 </ b> A can be manufactured, and a display device such as flexible electronic paper can be manufactured. The thickness of the conductive substrate 1 having flexibility is not particularly limited, but is usually 0.01 to 1 mm in the case of a metal substrate, and preferably 0.05 to 0.1 mm in the case of a stainless steel substrate, for example. . On the other hand, in the case of the conductive base material 1 provided with the conductive layer, the flexibility varies depending on the type of the base material.

  The first insulating film 2 is provided on the entire surface of the conductive base material 1 or a necessary location. The conductive base material 1 on which the first insulating film 2 is provided in advance may be obtained, but usually, for example, on the entire surface of one surface of the metal base material (the surface on the side where the thin film transistor 0 and the storage capacitor 20 are provided). It is provided by coating. The first insulating film 2 preferably functions as an insulating film and functions as a planarizing film. When a metal substrate is used as the conductive substrate 1, the surface is rough and most of the arithmetic average roughness Ra is 10 nm to 100 nm, but there are many protrusions and scratches of about 1 to 10 μm. Therefore, it is preferable that the first insulating film 2 is used as a planarizing film to reduce the surface roughness of the metal substrate from the viewpoint of preventing a short circuit with an electrode provided on the planarizing film. The surface roughness can be measured with a stylus type surface roughness meter, an AFM (atomic force microscope), or the like.

  As the 1st insulating film 2, the film | membrane which consists of insulating resins, such as a polyimide resin and an acrylic resin, can be mentioned preferably. The thickness is set mainly in consideration of insulation and flatness, but is usually 5 to 10 μm.

  A base film may be provided on the first insulating film 2 as necessary. For example, an adhesion film, a stress relaxation film, a buffer film (thermal buffer film), or the like may be provided. As an example, a compound film made of chromium oxide, titanium oxide, aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, or the like is preferably used. These films may be provided as a single layer or two or more layers may be laminated depending on the function or purpose. Such a base film can be formed by various methods such as various vapor deposition methods, DC sputtering method, RF magnetron sputtering method, plasma CVD method, etc., but in practice, a preferable method according to the material constituting the film is adopted. Is done.

(Formation process of the first opening)
Next, as shown in FIGS. 2A1 and 2A2, openings (first openings 5) having a predetermined pattern are formed in the first insulating film 2. The first opening 5 is formed by first providing a photosensitive resist film on the first insulating film 2, exposing and developing, and forming an etching mask having a predetermined pattern in which the first opening 5 is formed. To do. Next, the first opening 5 is formed in the first insulating film 2 using the etching solution for the first insulating film 2. Various types of photosensitive resist films can be used. Although the etching solution varies depending on the type of the first insulating film 2, a hydrazine-based etchant can be used when the first insulating film 2 is, for example, a polyimide film. The formed first opening 5 functions as a contact hole for connecting the first electrode 21 and the conductive base material 1 formed thereafter.

(Thin film transistor and storage capacitor formation process)
Next, as shown in FIGS. 3B1 and 3B2 to FIGS. 7F1 and 7F2, the thin film transistor 10 and the storage capacitor 20 are formed on the first insulating film 2 in the in-plane direction. Further, in the formation process, the conductive substrate 1 and the first electrode 21 constituting the storage capacitor 20 are connected by the first opening 5. Hereinafter, the steps of forming the thin film transistor 10 and the storage capacitor 20 will be sequentially described.

  First, as shown in FIGS. 3B1 and 3B2, the gate electrode 11, the gate line 41, and the first electrode 21 are formed on the first insulating film 2. The gate electrode 11 is a component of the thin film transistor 10, and the first electrode 21 is a component of the storage capacitor 20. The gate line 41 is a wiring for supplying a voltage signal to the gate electrode 11, and is connected to an external circuit through a flexible printed wiring board (not shown) or the like at the periphery of the AM type driving substrate 50A. The gate electrode 11, the gate line 41, and the first electrode 21 (hereinafter also referred to as “gate electrode or the like”) are formed by forming a metal film on the entire surface covering the first insulating film 2 and the first opening 5, and then Each pattern is formed in a predetermined pattern. Therefore, they are formed of the same material at the same time.

Examples of the material for forming the gate electrode include metal materials such as Al, W, Ta, Mo, Cr, Ti, Cu, Au, AlMg, MoW, and MoNb, ITO (indium tin oxide), indium oxide, and IZO (indium). Zinc oxide), transparent conductive materials such as SnO ₂ and ZnO can be preferably mentioned. Note that a transparent conductive polymer such as polyaniline, polyacetylene, a polyalkylthiophene derivative, or a polysilane derivative may be used as long as it has desired conductivity.

  For forming the gate electrode and the like, film forming means and patterning means corresponding to the kind of forming material and the heat resistance of the conductive base material 1 are applied. For example, when a gate electrode or the like is formed of a metal material or a transparent conductive material, a sputtering method or various CVD methods can be applied as a film forming unit, and photolithography can be applied as a patterning unit, but low temperature film formation is required. In this case, a sputtering method or a plasma CVD method capable of forming at a low temperature can be preferably applied as the film forming means. In the case of forming a gate electrode or the like with a conductive polymer, a vacuum deposition method, a pattern printing method, or the like can be applied as a film forming unit, and photolithography can be applied as a patterning unit. The thickness of the gate electrode or the like is usually about 0.05 to 0.1 μm.

