JPS6150185A - Solid display unit and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Conventional Field of Application] The present invention relates to a semiconductor GL that is provided with a liquid crystal display panel to solidify the display section of a microcomputer, word processor, television, or the like.

``Prior Art'' For solid-state display panels, a system in which each picture element is controlled independently is effective for large-area displays. In a panel using such active elements, one pixel consists of one insulated field effect semiconductor device (IGF) and a liquid crystal element connected in series with it, and this is connected to X and Y wiring. It consists of a matrix structure.

``Problems to be solved by the invention'' However, in the display panel using this IGF, the number of photomasks required for the manufacturing process is 6 to 8, so it is expected that the manufacturing yield will be low. .

Furthermore, since the semiconductor for this IGF has a thin film structure, it is mainly manufactured using an amorphous semiconductor, but the physical properties of the interface between this amorphous semi-thin body and the gate insulator have not been fully elucidated.

This has caused fundamental problems such as variations in the threshold voltage of the IGF.

"An Unsuccessful Means to Solve the Problem" In order to solve this problem, the present invention does not use IGF as a system for controlling active elements, but instead uses sufficient technology to use diodes, especially solar cells, which is an effective field of amorphous semiconductors. It mainly uses a PIN type diode made of four non-single high school graduates to which accumulated hydrogen or halogen elements are added.

When such a diode uses forward charge, its build-in (rise) voltage is approximately constant at about 0.7V, and there is no manufacturing variation. Since the physical properties of the insulating film-semiconductor interface are not used, there is no instability in temperature treatment and B-T treatment (bias-temperature) treatment.

Further, in the present invention, at least two such diodes are connected in series in the same direction between the X wiring and the Y wiring, and the midpoint thereof is connected to one electrode of the liquid crystal display. Representative examples of such structures are shown in FIGS. 1 and 2.

Since the electrode of the liquid crystal is made from this midpoint, it is easy to control the AC bias to the liquid crystal by controlling the levels (11) and (12) of the other electrode of the liquid crystal, and it has the characteristics that gradation control is also possible. .

"Function" Furthermore, as shown in FIG. 3, the other electrode of the liquid crystal is divided into three parts, each of which is called red (referred to as R).

By passing the green (referred to as G) and blue (referred to as B) filters, a voltage can be applied independently to the level on the Z axis. Therefore, it has the feature of being able to perform gradations for R, G, and B.

Furthermore, the number of masks required in the process to produce this pattern may be four. For this reason, it is characterized by a higher manufacturing yield than the 6 to 8 TGF method.

The present invention will be explained below according to examples.

"Example 1" FIG. 1 shows the circuit of the invention.

In the drawing, the picture element (1) is the first diode (2).

The second diodes (3) are connected to each other and the midpoint (25)
It is connected to one electrode of the liquid crystal (4). Also the first
The diode is at the address '1tfA of the X wiring (5)
, (6), and the other second diode is connected to the data lines (7), (8) of the Y wiring. This X
Both the wiring and the Y wiring are connected to the same light-transmitting insulating substrate, typically a glass substrate ((32
) on the other electrode of the liquid crystal (4) (Fig.
(27) ') in Fig. 2(B) is a glass substrate ((3) in Fig. 2(B)).
1)), and the two coordinates are made to correspond to each other. This Z
The wiring for other uses may be formed on the entire surface, or may be patterned linearly parallel to the X wiring, or may be provided parallel to the Y wiring, each of which is determined depending on the usage.

Such picture elements are arranged in a matrix, 2×2 in the drawing.
And so. This is useful for scaled-up display devices such as (
640 x 525 pixels) is also based on the same technique.

In FIG. 1, writing (W) and saving (S) signals.

If the erase or rewrite (IE) signal is e.g.
If you want to selectively perform only 1, 1), you can do it as shown in the table below.

Thus, a predetermined voltage is selectively applied to (1,1).

By adding it to each Y wiring, you can make the liquid crystal transparent.
1'', and other picture elements could be made into opaque rOJ.

By repeating this selection, it is possible to write, hold, and successfully erase other picture elements. This voltage (■) is generally rONJ rtransparent J when the liquid crystal drive is 2.7V or more, and rOF when it is 1.9V or less.
For example, V=3. It was set as OV. Further, by applying this voltage as an alternating current in synchronization in a matrix system, alternating current driving can be achieved. Furthermore, it is effective to set the Z-axis voltage to V/2±ΔV and vary this voltage to create gradations.

"Example 2" This example is shown in Fig. 2, its plan view (A) and longitudinal sectional view (
[1] (C) is shown. FIG. 2(C) shows only a cross-sectional view of the substrate on the side where the lower active element is located for the sake of simplification.

This drawing shows an embodiment of the present invention in which the picture element at address (1.1) in the circuit of FIG. 1 is patterned.

