JPH03209438A - Electrooptical device - Google Patents

Abstract

PURPOSE:To obtain uniform picture display by changing the composition ratio of a base material corresponding to a resistance value from the terminal part of a wiring electrode. CONSTITUTION:A transparent electrode 32 is defined as a scanning electrode and a wiring electrode 31 is defined as a data electrode and driven by time division drive. A transparent substrate 21 is made of normal glass such as soda glass, etc., and for a transparent picture element electrode 22, an indium tin oxide film (ITO) is deposited to the whole surface of the transparent substrate 21 by a means such as magnetron sputtering and deposition, etc., and next patterned to a prescribed shape by photoetching. Corresponding to the resistance from the terminal part of the wiring electrode 31, the composition ratio of an a-Si base material is changed. Thus, the uniform picture display can be obtained and gradation display and full color can be easily realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrical device having a large number of pixels used in displays for personal computers, displays for hand belt computers, displays for various measuring instruments, televisions, shutters for printers, etc. Related to optical devices.

[Summary of the invention]

The present invention provides an electro-optical device having a switching element such as a nonlinear resistance element or TPT using a-3i as a base material, in which the a-3
By changing the composition ratio of the i-base material, uniform screen display is possible, and gradation display and full-color display are facilitated, thereby making it possible to provide an electro-optical device with high image quality.

[Conventional technology]

We are developing a nonlinear resistance element for electro-optical devices using a silicon nitride film, silicon oxide film, silicon nitride oxide film, or silicon carbide film as a nonlinear resistance element, or a-SiTF.
We have developed T.

These a-3i base films have been formed with as uniform a composition as possible on the upper surface of the same substrate using a plasma CVD device or a sputtering device.

[Problem to be solved by the invention]

In recent years, as electro-optical devices using liquid crystals have become larger in capacity and have higher image quality, it has become essential to lengthen and miniaturize wiring electrodes. The resistance of a wiring electrode increases in proportion to the distance from the terminal portion, and its value increases as the width of the electrode becomes narrower and longer. This causes a voltage drop due to the rounding of the scanning waveform and data waveform, which causes display unevenness within the screen.

The present invention provides a uniform screen display by changing the composition ratio of the a-3i base material in accordance with the resistance value from the terminal part of the wiring electrode in an electro-optical device having a switching element using a-3i as the base material. It is designed so that you can obtain

[Means to solve the problem]

The electro-optical device of the present invention solves the above problems, and in an electro-optical device using a switching element using a-8i as a base material, the a-3i The composition ratio of the base material is changed.

[Effect]

As mentioned above, in an electro-optical device using a switching element using a-Si as a base material, uniform screen display can be achieved by changing the composition ratio of the a-3i base material depending on the resistance from the terminal part of the wiring electrode. At the same time, gradation display and full-color display become easy, resulting in an electro-optical device with high image quality.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1(A) is a plan view of a pixel electrode structure of an embodiment to which the present invention is applied, and FIG. 1(B) is a sectional view of a nonlinear resistance element.

FIG. 2(A) is a perspective view showing an embodiment of a substrate on which a nonlinear resistance element of a liquid crystal display device according to the present invention is formed;
Only one pixel is shown in an enlarged manner, and the liquid crystal layer, the opposing substrate for sealing the liquid crystal, the deflection plate, etc. are omitted for the sake of simplicity. FIG. 2(B) is a diagram clearly showing one pixel of the vertical cross-sectional structure of the liquid crystal display device according to the present invention.

FIG. 3 shows a circuit diagram of a liquid crystal display device using the nonlinear resistance element of the present invention. In FIG. 3, transparent electrode 3
In this example, 2 is 480 scanning electrodes, and 31 wiring electrodes are 640 delta electrodes, and they are driven by time-division driving of 480 divisions.

In FIG. 2(A), 21 is a transparent substrate, which is made of ordinary glass such as soda glass.

22 is a transparent pixel electrode, made of indium tin oxide HCI
TO) is deposited at about 100 to 500 A over the entire surface of the transparent substrate 21 by means such as magnetron sputtering or vapor deposition, and then patterned into a predetermined shape by photoetching. 24 is an amorphous material whose main component is silicon, and it is reacted by a vertical pass-through magnetron sputtering device using a silicon single crystal or silicon polycrystal target and argon gas containing about 5 to 15% nitrogen gas. A silicon nitride film containing almost no hydrogen was deposited with a thickness of about 500 to 1500 A using a chemical sputtering method. In addition, in this example, as shown in FIG. 4, the direction of board movement is perpendicular to the line of the wiring electrodes, and the diameter of the Nisso gas outlet hole is made larger as it approaches the terminal, or the pitch of the holes is adjusted. The silicon nitride film was formed by reducing the amount of nitrogen closer to the terminal portion so that the amount of nitrogen blown out increased closer to the terminal portion. As a result, the composition of the silicon nitride film became richer in silicon as the distance from the terminal portion increased. A wiring electrode 13 constitutes one of the matrix electrodes.