  Next, as shown in FIGS. 4C1 and 4C, insulating films 12 and 22 are formed on the entire surface covering the gate electrode 11, the gate line 41, and the first electrode 21. The insulating films 12 and 22 function as the gate insulating film 12 in the thin film transistor 10 and function as the dielectric film 22 in the storage capacitor 20. The gate line 41 formed as described above functions as a normal insulating film. The insulating films 12 and 22 may be made of various materials as long as they have high insulating properties and a relatively high dielectric constant and are suitable as the gate insulating film of the thin film transistor 10 and the dielectric film of the storage capacitor 20. it can. For example, silicon oxides such as silicon oxide, silicon nitride, and silicon oxynitride, nitrides, oxynitrides, and the like can be preferably exemplified. In addition, at least one or more of yttrium oxide, aluminum oxide, hafnium oxide, zirconium oxide, titanium oxide, tantalum oxide, niobium oxide, scandium oxide, and barium strontium titanate can be given.

  For the formation of the insulating films 12 and 22, film forming means and patterning means corresponding to the type of insulating film material and the heat resistance of the conductive base material 1 are applied. For example, when the insulating films 12 and 22 are formed of silicon oxide, nitride, oxynitride or the like, a DC sputtering method, an RF magnetron sputtering method, a plasma CVD method, or the like can be applied as a film forming means, and a patterning means Photolithography can be applied. The thicknesses 12 and 22 are usually about 0.1 to 0.3 μm. Further, the insulating films 12 and 22 may be applied and formed using a known coating type insulating film forming material, and the thickness in this case is usually about 0.2 to 1.0 μm.

  The insulating films 12 and 22 are preferably provided so as to cover the entire surface, but may be formed in a pattern at a necessary place. When the insulating films 12 and 22 are provided on the entire surface, patterning is performed by photolithography. At this time, an extraction electrode portion for connection to a flexible printed wiring board (not shown) is opened as a fifth opening portion 6. The fifth opening 6 is provided at the peripheral edge of the AM type drive substrate 50A, and the end of the gate line 41 is exposed through the fifth opening 6 so that it can be connected to the flexible printed wiring board. The exposed gate line 41 is connected to an external circuit through a flexible printed wiring board.

  Next, as shown in FIGS. 5D1 and 5D2, a semiconductor film 13 having a predetermined pattern is formed over the gate insulating film 12. The semiconductor film 13 may be an amorphous silicon semiconductor film, a polysilicon type semiconductor film, or an oxide semiconductor film. In the following, the case where an oxide semiconductor film (reference numeral 13 is used) that can be preferably applied to either an inverted staggered type or a forward staggered type will be described.

As the oxide semiconductor film 13, various oxides having semiconductor characteristics can be used, and preferably an IMZO semiconductor film can be used. The oxide constituting the IMZO semiconductor film 13 is an amorphous oxide containing InMZnO (M is at least one of Ga, Al, and Fe) as a main constituent element. In particular, an InGaZnO-based amorphous oxide in which M is Ga is preferable. In this case, the ratio of In: Ga: Zn is preferably 1: 1: m (m <6). When Mg is further included, it is preferable that the ratio of In: Ga: Zn _1-x Mg _x is 1: 1: m (m <6) and 0 <x ≦ 1. The composition ratio is measured by a fluorescent X-ray (XRF) apparatus. The InGaZnO-based amorphous oxide exhibits an amorphous phase in a wide composition range of In, Ga, and Zn. The composition range stably showing the amorphous phase in this ternary system is In _x Ga _y Zn _z O _{(3x / 2 + 3y / 2 + z)} and the ratio x / y is in the range of 0.4 to 1.4, and the ratio It can be expressed such that z / y is in the range of 0.2-12. In addition, crystalline is shown with a composition close to ZnO and a composition close to In ₂ O ₃ . Amorphous oxides include In _x Ga _1-x oxide (0 ≦ x ≦ 1), In _x Zn _1-x oxide (0.2 ≦ x ≦ 1), In _x Sn _1-x oxide ( Any amorphous oxide selected from 0.8 ≦ x ≦ 1) and In _x (Zn, Sn) _1-x oxide (0.15 ≦ x ≦ 1) may be used.

  In the present invention, an InGaZnO-based semiconductor film (IGZO semiconductor film) can be preferably exemplified. In addition, the IGZO semiconductor film may be added with Al, Fe, Sn or the like as a constituent element, if necessary.

  Whether the IMZO semiconductor film 13 is amorphous or not is a clear indication of the presence of crystalline when X-ray diffraction is performed on the IMZO semiconductor film to be measured at a low incident angle of about 0.5 °. It can be confirmed that a diffraction peak is not detected, that is, a so-called halo pattern is seen. Such a halo pattern is also observed in the IMZO semiconductor film in a microcrystalline state. Therefore, the IMZO semiconductor film 13 includes such an IMZO semiconductor film in the microcrystalline state.

