CN1317106A - Active matrix liquid crystal display and method for producing the same - Google Patents

Abstract

Simultaneously carry out pattern formation for opening and removing the second insulating film (6) to lay the scanning signal lines (2) and video signal lines (5), and opening and removing the first insulating film (3) to realize the scanning signal lines ( 2) Patterning of layer transitions between layers and video signal lines (5) layers. Thus, the number of cycles of the photolithography process in the TFT array process is reduced to five. In addition, the scanning signal line (2) layer and the video signal line (5) layer are electrically connected through the pixel electrode (7) layer.

Description

Active matrix type liquid crystal display device and manufacturing method thereof

The present invention relates to an active matrix type liquid crystal display device that displays images by driving liquid crystals with switching elements and a manufacturing method thereof.

In recent years, display devices using liquid crystals to display images have been widely used because they have advantages of thinness, light weight, and low power consumption, which are features that existing display technologies using CRTs and the like do not have. Among them, in particular, an active matrix type liquid crystal display device (hereinafter referred to as "AMTLCD device") is provided with a switching element including a thin film transistor (hereinafter referred to as "TFT") for each pixel arranged in a matrix, and through the switching element Drives the liquid crystal to display images. Because the AMTLCD device displays clear images and has less interference, it has been rapidly utilized in recent years, such as being used for display in notebook personal computers and car navigation devices.

Next, an example of a conventional AMTLCD device will be described with reference to the accompanying drawings.

FIG. 2 shows a portion of an array of existing AMTLCD devices with TFTs.

As shown in Figure 2, existing AMTLCD devices include:

(a) A glass substrate as an insulating transparent substrate that is part of a TFT array

1;

(b) double as the grid of TFTs arranged in a matrix on the glass substrate 1,

And provide the scanning signal line 2 of the scanning signal to the gate;

(c) Covering the first insulation layer formed on the scanning signal line 2 as the first insulating layer

An insulating film, which is used as a gate insulating film 3 for insulating the gate of the TFT;

(d) Formed on the TFT first insulating film (i.e. gate insulating film) 3 for

Amorphous silicon film 4 forming the channel region of the TFT;

(e) doubles as the source connected to the amorphous silicon film 4 of the TFT, and is used to provide

The video signal line 5 of the image signal;

(f) The second insulating film 6 constituting the second insulating layer is used as a protective film for the TFT.

The passivation insulating film of the protective film;

(g) a plurality of pixel electrodes 7 arranged in a matrix;

(h) The contact formed after the hole is opened to remove the passivation insulating film, that is, the second insulating film 6

Contact hole pattern 8;

(i) The contact hole pattern 10 after opening the hole to remove the layer of the first insulating film 3;

as well as

(j) Drain 11.

In the above structure:

(a) A plurality of pixel electrodes 7 are arranged in a matrix;

(b) A plurality of TFTs are also arranged in a matrix corresponding to the pixel electrodes 7;

(c) The video signal line 5 also serves as the source connected to the amorphous silicon film 4 of the TFT,

providing an image signal to the pixel electrode 7 through the drain 11; and

(d) The second insulating film 6 is a passivation insulating film serving as a protective film of the TFT, and

Constitutes the second insulating layer.

Regarding the AMTLCD device constructed as above, how it operates will be described below.

Existing AMTLCD devices work as follows:

(a) First apply the voltage to the scanning signal line 2;

(b) forming a channel of a TFT in the amorphous silicon film 4 by means of the voltage;

(c) When the channel is formed, the image signal passes through the TFT signal from the video signal line 5

The channel is passed to the drain 11;

(d) The image signal is further transmitted to the pixel electrode 7;

(e) pass on the pixel electrode 7, and on the color filter (not shown in the figure)

The electricity generated between the opposite electrodes (not shown in the figure) formed in parallel

field, freely changing the liquid injected and retained between the pixel electrode 7 and the counter electrode

Crystal orientation; thus

(f) The light transmittance can be adjusted by freely changing the liquid crystal orientation.

The required image is generated through the above actions and displayed on the screen of the AMTLCD device.

