JP2002353235A - Active matrix substrate, display using the same, and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active matrix substrate of which the cost can be reduced and waste in members and energy can be eliminated by forming a plurality of value-added thin film transistors(TFT) or semiconductor circuit element groups on a first substrate, and partially transferring them to needed portions of a second substrate, and to provide a display using the same and a manufacturing method. SOLUTION: The first substrate 31 comprises the plurality of TFTs or the semiconductor circuit elements thereon, and a plurality of the TFTs or a portion of the circuit element groups are transferred to the second substrate having a thin film patterning thereon, which is the active matrix substrate. The plurality of the TFTs or a portion of the circuit element groups may be transferred to the second substrate directly, or the plurality of TFTs or a portion of the circuit element groups may be transferred to the second substrate through a third substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix substrate used for a display device such as a liquid crystal display and an organic electroluminescence (EL) display and an imaging device such as a line sensor and an area sensor.

[0002]

2. Description of the Related Art Conventionally, a method of manufacturing an active matrix substrate used for a display device such as a liquid crystal display or an organic electroluminescence (EL) display and an imaging device such as a line sensor or an area sensor requires a semiconductor manufacturing technology and equipment. It was improved to be able to handle large translucent substrates.

Hereinafter, a conventional method for manufacturing an active matrix substrate will be described.

FIG. 8 shows a sectional structure of a thin film transistor (TFT) which is one unit of a conventional active matrix substrate. 8, a gate electrode 2 is formed on a surface of a glass substrate 1 by, for example, a sputtering apparatus.
It is formed with a laminated structure of i and Al. A gate insulating film 3 is formed on the surface thereof, an amorphous silicon 4 having intrinsic characteristics (do not intentionally add impurities) is formed thereon, and a P-doped amorphous silicon 5 is formed on the surface thereof. Are formed. The gate insulating film 3, the amorphous silicon 4 and the amorphous silicon 5 doped with P
It is formed continuously by a plasma CVD apparatus. Source / drain electrodes 6 are formed on the surface. Source·
As an example, the drain electrode 6 is formed in a laminated structure of Ti and Al by a sputtering device. Each thin film layer is patterned by a resist pattern by photolithography and dry or wet etching and TF
Create a T shape.

FIG. 9 is a plan view of one pixel unit when a conventional active matrix substrate is applied to a liquid crystal display. The TFT portion is the same as the cross-sectional view described above. Reference numerals 8 denote storage capacitors formed at overlapping portions of the pixel electrodes 7 and the gate lines 21. FIG. 10 shows an equivalent circuit of FIG. FIG.
Reference numeral 61 denotes a source wiring, Vs denotes a signal voltage applied to the source wiring, and Vg denotes a scanning pulse applied to the gate wiring.

[0006]

However, in the configuration of the conventional example, the area occupied by the TFTs (portions 2, 4, 5, and 6) is very small, as can be seen from FIG. Other than the above, the same film forming process and patterning process are performed, but all are removed. Equipment for TFT fabrication,
The clean rooms and prime movers where they are installed are very expensive. Further, labor costs are added, and as a result, the cost of the active matrix substrate is very high. In addition, most of the thin film formed for TFT fabrication is removed and discarded, which wastes global resources. In addition, a lot of energy and etching gas and chemicals are used for the discarded portion. And had a great impact on the global environment.

[0007] In order to solve the above-mentioned conventional problems, the present invention is to form a plurality of high value-added TFTs and semiconductor circuits on a first substrate and transfer them to a required portion of a second substrate, thereby forming an active matrix substrate. It is an object of the present invention to provide an active matrix substrate in which the cost of the device is reduced, waste of members and energy is reduced, a display device using the same, and a method of manufacturing the same.

[0008]

In order to achieve this object, an active matrix substrate according to the present invention comprises a plurality of thin film transistors or circuit element groups formed on a first substrate, and the plurality of thin film transistor or circuit element groups. And a patterned thin film on the second substrate.

It is preferable that the patterned thin film on the second substrate comprises a conductor and an insulator.

It is preferable that the first substrate is at least one selected from a glass substrate, a quartz substrate, and a silicon single crystal substrate.

It is preferable that the second substrate is a glass substrate or a plastic substrate.