  The IMZO semiconductor film 13 is formed by a film forming unit and a patterning unit corresponding to the type of semiconductor material and the heat resistance of the conductive substrate 1. For example, a DC sputtering method, an RF magnetron sputtering method, a plasma CVD method, or the like can be applied as a film forming unit, and photolithography can be applied as a patterning unit. Note that as a sputtering target in the case of forming a film by sputtering, it is preferable to use a sputtering target adjusted so as to obtain a desired film formation composition under predetermined sputtering conditions. Usually, a sputtering target having the same composition as the target film-forming composition is preferably used. The thickness of the IMZO semiconductor film 13 is not generally specified because it is arbitrarily designed depending on the deposition conditions, but it is usually preferably in the range of 10 to 150 nm, and preferably in the range of 15 to 50 nm. More preferred.

  In the step of forming the IMZO semiconductor film 13 having a predetermined pattern, (i) the IMZO semiconductor film 13 is formed on the entire surface covering the gate insulating film 12, and then the IMZO semiconductor film 13 formed on the entire surface is patterned using a photoresist ( Exposure, development, etching) and processing into a predetermined pattern, or (ii) forming an IMZO semiconductor film 13 over the entire surface covering the gate insulating film 12, and further forming a passivation film (over the entire surface covering the IMZO semiconductor film 13) Then, the passivation film is patterned into a predetermined pattern (exposure, development, etching) by a photoresist method, and the IMZO semiconductor film 13 is patterned (etched) using the patterned passivation film as a mask. Any of the methods of processing into a predetermined pattern can be applied.

The passivation film used here can be formed by forming a passivation film material such as liquid silica (SiO ₂ hydrate) or polyimide resin by a coating method, and then patterning using a resist. Alternatively, a passivation film material having photosensitivity may be formed by a coating method, followed by exposure and development to form a passivation film having a predetermined pattern. The thickness of such a passivation film is usually about 0.1 to 3 μm.

  Next, as shown in FIGS. 6E1 and E2, source / drain electrodes 14 and 15, a second electrode 23, and a data line 42 are provided. The source / drain electrodes 14 and 15 are provided in a predetermined pattern on the IMZO semiconductor film 13, the second electrode 23 is provided above the dielectric film 22 facing the first electrode 21, and the data line 42 is a source or drain It is provided in a manner to be connected to the drain electrode 14. These are provided simultaneously with the same material. In FIG. 6 (E1), the data line 42 and the source electrode 14 are connected, and the source electrode 15 and the second electrode 23 are connected. The data line 42 is provided around the pixel so as to be orthogonal to the gate line 41.

The electrode material constituting the source / drain electrodes 14 and 15, the second electrode 23 and the data line 42 (these are referred to as “source / drain electrodes”) is not particularly limited as long as it is a metal wiring material. Transparent conductive films such as metal materials such as W, Ta, Mo, Cr, Ti, Cu, Au, AlMg, MoW, MoNb, ITO (indium tin oxide), indium oxide, IZO (indium zinc oxide), SnO ₂ , ZnO Can be mentioned. Further, a conductive polymer such as polyaniline, polyacetylene, polyalkylthiophene derivative, polysilane derivative, or the like may be used as long as it has desired conductivity. When an IGZO semiconductor film is formed as the semiconductor film 13, it is selected in consideration of ohmic contact with the IGZO semiconductor film 13, and for example, a metal film such as Ti, Ag, Mo, and MoW is preferable.

  For forming the source / drain electrodes and the like, film forming means and patterning means corresponding to the type of electrode material and the heat resistance of the conductive substrate 1 are applied. For example, when a source / drain electrode is formed with a metal film or a transparent conductive film, a DC sputtering method, an RF magnetron sputtering method, a plasma CVD method, etc. can be applied as a film forming means, and photolithography can be applied as a patterning means. . The thickness of the source / drain electrodes and the like is usually about 0.1 to 0.3 μm.

  When a passivation film (not shown) is formed on the IMZO semiconductor film 13 (not shown), a contact hole is formed in the passivation film other than the channel region of the IMZO semiconductor film 13 prior to the formation of the source / drain electrodes and the like. May be formed. Such a passivation film is provided to form the source electrode connection portion and the drain electrode connection portion in the contact hole portion while protecting the channel region of the IMZO semiconductor film 13. After providing a passivation film having a contact hole, an activation process is usually performed. By this activation treatment, the conductivity of the IMZO semiconductor film 13 exposed at the contact hole portion can be increased to form a source electrode connection portion and a drain electrode connection portion. When the source / drain electrodes 14 and 15 are patterned on the source electrode connecting portion and the drain electrode connecting portion with enhanced conductivity, ohmic resistance of the source / drain electrodes 14 and 15 with respect to the source electrode connecting portion and the drain electrode connecting portion, respectively. Can be reduced.

  In the present invention, the second electrode 23 is not provided above the first opening 5 in a sectional view. Therefore, even when the conductive base material 1 (metal base material or the like) having a large surface roughness is applied, the first electrode 21 takes over the surface roughness of the conductive base material 1 in the first opening 5. As a result, it is possible to prevent a problem that the withstand voltage of the first insulating film 2 on the first electrode 21 is lowered and a short circuit is likely to occur. In this case, the upper side in the cross-sectional view means that it does not extend at least on the peripheral edge of the first opening 5, and preferably the second electrode 23 is 10 μm or more outside the periphery of the first opening 5. It is preferable to be provided.

