JP2001305582A - Liquid crystal display with built-in peripheral drive circuit - Google Patents

Abstract

An object of the present invention is to increase the degree of freedom in circuit layout and increase the functionality and performance of a circuit without increasing the cost. SOLUTION: A first wiring formed by processing a first metal thin film forming a gate electrode 5 of a thin film transistor, and a second wiring formed by processing a second metal thin film contacting source / drain regions 6, 7 are formed. A second driving circuit is provided by using a second wiring, a third wiring 13 formed by processing a third metal thin film used as a reflective pixel electrode, and using the first, second, and third wirings. As a result, the circuit layout becomes easy, and a high-performance and high-performance liquid crystal display device with a built-in peripheral driving circuit can be obtained without increasing the cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type liquid crystal display device with a built-in peripheral driving circuit.

[0002]

2. Description of the Related Art A conventional reflection type liquid crystal display device with a built-in peripheral driving circuit will be described below.

FIGS. 5 and 6 are partial schematic cross-sectional views showing the main parts of a conventional reflection type liquid crystal display device with a built-in peripheral drive circuit. FIG. 5 shows a peripheral drive circuit unit, which is of a P type and an N type.
(CMOS configuration) thin film transistor. FIG. 6 shows a screen unit. 5 and 6, 1
Is a glass substrate, 2 is an insulating film, 3 is a polysilicon layer, 4 is a gate insulating film, 5 is a gate electrode (first wiring), 6 is a source region, 7 Is a drain region, 8 is an interlayer insulating film, 9 and 10
Is the source / drain contact
This is a drain electrode (second wiring), and one thin film transistor is composed of 3 to 10. Reference numeral 11 denotes an acrylic planarizing film (often about 3 μm in thickness), and reference numeral 12 denotes a reflective pixel electrode. 14 is a liquid crystal, 1
5 is an alignment film, 16 is a transparent electrode, and 17 is a counter substrate.

FIGS. 5 and 6 show only a part of a liquid crystal display device with a built-in peripheral driving circuit. In addition, a liquid crystal display device with a built-in peripheral driving circuit is composed of a polarizing plate, a phase film, an external circuit, and the like. Is configured.

Although FIG. 1 shows the connection of three transistors, thousands or tens of thousands of transistors are actually wired to form a peripheral driving circuit.

Although the above configuration is not directly disclosed, a liquid crystal display device with a built-in peripheral driving circuit is described in, for example, magazine "Flat Panel Display 1999" (published by Nikkei BP, December 14, 1998), pp. 132-139 . <br/>.

Further, as for the reflection type liquid crystal display device with a built-in peripheral circuit, for example, “SID 98 DIGEST”
225 to 228.

[0008]

In a conventional liquid crystal display device with a built-in peripheral driving circuit, a first wiring (a gate electrode and a wiring formed at the same time) and a second wiring (a source / drain electrode). At the same time, the circuit connection of the thin film transistor of the peripheral drive circuit portion is performed only by the wiring formed at the same time. For this reason, the circuit wiring layout is often limited only by the two-layer wiring, which hinders the enhancement of the function and the performance of the circuit.

SUMMARY OF THE INVENTION The present invention provides a liquid crystal with a built-in peripheral driving circuit which can increase the degree of freedom of circuit wiring layout and realize high functionality and high performance of a circuit without using a method which increases the cost. It aims at providing a display device.

[0010]

According to a first aspect of the present invention, there is provided a liquid crystal display device with a built-in peripheral driving circuit, wherein a first wiring formed by processing a first metal thin film forming a gate electrode of a thin film transistor, and a source and a source of the thin film transistor are formed. A second wiring formed by processing a second metal thin film contacting the drain region;
A third wiring formed by processing a third metal thin film used as a reflective pixel electrode; and a first wiring, a second wiring, and a third wiring.
Are part of the peripheral drive circuit.

According to the liquid crystal display device with a built-in peripheral driving circuit according to the first aspect, the first to third wirings enable a three-dimensional wiring on the transistor, so that circuit connection and circuit layout can be reduced. This facilitates the enhancement of the functions and performance of the circuit, and also facilitates the increase in wiring density and the reduction of the circuit area. In addition, since the third wiring and the reflective pixel electrode are formed at the same time, there is no increase in the number of steps and no reduction in yield. When the third wiring is made of another material without depending on the present invention, a film forming process including an interlayer insulating film, a masking process, and an etching process are each required twice in order to increase the number of wirings for one layer. Become.