In the aforementioned AMTLCD device, the processing technology of forming an array of TFTs on the glass substrate 1 is a tedious and complicated process that repeats the following steps:

(a) film formation, followed by

(b) forming a resin pattern by a photolithography process,

(c) Etching to remove unnecessary film parts, followed by

(d) Remove the resin pattern.

By reducing the number of cycles of the photolithography process and shortening the development cycle of the entire manufacturing process, product costs and defect rates can be reduced.

In the above AMTLCD device manufacturing process, the photolithography process is repeated six times in total, which are:

(a) Pattern formation for forming the scanning signal line 2;

(b) Pattern formation for forming the video signal line 5 and the drain electrode 11;

(c) Patterning for forming the amorphous silicon film 4;

(d) patterning for forming the pixel electrode 7;

(e) In order to realize the installation and wiring of the write scanning signal line 2 and the video signal line 5

And the patterning of the passivation insulating film 6 is removed;

(f) In order to perform layering between the scanning signal line 2 layer and the video signal line 5 layer

The patterning of the first insulating film (gate insulating film) is removed by switching.

However, as described above, in the above method of manufacturing the related art AMTLCD device, six cycles of repeating the photolithography process are necessary. Thus, there is a problem that the photolithography process is a major cause of increasing the cost of the entire manufacturing process because it makes the manufacturing cycle of the entire process lengthy.

The purpose of the present invention is to solve the aforementioned problems in the prior art, and provide an AMTLCD device and a manufacturing method thereof, which can reduce the number of cycles of repeating the photolithography process in the TFT array process, and shorten the entire process including the above-mentioned process. The manufacturing cycle, thereby reducing the cost of the entire manufacturing process of the TFT array.

In order to achieve the above object, the AMTLCD device of the present invention and its manufacturing method are to complete the following steps simultaneously (i.e. once):

(a) Developed for the implementation of the installation and wiring of the write scan signal line and the video signal line

hole removal patterning of the second insulating layer; and

(b) In order to perform layer transformation between the scanning signal line layer and the video signal line layer

While openings are removed from the patterning of the first insulating layer.

Therefore, the number of cycles for repeating the photolithography process in the TFT array process can be reduced to five times. In addition, it is characterized in that the scanning signal line layer and the video signal line layer are electrically connected by using the pixel electrode layer.

The AMTLCD device of the present invention displays images on the screen in the following manner:

(a) sandwiching liquid crystals between insulating transparent substrates facing each other; and

(b) Drive the liquid through the scan signal and the image signal corresponding to the display image

crystal to display the image on the above screen.

In the AMTLCD device, a plurality of pixels for displaying images are arranged in a matrix on an insulating transparent substrate, and the array part includes:

(a) at least in some way a plurality of matrix-shaped

The pixel electrodes arranged in a pattern;

(b) Thin-film crystals arranged in such a way that they respectively correspond to the pixel electrodes

Multiple switching elements composed of tubes;

(c) for providing scanning signals to the respective gates of the plurality of switching elements

Multiple scanning signal lines;

(d) a plurality of video signal lines for respective sources via said plurality of switching elements

The electrode and the drain provide image signals to the pixel electrodes;

(e) covered on the plurality of scanning signal lines and used as the plurality of switch elements

The first insulating layer of the insulating film of the gate of the device; and

(f) Overlaid on said plurality of video signal lines, used as a plurality of switching elements

The second insulating layer of the protective film.

According to the above constitution, the active matrix type liquid crystal display device of the present invention is:

(a) Part of the pixel electrode passes through the contact hole formed in the second insulating layer

The pattern is electrically connected to the video signal line,

(b) and also through contact hole patterns formed in the first and second insulating layers and

Electrical conduction of the scanning signal line; and

(c) It displays images by driving liquid crystals with scanning signals and image signals,

The signal turns on and off the switching element through the pixel electrode.

Therefore, the present invention can reduce the cycle number of the photolithography process in the repeated TFT array process, and shorten the manufacturing cycle of the entire process including the above process, thereby reducing the cost of the entire manufacturing process of the TFT array.

Fig. 1 shows the AMTLCD device and manufacturing method thereof of typical embodiments of the present invention;

FIG. 2 shows a conventional AMTLCD device and its manufacturing method.

Hereinafter, an AMTLCD device and a manufacturing method thereof according to exemplary embodiments of the present invention will be specifically described with reference to the accompanying drawings.