  The second electrode 23 is provided continuously with the source electrode 14 or the drain electrode 15, and the second electrode 23 is connected to the pixel electrode 30 through a second opening 32 of the second insulating film 18 described later. . That is, it also has a function of transmitting or relaying an ON / OFF voltage signal from the source electrode 14 or the drain electrode 15 to the image electrode.

  The data line 42 extends to the peripheral edge of the conductive base material 1, and at the peripheral edge, the data line 42 serves as an extraction electrode for connection to a flexible printed wiring board (not shown). The extraction electrode is exposed at an opening (not shown), and is connected to an external circuit via a flexible printed wiring board.

(Process for forming second insulating film and second opening)
Next, as shown in FIGS. 7F1 and 7F2 and FIGS. 8G1 and 8G2, the second insulating film 18 covering the thin film transistor 10 and the storage capacitor 20 is formed, and the second insulating film 18 on the second electrode 23 is formed. 2 Openings (second openings 32) having a predetermined pattern are formed in the insulating film 18.

  The second insulating film 18 has at least an interlayer insulating film 17. The interlayer insulating film 17 is parasitic between each electrode (source / drain electrodes 14 and 15, second electrode 23, gate line 41, data line 42, etc.) of the thin film transistor 10 and the storage capacitor 20 and a pixel electrode 30 described later. Effective for capacity reduction. Here, “at least” means that another insulating film may be provided as necessary. Specifically, a protective film 16 for protecting the thin film transistor 10 may be mentioned. Such a protective film 16 is preferably provided particularly when an oxide semiconductor film is employed as the semiconductor film 13. Therefore, the second insulating film 18 includes at least the interlayer insulating film 17 and may further include another insulating film such as the protective film 16. Here, an example in which a protective film 16 is provided will be described as illustrated.

  First, as shown in FIGS. 7F1 and 7F2, a protective film 16 is formed so as to cover the thin film transistor 10 and the source / drain electrodes of the storage capacitor 20. The protective film 16 is a film that acts to protect the thin film transistor 10. By providing the protective film 16, the operation of the thin film transistor 10 is not affected by the atmosphere (for example, moisture, vacuum, temperature) and can be stably operated without causing an unstable operation due to a change in the atmosphere. Is obtained. Therefore, the protective film 16 is provided so as to cover the whole after the basic structure of the thin film transistor 10 is formed.

Examples of the material for forming the protective film 16 include metal oxides, metal nitrides, metal carbides, and metal oxynitrides containing at least one metal element. As the metal, silicon, aluminum and the like are preferable. Specifically, examples of the metal oxide include SiO ₂ and Al ₂ O ₃ , and examples of the metal nitride include Si _x N _y and AlN. Examples of the metal carbide include SiC and TiC, and examples of the metal oxynitride include SiON and SiAlON. Among these, a protective film made of SiO ₂ is preferable.

  Examples of the method for forming the protective film 16 include sputtering, resistance heating vapor deposition, laser vapor deposition, electron beam vapor deposition, and chemical vapor deposition (CVD). The thickness of the protective film 16 is not generally specified because it is arbitrarily designed depending on the film formation conditions, but it is usually preferably in the range of 10 nm to 200 nm, and preferably in the range of 50 nm to 150 nm. Is more preferable.

After the protective film 16 is formed, heat treatment is preferably performed as necessary depending on the type of the semiconductor film 13. For example, when the IMZO semiconductor film 13 is formed as the semiconductor film 13, the semiconductor characteristics of the IMZO semiconductor film 13 can be improved by heat treatment. For example, it is possible to increase the ON / OFF ratio of drain current to at least 10 ⁵ or more. Note that this heat treatment may be performed in a mode in which a passivation film (not shown) is provided on the IMZO semiconductor film 13.

  The reason why the heat treatment is effective when the IMZO semiconductor film 13 is provided is as follows. That is, in the formation process of the source / drain electrodes 14 and 15 on the IMZO semiconductor film 13, the IMZO is generated by plasma during sputtering or plasma CVD, plasma during sputtering or plasma CVD in the formation process of the protective film 16, and the like. The semiconductor film 13 is greatly damaged. Specifically, a defect is generated in the oxide of the IMZO semiconductor film 13 due to plasma in particular to make it conductive (high electrical conductivity), and the semiconductor characteristics are deteriorated. Therefore, by performing heat treatment after forming the protective film 16 on the IMZO semiconductor film 13, the characteristics of the IMZO semiconductor film 13 in which the semiconductor characteristics are significantly reduced due to the conductor can be improved. The reason why such an effect arises is that, when the above-mentioned specific type of protective film 16 is laminated on the IMZO semiconductor film 13 and subjected to heat treatment, atomic hydrogen is generated during the heat treatment, and the atomic hydrogen is This is considered to be because the defects generated in the IMZO semiconductor film 13 are terminated. It is presumed that the semiconductor characteristics of the IMZO semiconductor film 13 made conductive by plasma damage have been recovered by the termination of the defective portion.