It is preferable that a metal wiring pattern and a resistance pattern which generates heat when energized are provided at a predetermined location on the second substrate.

A thin film transistor or a circuit element group transferred to the second substrate; an insulating film on the second substrate and the thin film transistor or the circuit element group; and a contact formed on a predetermined portion of the insulating film. It is preferable to include a hole and a metal wiring.

Next, in a first method of manufacturing an active matrix substrate according to the present invention, a part of the plurality of thin film transistors or circuit element groups is formed from a first substrate on which a plurality of thin film transistors or circuit element groups are formed by a second method. It is characterized in that it is moved onto a substrate.

Next, in a second method of manufacturing an active matrix substrate according to the present invention, a part of the plurality of thin film transistors or circuit element groups is converted from a first substrate on which a plurality of thin film transistors or circuit element groups are formed to a third method. It is characterized in that it is moved onto a second substrate via the substrate.

Next, a third method of manufacturing an active matrix substrate according to the present invention comprises the steps of: separating a plurality of thin film transistors or circuit element groups formed on the first substrate into predetermined units; Characterized by being moved to a substrate.

In the first to third methods, it is preferable that the first substrate is a glass substrate, a quartz substrate, or a silicon single crystal substrate.

In the above method, the second substrate is preferably a glass substrate or a plastic substrate.

In the above method, the plurality of thin film transistors or circuit element groups formed on the first substrate are transferred by the first adhesive resin on the third substrate, and the second group formed on the second substrate is transferred. It is preferable that a part of the plurality of thin film transistors or circuit element groups on the third substrate be transferred onto the second substrate by an adhesive resin.

In the above method, the third substrate is preferably made of a plastic film.

In the above method, it is preferable that the first adhesive resin is thermoplastic and the second adhesive resin is thermosetting.

In the above method, the third substrate preferably has a function of passing a liquid or a gas.

In the above method, it is preferable that a metal wiring pattern and a resistance pattern which generates heat when energized are provided on a predetermined position on the second substrate.

In the above method, the thin film transistor or the circuit element group transferred to the second substrate, the insulating film on the second substrate and the thin film transistor or the circuit element group, and the insulating film formed on a predetermined portion of the insulating film may be formed. It is preferable that the contact hole and the metal wiring are formed.

Next, the display device of the present invention comprises a plurality of thin film transistors or circuit element groups formed on a first substrate, and a second substrate on which a part of the plurality of thin film transistor or circuit element groups is mounted. And a patterned thin film on the second substrate.

As described above, there is a configuration in which TFTs and circuit element groups are formed on the first substrate at high density, and these TFTs and circuit element groups are individually transferred to the second substrate. I have.

[0027]

(Embodiment 1) Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a method for manufacturing the first substrate and the second substrate will be described. FIG. 1 shows a TFT formed on a first substrate. TFT
The structure is the same as that of FIG. 8, except that a sacrificial layer 32 and an undercoat layer 33 are formed on a substrate 31, and a passivation layer 34 is formed on the TFT. For example,
Amorphous silicon, a metal material or a layer modified in advance by ion implantation or the like is used for the sacrifice layer 32, silicon oxide is used for the undercoat layer 33, and silicon nitride is used for the passivation layer. Reference numeral 35 denotes a thin film removed portion provided for separating and separating each TFT.

FIG. 2 is a plan view of the substrate shown in FIG. 1. On the first substrate, a number of TFT units 36-1, 2, 3 are formed within the allowable range of the process rules.

FIG. 3 is a plan view of the second substrate, in which a wiring pattern is formed in advance. In this example,
The source wiring 37 and a part 39 of the gate wiring are formed in advance. Numeral 38 is a heat generating portion described later.

Next, the TFT is transferred from the first substrate to the second substrate.
Will be described with reference to the process step diagrams of FIGS.

In FIG. 4A, reference numeral 41 denotes a third substrate. In this example, a plastic substrate is used. 42 is a thermoplastic adhesive layer. The third substrate is provided with a hole 43 through which an etching gas or a chemical solution can enter. The TFT on the second substrate of FIG. 1 is heated and pressed against the third substrate to bond the second substrate and the third substrate (FIG. 4 (b)). I do. When the sacrificial layer 32 is made of amorphous silicon, a hydrogen radical, a radical such as NF ₃ or SF ₆ , or a mixed solution of hydrofluoric acid and nitric acid is used. By the above processing, the TFT can be peeled off from the first substrate (FIG. 4).
(C)).