According to a second aspect of the present invention, there is provided a liquid crystal display device with a built-in peripheral drive circuit according to the first aspect, wherein an insulating film is formed on the thin film transistor, and a third metal thin film is formed thereon and the third wiring. And

According to the liquid crystal display device with a built-in peripheral driving circuit according to the second aspect, the same effect as that of the first aspect can be obtained.

According to a third aspect of the present invention, in the liquid crystal display device with a built-in peripheral driving circuit, the thin film transistor is a polysilicon thin film transistor.

According to the liquid crystal display device with a built-in peripheral driving circuit according to the third aspect, the same effects as those of the second aspect can be obtained.

[0016]

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to FIG.

FIGS. 1 and 2 are partial schematic cross-sectional views of a main part of a liquid crystal display device with a built-in peripheral driving circuit. FIG.
Reference numeral denotes a peripheral drive circuit portion, which is composed of P-type and N-type (CMOS configuration) thin film transistors. FIG. 2 shows a screen unit. 1 and 2 (the same components as those in FIGS. 5 and 6 are denoted by the same reference numerals). Reference numeral 1 denotes a glass substrate, for example, a high heat-resistant glass substrate having a strain point of 650 ° C.
Is an insulating film, for example, SiO ₂ , 3 is a polysilicon layer, for example, a polysilicon layer crystallized by laser annealing, 4 is a gate insulating film, for example, SiO ₂ , and 5 is a gate electrode, for example, an electrode using Cr. Yes, the first metal thin film is processed to form a first wiring together with a gate electrode. Reference numeral 6 denotes a source region, 7 denotes a drain region, 8 denotes an interlayer insulating film such as SiO ₂ , 9 and 10 denote source / drain electrodes contacting the source region and the drain region. The second wiring is formed together with the source / drain electrodes by processing the second metal thin film. For example, one polysilicon thin film transistor is constituted by 3 to 10. Reference numeral 11 denotes an acrylic flattening film, which is an insulating film, for example, having a thickness of 3 μm. Reference numeral 12 denotes a reflective pixel electrode, which is connected to the drain electrode 10.
Reference numeral 13 denotes the same third metal thin film as that of the reflective pixel electrode 12, which is simultaneously processed to form a third wiring. 14 is a liquid crystal, 15 is an alignment film, 16 is a transparent electrode, 1
7 is a counter substrate. The material of the third wiring is, for example, Al,
It is made of AlTa, Ag, or the like, and is connected to the source electrode 9 or the drain electrode 10.

FIGS. 1 and 2 show only a part of a liquid crystal display device with a built-in peripheral driving circuit. In addition, a liquid crystal display device with a built-in peripheral driving circuit is composed of a polarizing plate, a phase film, an external circuit and the like. The device is configured.

Although FIGS. 1 and 2 show the connection of three transistors, thousands or tens of thousands of transistors are actually wired to form a peripheral driving circuit.

According to the first embodiment, the degree of freedom of the circuit wiring layout is greatly increased by using three layers of wiring.

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to FIG.

FIG. 3 and FIG. 4 are partial schematic cross-sectional views of main parts of a liquid crystal display device with a built-in peripheral driving circuit.
FIG. 3 shows a peripheral drive circuit section, which is a P-type and an N-type (CMOS).
Configuration) It is composed of a thin film transistor. FIG. 4 shows a screen unit. In FIGS. 3 and 4 (the same components as those in FIGS. 5 and 6 are denoted by the same reference numerals), 1 is a glass substrate, for example, a high heat-resistant glass substrate having a strain point of 650 ° C.
103 is a polysilicon layer, for example, a polysilicon layer crystallized by laser annealing, 104A is a gate insulating film, for example, SiNx, 104B is a gate insulating film, for example, SiO ₂ , and 105 is a gate electrode, for example, an electrode using Cr. Yes, the first metal thin film is processed to form a first wiring together with a gate electrode. Reference numeral 118 denotes an insulating film such as SiO _{2, reference} numeral 6 denotes a source region, reference numeral 7 denotes a drain region, reference numeral 8 denotes an interlayer insulating film such as SiO ₂ , and reference numerals 9 and 10 denote source and source regions which contact the source region and the drain region. A second metal thin film is processed using, for example, Al to form a second wiring together with the source / drain electrodes. 6 to 10, 103,
104A, 104B, 105, and 118, for example, 1
One polysilicon thin film transistor is formed.
Reference numeral 11 denotes an acrylic planarizing film which is an insulating film, for example, having a thickness of 3
A film 12 μm, 12 is a reflective pixel electrode, and 13 is the same third metal thin film as the reflective pixel electrode 12, and is processed at the same time to form a third wiring. 14 is a liquid crystal, 1
5 is an alignment film, 16 is a transparent electrode, and 17 is a counter substrate.