  In this case, the heat treatment temperature may be in the range of 100 to 500 ° C. When a heat-resistant substrate is used like a metal substrate, there is no problem even at a higher temperature of 250 to 500 ° C., preferably 250 to 350 ° C. However, when a conductive substrate 1 including a resin layer is used. The range of 100 ° C to 200 ° C is preferred. The heat treatment is preferably performed in any one of a nitrogen gas atmosphere, an oxidizing gas atmosphere, and a water vapor atmosphere. In the heat treatment in an oxidizing gas atmosphere, the atmospheric gas pressure is preferably in the range of 0.01 atmospheric pressure to 1 atmospheric pressure. In the heat treatment in a steam atmosphere, the steam pressure is preferably in the range of 1 to 20 atmospheres, and particularly preferably a high-pressure steam atmosphere of 5 to 15 atmospheres. Heat treatment in a high-pressure steam atmosphere is preferable because the semiconductor properties of the IMZO semiconductor film 13 can be improved and the interface state and insulating properties of the gate insulating film 14 can be improved.

  Next, after the protective film 16 is provided on the entire surface and subjected to heat treatment or the like as necessary, a second opening 32 having a predetermined pattern is formed in the protective film 16 as shown in FIGS. 7 (F1) and (F2). To do. The second opening 32 is a portion that connects the second electrode 23 and a pixel electrode 30 described later. In the illustrated example, the second opening 32 is provided at a position farthest from the first opening 5 in the pixel diagonal. The formation of the second opening 32 can be performed by general photolithography. The protective film 16 is generally patterned after being provided on the entire surface, but may be selectively provided at a necessary location.

  Next, as shown in FIGS. 8G1 and 8G2, an interlayer insulating film 17 is formed so as to cover the protective film 16 provided with the second opening 32. The interlayer insulating film 17 is effective for reducing the parasitic capacitance between the thin film transistor 10, the gate line and the source line, and the pixel electrode. The material for forming the interlayer insulating film 17 is not particularly limited, and various kinds of materials can be used. Can be used. As an example, a transparent acrylate resin (manufactured by Nippon Steel Chemical Co., Ltd., V259) can be used. As a method of forming the interlayer insulating film 17, various coating methods such as spin coating and die coating are preferably applied, and the thickness of the formed interlayer insulating film 17 is relatively 4 to 50 μm from the viewpoint of reducing parasitic capacitance. Thickness is preferable, and 2 to 5 μm is more preferable.

  Next, after the interlayer insulating film 17 is provided over the entire surface, a fourth opening 34 having a predetermined pattern is formed in the interlayer insulating film 17 as shown in FIGS. The fourth opening 34 is provided at the same location as the second opening 32. The location is a location where the second electrode 23 and a pixel electrode 30 described later are connected. The fourth opening 34 can be formed by general photolithography. The interlayer insulating film 17 is usually patterned after being provided on the entire surface, like the protective film 16, but may be selectively provided at a necessary location.

  Thus, in the illustrated example, the second insulating film 18 including the protective film 16 and the interlayer insulating film 17 has an opening (the second opening 32 and the fourth opening 34) that connects to the pixel electrode 30. Form with.

(Pixel electrode formation process)
Next, as shown in FIGS. 9H1 and 9H, the pixel electrode 30 connected to the second electrode 23 through the openings (the second opening 32 and the fourth opening 34) is held with the thin film transistor 10. The capacitor 20 is formed so as to cover it. The pixel electrode 30 is usually provided on the entire surface and then patterned by photolithography. However, the pixel electrode 30 may be selectively provided at a necessary location. Examples of the material for forming the pixel electrode 30 include Al, Ti, Ag, ITO (indium tin oxide), and IZO (indium zinc oxide). As a method for forming the pixel electrode 30, a DC magnetron sputtering method or the like is preferably applied, and the thickness of the formed pixel electrode 30 is preferably 0.1 to 0.3 μm.

[Second Embodiment]
Next, a manufacturing process of the AM type driving substrate 50B having the top gate bottom contact type thin film transistor shown in FIG. 10 will be described with reference to FIGS. The top gate / bottom contact type thin film transistor 10 constituting the AM type driving substrate 50B shown in FIG. 10 opens and separates a predetermined region (region to be a channel region) on the first insulating film 2 on the conductive base material 1. A predetermined pattern of source / drain electrodes 14 and 15 and a semiconductor film of a predetermined pattern provided to fill the predetermined region between the source / drain electrodes 14 and 15 and to straddle the source / drain electrodes 14 and 15. 13, a gate insulating film 12 provided so as to cover them (source / drain electrodes 14, 15 and semiconductor film 13), and a gate electrode 11 provided on the gate insulating film 12 and above the semiconductor film 13. And have. Since the components of the AM type drive board 50B of the second embodiment are basically the same as those of the first embodiment, the same reference numerals are used, and description thereof will be omitted as occasion demands.

  The conductive substrate 1 and the first insulating film 2 provided on the conductive substrate 1 are prepared in the same manner as in the first embodiment. Others are the same as in the first embodiment.

  Next, as shown in FIGS. 11A1 and 11A2, openings (first openings 5) having a predetermined pattern are formed in the first insulating film 2. Others are the same as in the first embodiment.

