JPS61292615A - Display device - Google Patents

Abstract

PURPOSE:To eliminate the need for separate source electrodes and to eliminate the loss of the area of segment electrodes at said points by providing a regment electrode formed with a semi-metallic layer consisting of a high melting metal diffused therein with the semiconductor component of a semiconductor film at the extended point of the semiconductor film of a switching transistor (TR). CONSTITUTION:Gate lines 18 having gate electrodes 19 consisting of two-layered films composed of gold and chrominum are formed on a glass substrate 10. An insulating film 12 consisting of silicon nitride is formed thereon and further an amorphous silicon film is formed thereon to simultaneously pattern and form amorphous silicon film lines 13, operating regions 14 of the switching TRs and electrode regions S1. The chromium film is deposited by evaporation only on the electrode region S1 continuous immediately with the operating region 14 and is subjected to a heating treatment. The semi-metallic layer S2 consisting of chromium and silicon is formed to about 50Angstrom on the surface. The remaining chromium is thereafter removed by etching, then the light transmittable segment electrode 11 consisting of the amorphous silicon having the semi-metallic layer S2 on the surface part is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION 0) Industrial Field of Application The present invention relates to a method of manufacturing an active matrix display device having a matrix of display segments coupled to switching transistors.

(b) Conventional technology As a display device having matrix-like display segments, there is a liquid crystal display as disclosed in the article "Flat panel display aimed at displaying documents and images" in the January 2, 1984 issue of Nikkei Electronics. Those using a display device,
There are various types of display devices using electroluminescence display devices, but liquid crystal display devices are currently highly regarded for their potential in the future as they can be manufactured with low power consumption and large capacity.

A plan view of the main parts of such a conventional liquid crystal display device is shown in FIG.
), and a cross-sectional view taken along line X-X is shown in ) of the same figure. In these figures, (lQF!, first glass substrate.

αD... is a first glass substrate (1) arranged in rows and columns (approximately 25 CIX1
500) is a segment electrode made of transparent ITO. α3... is the segment electrode nuttu...
・It is an amorphous silicon film line arranged vertically in parallel on the insulating film Ω in the gap, and each segment electrode (
A semiconductor operating area (141fi4...) is provided protruding from the lower left space of Ill(lυ...).α
9... is each amorphous silicon film line fi3...
- It is a drain line consisting of an aluminum gland arranged above, and a drain electrode α0161 superimposed on the left side of each of the semiconductor operating regions (141 (141) is protruded. (171 (17) . . . Each semiconductor operating area Q4
1 (141...) is a source electrode consisting of an aluminum gland partially superimposed on the right side of the insulating film α.
2 and connected to the lower left end of each corresponding segment electrode α1lfiυ.... a8... are the segment electrodes (113 (111...) arranged horizontally in parallel at the gap position, and the gold formed between the glass substrate (11) and the insulating film α1 of $1 above. The gate line is made of a two-layer film of chromium, and the line α... has a semiconductor operating region [141 below the gate electrode] located in the gap between each source electrode surface... and the drain electrode rie... a9...
・Protruded integrally. That is, the drain electrode αe shown in Fig. 1, and the source electrode (17) shown by 8.
The thin film F' is formed by the gate electrode α9 indicated by G, and the semiconductor operating region a4 made of the amorphous silicon film bonded to these electrodes, S, and G.
Switching transistors of BT configuration are arranged in rows and columns, and each segment υσD... is connected to the drain line a through the corresponding switching transistor.
5... is connected. (100) is an alignment film that completely covers each of the segment electrodes α1+(11), the drain line a9, and the switching transistor.

On the other hand, ■ is the second glass substrate and its lower surface.

That is, a common electrode (2D) and an alignment film (200) are sequentially formed on the surface facing the first glass substrate a.

(to) is the distance between the two plates (1 [, ■, that is, the plane alignment film (100
), (200) It is a liquid crystal substance sealed in darkness.

A first glass substrate to which a display signal, that is, a liquid crystal excitation voltage is applied by turning on the switching transistor for each matrix segment. Become.

(c) Problems to be Solved by the Invention In the conventional display device as described above, the corner of the segment electrode αD is concave at the switching transistor location, and moreover, the segment electrode αD overlaps the source electrode (17) at this corner. Since the electrodes were connected together, there was a drawback that the area of the segment electrode (2) was small.