In this example, aluminum silicon or chromium metal was deposited on the nonlinear resistive thin film 14 at approximately 1000 to 8000 A by continuous magnetron sputtering in the same chamber or in a separate chamber. Next, the metal wiring electrode 13 is patterned into a predetermined shape by photoetching. Thereafter, the nonlinear resistance thin film 14 was patterned into a predetermined shape by photoetching.

FIG. 2(B) is a longitudinal sectional view of a liquid crystal display device according to the present invention. Reference numeral 26 denotes a liquid crystal layer, which has a thickness of 5 to 7 μm and is made of twisted nematic material.

Reference numeral 25 is an alignment film made of polyimide material with consideration of dielectric constant and resistance, and reference numeral 27 is a transparent conductive film (ITO) constituting one electrode group of the matrix electrodes.

Further, 28 is a deflection plate.

When comparing the liquid crystal display device according to the present invention and the conventional liquid crystal display device, there is a noticeable difference in screen display. A voltage drop phenomenon due to resistance appears along the line, and as the drive voltage is gradually increased from 0 volts, the display starts to appear from the terminal area. In particular, in the case where chromium was used as the wiring electrode, there was a difference of 1 to 2 V in voltage level at the beginning of display between the terminal portion and the pixel farthest from the terminal portion.

However, in the liquid crystal display device according to the present invention, even if the voltage drops due to the resistance of the wiring electrodes, the voltage drop is compensated for by changing the composition ratio of the nonlinear resistive thin film and lowering the threshold characteristics of the nonlinear resistive element. Therefore, when the driving voltage was gradually increased from Ov, the screen began to display uniformly throughout.

〔Effect of the invention〕

As explained above, in the electro-optical device according to the present invention,
By changing the composition ratio of the a-3i base material according to the resistance value from the terminal part of the wiring electrode and changing the threshold characteristics of the nonlinear resistance element, a uniform screen display can be obtained.
By facilitating gradation display and full-color display, an electro-optical device with high image quality can be obtained.

[Brief explanation of drawings]

FIG. 1(A) is a plan view of a pixel electrode showing an embodiment of the present invention, FIG. 1(B) is a cross-sectional view of a nonlinear resistance element, and FIG.
) and (B) are respectively a perspective view of the electrode structure of the substrate and a vertical cross-sectional view of the liquid crystal display device, FIG. 3 is a circuit diagram of a liquid crystal display device using a nonlinear resistance element, and FIG. 4 shows an embodiment of the present invention. FIG. 3 is a diagram showing a gas outlet of a pass-through sputtering device. 11.21.41...Transparent substrate 12.22...Transparent pixel electrode 13.24.31...Wiring electrode 14.23...Nonlinear resistance film 15.34...Nonlinear resistance element 25... Alignment film 26. 33... Liquid crystal 27. 32... Transparent electrode 28... Deflection plate

Claims (6)

[Claims] (1) An electro-optical device using a switching element using a-Si as a base material, characterized in that the composition ratio of the a-Si base material is changed depending on the resistance value from the end of the wiring electrode. optical equipment. (2) The inner surface of at least one of the substrates is made up of a wiring electrode, a pixel electrode, and a nonlinear resistance element, and the nonlinear resistance element has a first conductor made of the wiring electrode, and a second conductor made of the pixel electrode, Furthermore, in an electro-optical device comprising a nonlinear resistance film formed between a first conductor and a second conductor, the nonlinear resistance film is made of an a-Si base material, and the resistance value from the terminal portion of the wiring electrode is 2. The electro-optical device according to claim 1, wherein the composition ratio of the nonlinear resistive film is changed accordingly. (3) In the electro-optical device in which the nonlinear resistance film is substantially made of SiNx, the Si composition ratio is increased in proportion to the resistance value from the terminal portion of the wiring electrode. Electro-optical device. (4) The electro-optical device in which the nonlinear resistance film is substantially made of SiOy, wherein the Si composition ratio is increased in proportion to the resistance value from the terminal portion of the wiring electrode. Electro-optical device. (5) The electro-optical device in which the nonlinear resistance film is substantially made of SiNxOy, wherein the Si composition ratio is increased in proportion to the resistance value from the terminal portion of the wiring electrode. Electro-optical device. (6) The electro-optical device according to claim (2), wherein the nonlinear resistance film is substantially made of SiCz, and the Si composition ratio is increased in proportion to the resistance value from the terminal portion of the wiring electrode. Electro-optical device.