  Next, as shown in FIGS. 12B1 and 12B to 15E1 and E2, the thin film transistor 10 and the storage capacitor 20 are formed in the in-plane direction on the first insulating film 2, and the formation process thereof. Thus, the conductive substrate 1 and the first electrode 21 constituting the storage capacitor 20 are connected by the first opening 5.

  Specifically, as shown in FIGS. 12B1 and 12B, source / drain electrodes 14 and 15, a data line 42, and a second electrode 23 are formed on the first insulating film 2. The source / drain electrodes 14 and 15 are components of the thin film transistor 10, and the second electrode 23 is a component of the storage capacitor 20. The data line 42 is a wiring for supplying a voltage signal to the source / drain electrodes 14, 15, and is connected to an external circuit via a flexible printed wiring board (not shown) or the like at the periphery of the AM type driving substrate 50 B. . The source / drain electrodes 14 and 15, the data line 42, and the second electrode 23 (hereinafter also referred to as “source / drain electrodes”) are formed by depositing a metal film on the entire surface covering the first insulating film 2 and the first opening 5. A film is formed and then patterned to form a predetermined pattern. Therefore, they are formed of the same material at the same time. The material for forming the source / drain electrodes, the forming means, and the thickness thereof are the same as those in the first embodiment.

  The second electrode 23 is provided on the first insulating film 2 and is not provided above the first opening 5 in a sectional view. Therefore, even when the conductive base material 1 (metal base material or the like) having a large surface roughness is applied, the conductive base material is provided through the first insulating film 2 that preferably acts as a planarizing film. Problems such as a short circuit based on the surface roughness of 1 can be prevented. In this case, the upper side in the cross-sectional view means that it does not extend at least on the peripheral edge of the first opening 5, and preferably the second electrode 23 is 10 μm or more outside the periphery of the first opening 5. It is preferable to be provided.

  The second electrode 23 is provided continuously with the source electrode 14 or the drain electrode 15, and the second electrode 23 is connected to the pixel electrode 30 through a second opening 32 of the second insulating film 18 described later. Connecting. That is, it also has a function of transmitting or relaying an ON / OFF voltage signal from the source electrode 14 or the drain electrode 15 to the image electrode.

  Next, as shown in FIGS. 13C1 and 13C, a semiconductor film 13 having a predetermined pattern is formed across the source / drain electrodes 14 and 15. The forming material, forming means, thickness, and the like of the semiconductor film 13 are the same as those in the first embodiment.

  Next, as shown in FIGS. 14D1 and 14D, insulating films 12 and 22 are formed on the entire surface covering the semiconductor film 13, the source / drain electrodes 14 and 15, the second electrode 23, and the first opening 5. Thereafter, the insulating film on the first opening 5 is removed to form the fourth opening 34, and the portion different from the fourth opening 34 and where the first electrode 21 described later is not provided. The insulating film 22 is removed and a third opening 33 is formed. The insulating films 12 and 22 function as the gate insulating film 12 in the thin film transistor 10 and function as the dielectric film 22 in the storage capacitor 20. Further, it functions as a normal insulating film on the data line 42. The forming material, forming means and thickness of the insulating films 12 and 22 are the same as those in the first embodiment.

  As in the first embodiment, the insulating films 12 and 22 are preferably provided so as to cover the entire surface, but may be formed in a pattern at a necessary portion. When the insulating films 12 and 22 are provided on the entire surface, patterning is performed by photolithography. At this time, an extraction electrode portion for connection with a flexible printed wiring board (not shown) is opened as an opening portion (not shown). The opening is provided at the peripheral edge of the AM type driving substrate 50, and the end of the data line 42 is exposed at the opening so that it can be connected to the flexible printed wiring board. The exposed data line 42 is connected to an external circuit through a flexible printed wiring board.

  The gate insulating film 12 provided on the semiconductor film 13 also functions as a protective film for the semiconductor film 13 as in the first embodiment. Therefore, the gate insulating film 12 is preferably made of a material that can be used in combination with the function as the protective film of the first embodiment. Examples of such a gate insulating film 12 include metal oxides, metal nitrides, metal carbides, metal oxynitrides, and the like, which can be cited as materials for forming the protective film 16. Further, as in the case of the first embodiment, it is preferable to perform heat treatment as necessary. As a result, the semiconductor characteristics of the semiconductor film 13 can be improved as in the case of the first embodiment.

  Next, as shown in FIGS. 15E1 and E2, the gate electrode 11, the gate line 41, and the first electrode 21 are formed on the insulating films 12 and 22. The gate electrode 11 is a component of the thin film transistor 10, and the first electrode 21 is a component of the storage capacitor 20. The gate line 41 is a wiring for supplying a voltage signal to the gate electrode 11, and is connected to an external circuit through a flexible printed wiring board (not shown) or the like at the periphery of the AM type driving substrate 50A. The gate electrode 11, the gate line 41, and the first electrode 21 (hereinafter also referred to as “gate electrode or the like”) are formed on the entire surface covering the insulating films 12 and 22 and the first opening 5 and the fourth opening 34. Are formed and then patterned to form a predetermined pattern. Therefore, they are formed of the same material at the same time.