FIG. 1 shows a part of the AMTLCD device of this embodiment, and the same reference numerals are used for the same elements as in FIG. 2 showing the prior art device.

As shown in Figure 1, the AMTLCD device of the present embodiment comprises:

(a) Glass substrate 1 as an insulating transparent substrate;

(b) also serves as the grid of TFTs arranged in a matrix on the glass substrate 1

pole and provide scanning signal line 2 for scanning signal to the gate of the TFT;

(c) Covering the first insulating layer forming the first insulating layer on the scanning signal line 2

film, as a gate insulating film 3 opposite to the TFT gate;

(d) Formed on the TFT first insulating film (i.e. gate insulating film) 3, with

An amorphous silicon film 4 used to form the channel region of the TFT;

(e) A video signal line 5 for providing image signals, which also serves as

The source connected to the amorphous silicon film 4 of the TFT;

(f) The second insulating film 6 constituting the second insulating layer, which is used as a TFT protection

The passivation insulating film of the protective film;

(g) a plurality of pixel electrodes 7 arranged in a matrix;

(h) Formed after removing the passivation insulating film as the second insulating film 6 after opening

Formed contact hole pattern 8;

(i) The contact hole pattern 9 between the pixel electrode 7 and the scanning signal line 2;

as well as

(j) The drain 11 connected to the amorphous silicon film 4 of the TFT.

In the above structure:

(a) A plurality of pixel electrodes 7 are arranged in a matrix;

(b) Corresponding to the pixel electrode 7, multiple TFTs are also arranged in a matrix;

(c) The video signal line 5 also doubles as a source connected to the TFT amorphous silicon film 4

pole, providing an image signal to the pixel electrode 7 through the drain 11;

(d) The second insulating film 6 is made of, for example, SiN _x , SiO ₂ , acrylic resin,

Films of polyimide, polyamide or polycarbonate or laminates thereof;

(e) The pixel electrode 7 and the drain electrode 11 are electrically connected through the contact hole pattern 8 .

FIG. 1 showing the present embodiment differs from FIG. 2 showing the prior art example in the following points.

The difference lies in the electrical connection between the layer of the scanning signal line 2 and the layer of the video signal line 5 . As shown in FIG. 2, in the past, the contact hole pattern 10 was formed after the first insulating film 3 layer was removed. Electrical connection is then directly made between the scanning signal line 2 and the video signal line 5 .

In the present embodiment, however, as shown in the wiring conversion portion of FIG. 1, the openings on the upper surfaces of the scanning signal lines 2 are formed by removing the first insulating film 3 and the second insulating film 6 simultaneously after depositing the second insulating film 6. hole. The contact hole pattern 9 is formed between the pixel electrode 7 and the scanning signal line 2 in such a way that a part of the pixel electrode 7 and the scanning signal line 2 are connected to each other on the surface. By forming in this way, the scanning signal line 2 and the video signal line 5 are electrically connected indirectly through the pixel electrode 7 .

In this embodiment, the following steps are completed simultaneously (once):

(a) Remove the hole for assembling the scanning signal line 2 and the video signal line 5

A passivation insulating film as the second insulating film 6 is patterned; and

(b) In order to carry out between the 2nd layer of the scanning signal line and the 5th layer of the video signal line

The layer is transformed, and the opening removes the gate insulating film as the first insulating film 3, forming a pattern

case.

Therefore, the number of cycles of the photolithography process described above can be reduced to five times. This can shorten the manufacturing cycle of the overall manufacturing process, thereby reducing the cost of the overall process.

The manufacturing method of the array substrate of the AMTLCD device comprised as above comprises the following steps:

(a) First, deposit a thin film by sputtering film forming method, and form a film on the glass substrate 1

into a scanning signal line 2; and

(b) Patterning the scanning signal line 2 through a photolithography process and an etching process.

By repeatedly depositing thin films and patterning them with photolithography and etching processes, these processes of the present invention are accomplished:

(a) forming an amorphous silicon film 4;

(b) forming a video signal line 5;

(c) forming the drain 11; and

(d) Forming the pixel electrode 7.

