JPH03289629A - Image display device and its manufacture - Google Patents

Abstract

PURPOSE:To prevent liquid crystal on a picture element electrode from being affected by the AL signal line of an adjacent picture element by providing an insulating film in an area including a vertical signal line and extending a picture element electrode onto the insulating film and onto the vertical signal line through the insulating film. CONSTITUTION:A 1st insulating film 15 made of a BPSG (boron-phosphours silicate glass) film is grown, a contact hole is bored, and an AL signalline 16 is formed; and then a 2nd insulating film 1 made of an NSG (Nondoped- Silicate Glass) film is grown, a contact hole is bored, and a picture element electrode 17 is formed of an ITO film. At this time, an end part of the picture element electrode 17 is patterned covering the part above the AL signal line 16 of the adjacent picture element and a protection film 18 consisting of an SOG (Spin Glass) film is formed finally. consequently, the liquid crystal on the picture element electrode 17 is not affected by the AL signal line 16 of the adjacent picture element.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image display device formed using thin film transistors on an insulating substrate and a method for manufacturing the same.

2. Description of the Related Art Thin film transistors are widely used as active matrix elements in conventional image display devices.

A conventional image display device will be described below with reference to FIG. As shown in the figure, there is a switching thin film transistor (hereinafter referred to as TPT) made of polysilicon 12 on a quartz substrate 11, and a gate electrode 14 is provided with a gate insulating film 13 interposed therebetween. 15 is a first insulating film made of a BPSG (boron-phosphosilicate glass) film;
An AL (vertical) signal line 16 is formed in the source region, a pixel electrode 17 made of an ITO film is formed in the drain region, and a protective film 18 made of an SOG (5 pin on glass) film is formed on the entire surface. Note that the pixel electrode 17 made of an ITO film has a structure such that it does not come into contact with the AL signal line 16 of an adjacent pixel.

Problems to be Solved by the Invention In such a conventional image display device, the pixel electrode 17 made of an ITO film is prevented from coming into contact with the adjacent AL signal line 16. The liquid crystal located above the end of the pixel electrode 17 made of a film and above between the pixel electrode 17 and the AL signal line 16 is affected by the seepage of the electric field from the AL signal line 16. As a result, pixels at the contact area may become defective or
There were issues with the light leaking from the Tsukurite and the amount of transmitted light decreasing.

The present invention solves the above-mentioned problems, and has a certain pixel electrode 17.
It is an object of the present invention to provide an image display device in which an upper liquid crystal is not affected by the AL signal line of an adjacent pixel, and a method for manufacturing the same.

Means for Solving the Problems In order to achieve the above objects, the present invention provides a thin film transistor as an active matrix element formed on an insulating substrate, a vertical signal line connected to the source, and a pixel connected to the drain. In an image display device configured with an electrode, an insulating film is provided on at least a region including the above-mentioned vertical signal line, and the above-mentioned pixel electrode is provided on the insulating film and on the above-mentioned vertical signal line via the insulating film. It has a stretched structure.

According to the above-described structure, the pixel electrode is formed to extend over the AL signal line through the insulating film, so that the pixel electrode is closer to the liquid crystal than the AL signal line, and the liquid crystal on the pixel electrode is The effect of the electric field from the AL signal line below the pixel electrode is eliminated, and there is no contact between the pixel electrode and the AL signal line.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 and 2, and parts that are the same as those of the conventional example in FIG. Let's explain the parts. In other words, the feature of the present invention in FIG.
-S 1licate Glass) film, etc.
An insulating film 1 is provided, and a pixel electrode 17 made of an ITO film is formed thereon.

Next, the manufacturing method will be explained. First, a polysilicon thin film 12 of 200 OA is formed on a quartz substrate 11 by the LPCVD method as shown in FIG. An insulating film 13 (1300 people) and a gate electrode 14 made of polysilicon are formed. Then, impurities such as phosphorus ions or arsenic ions are implanted in the self-alignment. Next, as shown in the same figure (C1), a first insulating film made of BPSG film is formed. The insulating film 15 (8,000 layers) is lengthened and a contact hole is made to form an AL signal line 16. Next, as shown in the same figure (dl), a second insulating film made of an NSC film, which is a feature of the present invention, is formed. Film 1 (3000 layers) is lengthened, a contact hole is made, and a pixel electrode 17 made of an ITO film is formed. A protective film 18 made of an SOG film is applied to form a pixel as shown in FIG. 1.

Next, the characteristics of the operation of the image display device of the present invention will be explained. Information from the AL signal line 16 is the switching TP
It passes through T and is sent to the pixel electrode 17. This applies an electric field to the liquid crystal on the pixel electrode 17, making it possible to control the light transmittance.

In this way, the second insulating film 1 made of the NSC film is formed between the pixel electrode 17 and the AL signal line 16 of the adjacent pixel, and the pixel electrode 17 is formed so as to cover the AL signal line 16. As a result, the AL signal line 16 and the pixel electrode 17 do not come into contact with each other, and the liquid crystal near the end of the pixel electrode 17 is not affected by the electric field from the AL signal line 16 and is no longer exposed to light. Furthermore, since there is no need to separate the pixel electrode 17 and the AL signal line 16 as in the conventional case, it is possible to cope with miniaturization and a reduction in the area of the pixel.

Note that in this embodiment, the TPT has a dual gate, but other configurations may be used. Furthermore, TPT may be a P-channel transistor. Furthermore, the pixel electrode 17 may be made of a film other than ITO, and the second insulating film 1 formed between it and the AL signal line 16 may also be made of a material other than NSCSC. Further, the quartz substrate 11 may also be an insulating substrate such as glass.

Effects of the Invention As is clear from the above embodiments, the present invention provides an insulating film over a region including at least a vertical signal line, and a pixel electrode extends over the insulating film and onto the vertical signal line through the insulating film. Since the structure is formed using a pixel electrode, there is no adverse effect such as leakage light due to the electric field from the liquid crystal above the pixel electrode or the AL signal line below the pixel electrode, and there is no possibility of pixel failure due to contact between the pixel electrode and the AL signal line. It is possible to provide an image display device capable of displaying a stable image without image distortion, and a method for manufacturing the same.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of an image display device according to an embodiment of the present invention, FIG. 2 (far to fd) is a sectional view of the manufacturing process of the embodiment of FIG. FIG. 1... Insulating film, 11... Quartz substrate (insulating substrate), 12... Borin silicon (part of thin film transistor), 13... Gate insulating film ( part of thin film transistor), 14... gate electrode (
(part of thin film transistor), 16... AL (vertical) signal line, 17... pixel electrode.

Claims (2)

[Claims] (1) In an image display device configured with a thin film transistor as an active matrix element formed on an insulating substrate, a vertical signal line connected to a source, and a pixel electrode connected to a drain, at least the vertical signal An image display device having a structure in which an insulating film is provided on a region including a line, and the pixel electrode is formed on the insulating film and extending over the vertical signal line through the insulating film. (2) A process of forming a polysilicon thin film that will become a thin film transistor region on an insulating substrate, a process of forming a gate electrode on a predetermined portion of the polysilicon thin film via a gate insulating film, and using the gate electrode as a mask to inject impurities. A process of implanting a source and a drain to form a source and a drain, and a step of implanting a first
a step of forming an insulating film on the first insulating film, a step of patterning a vertical signal line connected to the source on the first insulating film, and a step of forming a second insulating film on the entire surface including the top of the vertical signal line. a step of forming a contact hole by combining the first insulating film and the second insulating film; A method for manufacturing an image display device, comprising the steps of patterning a pixel electrode extending onto a signal line, and forming a protective film over the entire surface.