  The first electrode 21 is electrically connected to the conductive substrate 1 through the first opening 5 and the fourth opening 34. Further, the first electrode 21 is not provided on the third opening 33. Specifically, it is preferable that the first electrode 21 is provided at least 10 μm outside the periphery of the third opening 33. The formation material, the formation means, the thickness, and the like of the gate electrode are the same as those in the first embodiment.

  Next, as shown in FIGS. 16 (F1) and (F2), a second insulating film 18 covering the thin film transistor 10 and the storage capacitor 20 is formed, and then, as shown in FIGS. 17 (G1) and (G2), the insulating film A predetermined pattern of openings (second openings 32) is formed on the 22 third openings 33.

  The second insulating film 18 has at least the interlayer insulating film 17. The protective film as in the first embodiment is not necessarily provided because the gate insulating film 12 can be substituted. The interlayer insulating film 17 is effective in reducing the parasitic capacitance between each electrode (the gate electrode 11, the first electrode 21, the gate line 41, etc.) of the thin film transistor 10 and the storage capacitor 20 and the pixel electrode 30 described later. The material for forming the interlayer insulating film 17, the forming means and its thickness, and the opening means for the second opening 32 to the interlayer insulating film 17 are the same as in the first embodiment.

  Next, as shown in FIGS. 18H1 and 18H, the pixel electrode 30 connected to the second electrode 23 through the second opening 32 of the interlayer insulating film 17 and the third opening 33 of the insulating film 22 is formed. The thin film transistor 10 and the storage capacitor 20 are formed so as to cover. The pixel electrode 30 is usually provided on the entire surface and then patterned by photolithography. However, the pixel electrode 30 may be selectively provided at a necessary location. The formation material, the formation means, the thickness, and the like of the pixel electrode 30 are the same as those in the first embodiment.

[Third Embodiment]
In the AM type drive substrate 50C having the bottom gate bottom contact type thin film transistor, the formation order of the semiconductor film 13, the source / drain electrodes 14, 15 and the second electrode 23 is only reverse to that in the first embodiment. Other than that, the second embodiment is the same as the first embodiment. Therefore, it can be manufactured in the same manner as in the first embodiment. A bottom gate bottom contact type thin film transistor 10 constituting the AM type driving substrate 50C of FIG. 19 includes a gate electrode 11 having a predetermined pattern provided on the first insulating film 2 on the conductive substrate 1, and a gate electrode 11 formed thereon. A gate insulating film 12 provided so as to cover, source / drain electrodes 14 and 15 provided with a central portion (channel region) on the gate insulating film 12 opened and spaced apart; and on the gate insulating film 12. A semiconductor film 13 having a predetermined pattern is provided above the gate electrode 11 so as to straddle between the source / drain electrodes 14 and 15, and a protective film 16 covering the whole.

[Fourth Embodiment]
In the AM type driving substrate 50D having a top gate top contact type thin film transistor, the formation order of the semiconductor film 13, the source / drain electrodes 14, 15 and the second electrode 23 is merely the reverse of the case of the second embodiment. Other than that, the second embodiment is the same as the second embodiment. Therefore, it can be manufactured in the same manner as in the second embodiment. A top gate top contact type thin film transistor 10 constituting the AM type driving substrate 50D of FIG. 20 includes a semiconductor film 13 having a predetermined pattern provided on the first insulating film 2 on the conductive substrate 1, and Provided so as to cover the semiconductor film 13 and the source / drain electrodes 14, 15, and the semiconductor film 13 and the source / drain electrodes 14, 15, which are spaced apart from each other by opening a predetermined center region (region to be a channel region). A gate insulating film 12 and a gate electrode 11 provided on the gate insulating film 12 and above the semiconductor film 13 are provided.

  As described above, as shown in the first to fourth embodiments, according to the manufacturing method of the AM type driving substrates 50A to 50D according to the present invention, the conductive substrate 1 and the first electrode 21 constituting the storage capacitor 20 are electrically connected. It connected so that the electrically conductive base material 1 might carry out the electric current supply to the 1st electrode 21. Therefore, it is not necessary to provide a common line that intersects with the data line 42 or the gate line 41 as in the prior art, and as a result, the parasitic capacitance of the data line 42 or the gate line 41 does not increase and the power consumption is reduced. Can do. In addition, since the AM type drive substrate 50 manufactured by this manufacturing method does not have the intersection between the data line 42 or the gate line 41 and the common line, it is difficult for insulation failure to occur and the yield can be prevented from being lowered. Therefore, if the AM type drive substrates 50A to 50D manufactured in the present invention are applied to a display device such as electronic paper, the power consumption can be reduced and the yield can be improved.

[Display device]
As shown in FIG. 21, a display device 80 according to the present invention includes an AM driving substrate 50 according to the present invention, a display layer 81 disposed on the pixel electrode 30 of the AM driving substrate 50, It has a counter electrode 82 disposed on the display layer 81 and a transparent substrate 83 disposed on the counter electrode 82. Since the display device having such a configuration includes the AM type drive substrate 50 that can reduce power consumption and improve yield, it can be an energy saving and stable display device. It is particularly effective as flexible electronic paper. Here, the AM-type drive substrate 50 has been described, and will be omitted.