As described above, by simultaneously removing the first insulating film 3 and the second insulating film 6 after depositing the second insulating film 6, openings on the surface of the scanning signal lines 2 are formed in the wiring conversion portion. The scanning signal line 2 and the video signal line 5 are formed such that they are electrically connected indirectly through the pixel electrode 7 . In order to implement the wiring between the scanning signal line 2 and the video signal line 5 in the AMTLCD device of the above-mentioned constitution, complete the following steps simultaneously (once):

(a) patterning for removal of the passivation insulating film; and

(b) In order to perform layering between the scanning signal line 2 layer and the video signal line 5 layer

Transform and open holes to remove the gate insulating film and form a pattern.

Therefore, the number of cycles of the photolithography process can be reduced to five times.

As a result, many processes such as thin film deposition, photolithography process, etching process, cleaning process, etc. that are required elsewhere can be substantially reduced in the array process. Moreover, the manufacturing cycle of the array process can be greatly shortened, thereby achieving a reduction in process cost.

According to the present invention as described above, the steps of patterning to remove the second insulating layer for implementing wiring between the scanning signal line and the video signal line, and performing wiring between the scanning signal line layer and the video signal line are simultaneously (once) performed. Patterning in which the first insulating layer is removed by layer switching between layers. Thus, the number of cycles of the photolithography process in the TFT array process can be reduced to five times, and at the same time, the pixel electrode layer can be used to form an electrical connection between the scanning signal line layer and the video signal line layer.

In this way, the number of cycles of the photolithography process in the TFT array process can be reduced, and the manufacturing cycle of the entire process including the above process can be shortened, thereby reducing the cost of the entire manufacturing process of the TFT array.

Claims (5)

1. An active matrix type liquid crystal display device, comprising: (a) a plurality of scanning signal lines for supplying scanning signals to respective gates of the plurality of switching elements; (b) a plurality of video signal lines for supplying image signals to the pixel electrodes through respective sources and drains of the plurality of switching elements; (c) a first insulating layer covering the plurality of scanning signal lines for insulating gates of the plurality of switching elements; and (d) a second insulating layer covering the plurality of video signal lines for insulating the plurality of switching elements; And the liquid crystal display device is constituted in the following manner: (e) A part of the pixel electrode is electrically connected to the video signal line through the contact hole pattern formed on the second insulating layer, and another part is electrically connected to the video signal line through the contact hole pattern formed on the first and second insulating layers. Another contact hole pattern is electrically connected to the scanning signal line. 2. The active matrix type liquid crystal display device according to claim 1, wherein said first insulating layer is a multilayer structure including a semiconductor layer. 3. The active matrix type liquid crystal display device as claimed in claims 1 and 2, wherein said second insulating layer is a transparent resin of acrylic resin, polyimide, polyamide or polycarbonate, or a polyamide containing these resins layer structure. 4. A method of manufacturing an active matrix type liquid crystal display device, wherein the method includes a process of forming a constituent element including a plurality of switching elements in an array portion having a plurality of Image display pixels arranged in a matrix, the process includes: (a) first step: forming at least a plurality of scanning signal lines for supplying scanning signals to respective gates of the plurality of switching elements and serving as gate anti-truth lines of the respective gates by selectively etching; (b) second step: forming each channel portion of the plurality of switching elements; (c) The third step: by selectively etching, forming a plurality of switching elements for supplying the image signal to the pixel electrode through each source and drain of the plurality of switching elements, and serving as the plurality of sources. Multiple video signal lines of the source anti-true line; (d) a fourth step of selectively etching an insulating film covering the gates of the plurality of scanning signal lines for insulating the gates of the plurality of switching elements, and covering the gates of the plurality of video signal lines on each insulating layer of the protective film for protecting the plurality of switching elements, and simultaneously form openings on the surfaces of the plurality of scanning signal lines and the plurality of video signal lines; (e) fifth step: forming the plurality of pixel electrodes by selectively etching; and (f) The sixth step: forming an assembly terminal on any layer of the scanning signal line layer and the video signal line layer, covering the pixel electrode layer on its upper part, and covering the upper part with an anisotropic conductive film Press install. 5. 4. The method of manufacturing an active matrix type liquid crystal display device as claimed in claim 4, wherein said first step to said sixth step are performed in said order.

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