In the drawing, a non-alkali glass (32) is used as a light-transmitting insulating substrate, and ITO is applied to the top surface by sputtering.
Alternatively, a tin oxide film was formed to a thickness of 0.1 to 0.4 μm. Thereafter, this transparent conductive film is patterned to form pixels. Liquid crystal electrode (26), X direction wiring (5
) and lower pads (37) and (38) for diodes (2) and (3) were formed by removing unnecessary portions using a first photomask.

After this, the lower metal film is coated with chromium 500~ on all these surfaces.
The film was formed to a thickness of 1,500 mm, and a diode having a PIN structure doped with hydrogen or a halogen element was formed by a plasma vapor phase reaction method. That is, P-type semiconductor (46
) is the electrical conductivity of the microcrystal 1o-1~1゜1 (Ωcm)-
'The thickness was 300 to 300 people. Further, an I-type semiconductor (35) was formed to a thickness of 0.5 to 1 .mu. by a silane plasma vapor phase method. Furthermore, N-type semiconductor (34)
has a microcrystalline structure, and its electrical conductivity is 10' to 102 (
Ωcm)-' and a thickness of 30 to 100 mm.

Thereafter, except for the pads provided as a pair of diodes (2) and (3), the remaining portions were removed by photo-etching using a second photomask.

Next, a silicon oxide film (33) was formed as an interlayer insulator to a thickness of 0.3 to 0.5 .mu.m by plasma vapor deposition, and the third mask was used to remove the portion marked with ■ and the remaining portions.

Furthermore, wiring in the Y direction was formed. In addition, connection (40) between the upper electrode of the first diode and the electrode (26) of the liquid crystal
, and the upper electrode of the second diode (3) and the Y-axis wiring (
7) and the connection (41) was formed by the fourth mask (3).

From the above, it is possible to form one active picture element on this surface by using only four types of photomasks, and furthermore, only two contacts are required, one for each diode. has.

Furthermore, the lower side of the diode was shielded from light with chromium to prevent the active film diode I from being irradiated with light.

As for the display panel, wiring was then processed, another opposing substrate (31) was separated by a width of about 10μ, the gap was evacuated, and then a known liquid crystal (4) was sealed.

In this way, it has become possible to further pattern the contact portion with two pieces/picture element using only four masks.

“Example 3j The circuit of this embodiment is shown in FIG.

In the drawings, the basic structure is the same as in FIGS. 1 and 2.

However, in Fig. 3, the other electrode side of the liquid crystal (the substrate (31) and the lower electrode (27) in Fig. 2) are connected in the X or Y direction (X direction in the drawing) by three wires. and they are (11-1, 11-2, 1l-3)
Alternatively, it is provided as the Z axis of (12-1, 12-2, 12-3).

In addition, R(13), G(
14), B (15) (7) Color filter (1
0) is provided. Traditionally, full color one-sided format was used as IGF.
If this were to be carried out using , one IGF would be required for each picture element of this filter. However, in the present invention, only one picture element (1) is required for each of R, G, and B, and this filter may also be of a dot type, and can be provided in a line corresponding to the Z axis, so that it is substantially In other words, the number of active elements required for 173 can be reduced.

In addition, another feature is that the Z-axis decoder (22) can also control the gradation for each picture element.

The driving mechanism for applying voltages rONJ rOFF J of the liquid crystal to each picture element is the same as in the first embodiment.

Further, the manufacturing process as a semiconductor device is the same as in the second embodiment.

"Effects" As described above, the present invention uses diodes to construct an active matrix. Therefore, patterning can be performed with a very small number of masks (4 masks), and the manufacturing yield can be improved.

Since the forward characteristics of a diode are used, there is little variation in the process.

Since the liquid crystal is connected from the midpoint of the two diodes,
It is characterized by easy gradation control.

[Brief explanation of drawings]

1 and 2 are a circuit diagram and a structural diagram of a liquid crystal display panel according to the present invention. FIG. 3 shows another example of the circuit of the present invention. 7t ■

Claims (1)

[Claims] 1. In a macrox configuration in which a plurality of wirings in the X direction and wirings in the Y direction are provided on the same substrate, a non-single crystal to which hydrogen or a halogen element is added is connected to one wiring. A first diode made of a semiconductor, and a second diode connected in the same direction as the first diode and having the same structure, the diode is connected to the other wiring, and the second diode is connected in the same direction as the first diode. A solid-state display device, characterized in that one electrode for liquid crystal display is connected to the middle point where the second diode and the second diode are connected to each other. 2. Forming a pair of pads on which wiring in the X direction, electrodes for liquid crystal display, and diodes are provided using a transparent conductive film provided on a transparent insulating substrate; A step of forming a pair of diodes doped with hydrogen or a halogen element having a PIN junction, a step of forming contact openings on the pair of diodes after forming an interlayer insulator, and a step of forming a second conductive film. selectively forming a wiring in the Y direction, connecting the first diode to the liquid crystal display electrode, and connecting the second diode to the wiring in the Y direction; Characteristic solid-state display manufacturing method. 3. A solid-state display device according to claim 1, characterized in that the diode has a PIN junction with a non-transparent conductive film provided on the lower surface thereof.