  As the display layer 81, for example, a display layer of an electronic paper or an organic EL layer can be preferably exemplified. In particular, as a display layer of electronic paper, a microcapsule electrophoresis layer used in a microcapsule electrophoresis method, a twist ball layer used in a twist ball method, an air layer having charged particles used in a toner display method, and the like can be given. . The display layer supplies an N / OFF signal from the thin film transistor 10 and the storage capacitor 20 from the pixel electrode 30 to turn on / off the display layer 81 corresponding to each pixel and display an image. This display layer may be provided on the counter electrode 82 described later and bonded to the AM type driving substrate 50, or may be provided on the AM type driving substrate 50 and bonded to the counter electrode 82. It may be.

  As the counter electrode 82, for example, a transparent conductive film such as ITO or IZO can be preferably cited. As a film forming means for the counter electrode 82, a DC sputtering method, an RF magnetron sputtering method, or the like can be applied. The thickness is usually about 0.05 to 0.3 μm. The counter electrode 82 is usually provided on a transparent base material 83 to be described later. The counter electrode 82 may be bonded to the AM type driving substrate 50 with the display layer 81 provided thereon, or may be bonded to the AM type driving substrate 50 provided with the display layer 81. .

  Examples of the transparent substrate 83 include glass, quartz, polyethylene, polypropylene, polyethylene terephthalate, polymethacrylate, polymethyl methacrylate, polymethyl acrylate, polyester, polycarbonate, and the like. The thickness of the transparent substrate 83 differs depending on whether or not the obtained display device 80 is flexible, and is not particularly limited. For example, when a flexible electronic paper is used, a plastic substrate having a thickness of 5 to 300 μm. Is preferably used.

  According to such a display device 80, since the active matrix drive substrate capable of reducing power consumption and improving yield can be provided, a display device with energy saving and good quality stability can be provided. It is particularly effective as flexible electronic paper.

DESCRIPTION OF SYMBOLS 1 Conductive base material 2 1st insulating film 3 Unit pixel 5 Opening part (1st opening part)
6 opening (5th opening)
DESCRIPTION OF SYMBOLS 10 Thin-film transistor 11 Gate electrode 12 Gate insulating film (insulating film)
DESCRIPTION OF SYMBOLS 13 Semiconductor film | membrane 14,15 Source / drain electrode 16 Protective film 17 Interlayer insulating film 18 2nd insulating film 19 Extraction electrode 20 Retention electrode 21 1st electrode 22 Dielectric film 23 2nd electrode 30 Pixel electrode 32 Opening part (2nd opening) Part)
33 opening (third opening)
34 opening (fourth opening)
41 gate line 42 data line 50 active matrix type drive substrate 50A bottom gate top contact type 50B top gate bottom contact type 50C bottom gate bottom contact type 50D top gate top contact type 80 display device (electronic paper)
81 Display layer (microcapsule electrophoresis layer)
82 Counter electrode 83 Transparent substrate

DESCRIPTION OF SYMBOLS 100 Active matrix drive substrate 101 Metal base material 102 Planarizing layer 103 Unit pixel 110 Thin film transistor 111 Gate electrode 112 Gate insulating film 113 Semiconductor film 114,115 Source / drain electrode 116 Protective film 117 Interlayer insulating film 120 Retention capacity 121 First electrode 122 dielectric film 123 second electrode 130 pixel electrode 131 opening 141 gate line 142 data line 143 common line

Claims (6)

  A thin film transistor and a storage capacitor provided on a conductive base material having a first insulating film on a surface; and a pixel electrode that covers the thin film transistor and the storage capacitor through a second insulating film, wherein the storage capacitor is a first electrode And a dielectric substrate and a second substrate connected to the source / drain electrodes of the thin film transistor, wherein the conductive base material and the first electrode are openings of the first insulating film. An active matrix drive substrate characterized by being connected.   The active matrix driving substrate according to claim 1, wherein the second insulating film includes at least an interlayer insulating film.   3. The active matrix drive substrate according to claim 1, wherein the conductive base material is a metal base material, and the first insulating film is a planarizing film that reduces the surface roughness of the metal base material.   4. The active matrix drive substrate according to claim 1, wherein the second electrode is not provided above the opening in a cross-sectional view. 5.   5. The active matrix drive substrate according to claim 1, a display layer disposed on a pixel electrode included in the active matrix drive substrate, a counter electrode disposed on the display layer, And a transparent substrate disposed on the counter electrode. A storage capacitor that is a laminate of a thin film transistor, a first electrode, a dielectric film, and a second electrode connected to a source / drain electrode of the thin film transistor, and a pixel that covers the thin film transistor and the storage capacitor via a second insulating film A method of manufacturing an active matrix drive substrate comprising electrodes,
Preparing a conductive substrate having a first insulating film on the surface;
Forming an opening of a predetermined pattern in the first insulating film;
Forming the thin film transistor and the storage capacitor on the first insulating film in an in-plane direction, and connecting the conductive substrate and the first electrode constituting the storage capacitor through the opening;
Forming a second insulating film covering the thin film transistor and the storage capacitor, and forming an opening of a predetermined pattern in the second insulating film on the second electrode;
Forming a pixel electrode connected to the second electrode through the opening so as to cover the thin film transistor and the storage capacitor;
A method for manufacturing an active matrix drive substrate, comprising:

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