Next, a thermosetting adhesive 45 is applied to a predetermined area on the second substrate 44 in FIG. 5A, and the second substrate and the third substrate are pressed and heated. Thereafter, when the two substrates are separated, the TFT is transferred to the second substrate (FIG. 5).
(b)). Heating may be performed on the entire surface of the substrate, or heat may be generated by applying a current to the resistor portion 38 shown in FIG.

Next, after the passivation layer 51 is formed again and the contact holes 52 are formed (FIG. 6A), a metal wiring 53 pattern connecting the wirings is formed (FIG. 6).
(b)). The step of forming the passivation layer 51 can be omitted by forming the passivation layer on the second substrate in advance. Further, a passivation layer may be formed after a metal pattern connecting the wirings is formed first. In that case, a contact hole is formed in the passivation layer only in the drain portion of the TFT,
A pixel electrode may be formed. Further, the material of the second substrate is not limited to glass or plastic as long as the surface is smooth.

(Embodiment 2) As a second embodiment, an example of transferring a circuit element group will be described. FIG. 7 shows a circuit element group 72 formed on a Si single crystal wafer. Driver IC, Controller I
C, an integrated circuit such as a RAM or a CPU. These circuit element groups are transferred to the second substrate 44 by, for example, the method of FIG. As an example, in the case of a display device, it is preferable to form a pixel portion as in the first embodiment, and transfer these circuit element groups to the periphery. The TFT and the circuit element group may be a low-temperature polysilicon TFT on a glass substrate as a constituent element. By combining the active matrix substrate having the above configuration with an element for controlling light intensity such as a liquid crystal cell or an organic EL, a system display can be easily and at low cost. Applications of such a system display include a mobile phone and a PDA (personal digital assi
stance) for portable information terminals.
Lightweight and thinner. Further, the present invention can be applied to a sheet-shaped personal computer, a liquid crystal television, a display device for a notebook computer, a liquid crystal monitor, and the like. In each case, a thinner and more sophisticated display device can be realized. Further, in the case of a display device using a reflection type liquid crystal display or an organic EL, since the circuit element group can be formed on the back surface of the second substrate by the above-described method, higher functions can be achieved. For example, on the surface of the second substrate, only TFTs for driving pixels and wiring are formed,
When a driver IC, a controller IC, a RAM, and the like are formed on the back surface, a display device that is thin and realizes an ultimate narrow frame can be manufactured.

As described above, according to the embodiment of the present invention, an infinite number of TFTs and semiconductor circuits having a high added value are formed on the first substrate and transferred to necessary parts of the second substrate, thereby enabling active circuits. The cost of the matrix substrate can be significantly reduced, and the waste of members and energy can be significantly reduced. In addition, the first substrate and the third substrate can be reused, which also contributes greatly to cost reduction and global environment. Furthermore, the size of the first substrate and the size of the second substrate are different, for example, when the first substrate is manufactured on an existing production line, and the production line of the second substrate with few steps is used on a new production line. The realization of a large-screen display device is also possible with a small capital investment and a small number of personnel.

[0036]

As described above, the present invention provides a low-cost active matrix by transferring TFTs or circuit elements formed on a first substrate at high density to a second substrate. Substrate can be realized. In addition, limited resources can be used effectively. By using this, a high display device or an imaging device can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a first substrate according to Embodiment 1 of the present invention.

FIG. 2 is a plan view of a first substrate according to the first embodiment of the present invention.

FIG. 3 is a plan view of a second substrate according to the first embodiment of the present invention.

FIGS. 4A to 4C are cross-sectional views illustrating a manufacturing process of the active matrix substrate according to the first embodiment of the present invention.

FIGS. 5A and 5B are cross-sectional views showing the same manufacturing process.

FIGS. 6A and 6B are cross-sectional views showing the same manufacturing process.

FIG. 7 is a plan view showing a circuit element group on a Si wafer according to a second embodiment of the present invention.

FIG. 8 is a cross-sectional view of a conventional active matrix substrate.

FIG. 9 is a plan view of a conventional active matrix substrate.