2) Means for Solving the Problems The display device of the present invention includes a semi-metal layer in which the semiconductor component of the semiconductor film is diffused in a high melting point layer on the extended portion of the semiconductor film of the switching transistor. It is equipped with formed segment electrodes.

(E) Function According to the display device of the present invention, since the semiconductor film of the switching transistor is directly connected to the semi-metalized segment electrodes, there is no need for a separate source electrode to connect them. Since the segment electrode is adjacent to the switching transistor, there is no area loss of the segment electrode at this location.

(f) Example 1 [J(a), (1)] shows a plan view and a sectional view of a display device of the present invention. In this figure, the same parts as those of the conventional device shown in FIG. 2 are given the same reference numerals. The display device in the same figure is M2
The difference from that in the figure is in the segment electrode συ, and due to this difference, a separate source electrode (17
) is no longer necessary.

That is, the segment electrode I is formed by diffusing the silicon of the segment electrode head region (Sl) into a high point metal such as chromium on the surface of the electrode region (81) further extending from the operating region a4 of the amorphous silicon film. A semi-metal layer (821) is formed, and this segment electrode 0 also serves as the source electrode portion of the switching transistor.

The sheet resistance of such silicon-chromium semi-metal layer (S2) is much lower than that of amorphous V silicon, and this semi-metal thin film layer has sufficient light transmittance, so it can be used as a transparent electrode instead of ITO. Furthermore, since ohmic contact is made to amorphous silicon, which is different from ITO, there is no need for a source electrode made of a different material such as aluminum.

Next, a method for manufacturing such a display device will be outlined. first.

Glass substrate α [Gate electrode 1 consisting of two layers of gold and chromium on top! Form a gate line α8t with J.

On top of that, an insulating film α2 made of silicon nitride was deposited using the plasma OVD method, and then a 100%
0A*32 is applied to the underlying amorphous silicon film. Then, this amorphous silicon film was formed into amorphous silicon film lines (13,
The operating region (14) and electrode region (31) of the switching transistor are patterned and formed at the same time. Next, a chromium film with a thickness of about 500A is formed only on the electrode region (Sl) that immediately extends from the operating region I made of amorphous silicon. is vapor-deposited and heat-treated at 200°C for 30 minutes.At this time, silicon in one display electrode area (Sl) is diffused into chromium, which is a high-temperature metal, and
) A semi-metal layer (Sl) of chromium-silicon is formed to a thickness of about 50R. After that, the semimetal @(a2
) Remaining chromium film 1 (NH4) 20e (NO 6
If removed by etching in an aqueous solution, the semi-metal layer (S
A light-transmitting segment electrode αυ made of amorphous silicon having a surface portion of the segment electrode αυ is obtained.

Finally, drain line r1 with drain electrode net made of aluminum? ) 1, and further an alignment film (10
0) A film is applied to 1 to complete the production of the first glass substrate side.

In the above explanation, chromium was exemplified as a high point metal, but this is not limited to chromium.
Any material may be used as long as the conductivity is improved by diffusion of the semiconductor component.

(g) Effects of the Invention According to the display device of the present invention, the semiconductor film of the switching transistor is directly connected to the semi-metalized segment electrodes, so there is no need for a separate source electrode to connect them. Since the upper segment electrode is adjacent to the switching transistor, there is no area loss of the segment electrode at this location. Therefore, if such a display device is used for a liquid crystal display, a sufficient amount of light can be obtained for each segment, resulting in a high-quality image display.

[Brief explanation of drawings]

Figures 1(a) and (1) are a plan view of the display device of the present invention and a sectional view taken along the line X-X, and Figures 2 (!L) and (1)) are a plan view of a conventional device and its cross-sectional view. It is a sectional view taken along the line X-X. α1) d... Segment electrode, r1 to insulating film, (1
m-・Amorphous silicon film line, (141・・
・Operating area, U51...Drain line, σG...
Drain electrode, (81)...electrode region, (82)...
・Semi-metal.

Claims (1)

[Claims] 1) A plurality of gate lines arranged in parallel intersect with a plurality of drain lines arranged in parallel on the gate lines via an interlayer insulating film, and a semiconductor film is arranged at each intersection in the matrix. In a display device comprising switching transistors consisting of FETs, and a display segment electrode coupled to the source side of each transistor, the display segment electrode is located on the surface of the extending portion of the semiconductor film of the switching transistor. A display device comprising a semi-metal layer in which a semiconductor component of a semiconductor film is diffused in a high-melting point metal.