The third wiring 13 is connected in the same manner as in the first embodiment.

FIGS. 3 and 4 show only a part of the liquid crystal display device with a built-in peripheral driving circuit. In addition, a liquid crystal display device with a built-in peripheral driving circuit using a polarizing plate, a phase film, an external circuit, or the like. The device is configured.

FIGS. 3 and 4 show the connection of three transistors, but in practice thousands or tens of thousands of transistors are wired to form a peripheral drive circuit.

According to the second embodiment, the use of three-layer wiring greatly increases the degree of freedom in circuit wiring layout.

[0027]

According to the liquid crystal display device with a built-in peripheral driving circuit according to the first aspect of the present invention, the first to third wirings enable a three-dimensional wiring on the transistor. The layout becomes easy, the function and the performance of the circuit become easy, and the wiring density and the circuit area also become easy. In addition, since the third wiring and the reflective pixel electrode are formed at the same time, there is no increase in the number of steps and no reduction in yield. In the case where the third wiring is formed of another material without depending on the present invention, a film forming process including an interlayer insulating film, a masking process, and an etching process are each required twice in order to increase the number of wirings for one layer. Become.

According to the liquid crystal display device with a built-in peripheral driving circuit according to the second aspect, the same effects as those of the first aspect can be obtained.

According to the liquid crystal display device with a built-in peripheral driving circuit according to the third aspect, the same effects as those of the second aspect can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a peripheral drive circuit unit for describing a liquid crystal display device with a built-in peripheral drive circuit according to a first embodiment of the present invention;

FIG. 2 is an explanatory diagram of the screen unit.

FIG. 3 is an explanatory diagram of a peripheral drive circuit unit for describing a liquid crystal display device with a built-in peripheral drive circuit according to a second embodiment of the present invention;

FIG. 4 is an explanatory view of the screen section.

FIG. 5 is an explanatory diagram of a peripheral drive circuit portion for describing a conventional liquid crystal display device with a built-in peripheral drive circuit.

FIG. 6 is an explanatory diagram of the screen section.

[Explanation of symbols]

 Reference Signs List 1 glass substrate 2 insulating film 3 polysilicon layer 4 gate insulating film 5 gate electrode (first wiring) 6 source region 7 drain region 8 interlayer insulating film 9 source electrode (second wiring) 10 drain electrode (second wiring) 11) Flattening film 12 Reflecting pixel electrode 13 Third wiring 14 Liquid crystal 15 Alignment film 16 Transparent electrode 17 Counter substrate 103 Polysilicon layer 104A Gate insulating film 104B Gate insulating film 105 Gate electrode 118 Insulating film

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 29/786 H01L 29/78 612B 612C 619B F-term (Reference) 2H092 GA59 JA25 JA26 JA34 JA37 JA41 JB07 JB22 JB31 JB57 JB58 KA04 MA13 MA17 MA30 NA27 NA29 PA09 PA10 PA11 PA12 5C094 AA15 AA21 BA03 BA43 CA19 CA24 DA09 DA14 DA15 EA04 EA05 EA06 EA07 EB02 ED11 5F110 AA04 AA16 AA30 BB02 BB04 CC02 CC08 DD02 NN03 FF03 NN03 FF03 NN03 FF03 NN03 FF04 5G435 AA16 AA18 BB12 EE33 EE37 GG21 HH12 HH14

Claims (3)

[Claims] A first wiring formed by processing a first metal thin film forming a gate electrode of the thin film transistor; a second wiring formed by processing a second metal thin film contacting a source / drain region of the thin film transistor; A third wiring formed by processing a third metal thin film used as a reflective pixel electrode, wherein the first wiring, the second wiring, and the periphery having the third wiring as a part of a peripheral driving circuit; Liquid crystal display device with built-in drive circuit. 2. An insulating film is formed on the thin film transistor,
2. The liquid crystal display device with a built-in peripheral driving circuit according to claim 1, further comprising a pixel electrode formed by processing a third metal thin film and a third wiring thereon. 3. The liquid crystal display device with a built-in peripheral driving circuit according to claim 2, wherein the thin film transistor is a polysilicon thin film transistor.