FIG. 10 is an equivalent circuit diagram of the active matrix substrate of FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 31 First substrate 32 Sacrificial layer 33 Undercoat layer 34 Passivation layer 41 Third substrate 42 Thermoplastic adhesive 43 Hole through which etching gas or chemical solution passes 44 Second substrate 45 Thermosetting adhesive 51 Passivation layer 52 contact hole 53 metal wiring 71 Si single crystal substrate 72 circuit element group

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09F 9/30 310 G09F 9/30 338 338 348A 348 H01L 27/12 B H01L 27/12 29/78 627D 29 / 786 626C F-term (Reference) 2H090 JB02 JB03 JB04 2H092 GA29 JA24 MA12 NA29 PA01 5C094 AA43 AA44 AA45 BA03 CA19 DA15 FB01 5F110 AA30 BB01 CC07 DD01 DD02 DD12 DD13 DD17 DD25 EE03 GG04 FF30 GG03 HK22 HK25 HK33 HK35 QQ16

Claims (18)

[Claims] 1. A plurality of thin film transistors or circuit element groups formed on a first substrate, a second substrate for mounting a part of the plurality of thin film transistors or circuit element groups, and the second substrate An active matrix substrate comprising: a patterned thin film thereon; 2. The active matrix substrate according to claim 1, wherein the patterned thin film on the second substrate comprises a conductor and an insulator. 3. The active matrix substrate according to claim 1, wherein the first substrate is at least one selected from a glass substrate, a quartz substrate, and a silicon single crystal substrate. 4. The active matrix substrate according to claim 1, wherein the second substrate is a glass substrate or a plastic substrate. 5. The active matrix substrate according to claim 1, wherein a metal wiring pattern and a resistance pattern that generates heat when energized are provided at predetermined locations on the second substrate. 6. A thin film transistor or circuit element group transferred to a second substrate, an insulating film on the second substrate and the thin film transistor or circuit element group, and a contact hole formed in a predetermined portion of the insulating film. 6. The active matrix substrate according to claim 1, comprising a metal wiring. 7. A method of manufacturing an active matrix substrate, comprising: moving a part of the plurality of thin film transistors or circuit element groups onto a second substrate from a first substrate on which a plurality of thin film transistors or circuit element groups are formed. Method. 8. A method according to claim 1, wherein a portion of the plurality of thin film transistors or circuit element groups is moved from a first substrate on which a plurality of thin film transistors or circuit element groups are formed to a second substrate via a third substrate. Of manufacturing an active matrix substrate. 9. A method for manufacturing an active matrix substrate, wherein a plurality of thin film transistors or circuit element groups formed on a first substrate can be peeled off in predetermined units and then moved to a second substrate. Method. 10. The method for manufacturing an active matrix substrate according to claim 7, wherein the first substrate is a glass substrate, a quartz substrate, or a silicon single crystal substrate. 11. The method for manufacturing an active matrix substrate according to claim 7, wherein the second substrate is a glass substrate or a plastic substrate. 12. A plurality of thin film transistors or circuit element groups formed on a first substrate are transferred by a first adhesive resin on a third substrate, and are transferred by a second adhesive resin formed on a second substrate. 9. The method according to claim 8, wherein a part of the plurality of thin film transistors or circuit element groups on the third substrate is transferred onto the second substrate.
3. The method for manufacturing an active matrix substrate according to 1. 13. The method according to claim 8, wherein the third substrate is made of a plastic film. 14. The method according to claim 12, wherein the first adhesive resin is thermoplastic and the second adhesive resin is thermosetting. 15. The method for manufacturing an active matrix substrate according to claim 8, wherein the third substrate has a function of passing a liquid or a gas. 16. The method for manufacturing an active matrix substrate according to claim 7, wherein a metal wiring pattern and a resistance pattern which generates heat by energization are provided at predetermined locations on the second substrate. 17. A thin film transistor or circuit element group transferred to a second substrate, an insulating film on the second substrate and the thin film transistor or circuit element group, and a contact hole formed in a predetermined portion of the insulating film. 10. The method of manufacturing an active matrix substrate according to claim 7, comprising: a metal wiring. 18. A plurality of thin film transistors or circuit element groups formed on a first substrate, a second substrate on which a part of the plurality of thin film transistors or circuit element groups are mounted, and A display device using an active matrix substrate composed of a patterned thin film.