Thin film transistor array panel for liquid crystal display and making method thereof

Abstract

A gate wire is formed on an insulating substrate by a photolithography process using the first mask, and a gate insulating layer and a semiconductor layer are sequentially deposited. Then, an ohmic contact layer made of silicide or microcrystallized and doped amorphous silicon is formed on the semiconductor layer. Then, a triple pattern including a gate insulating layer, a semiconductor layer and an ohmic contact layer are patterned at the same time by a photolithography process using the second mask. At this time, a contact hole exposing the gate pad is formed. An ITO layer and a metal layer are deposited and patterned to form a data wire, a pixel electrode, and a redundant gate pad by a photolithography process using the third mask. The ohmic contact layer, which is not covered with the ITO layer and the metal layer, is removed. A passivation layer is deposited and patterned by a photolithography process using the fourth mask. Next, the metal layer of the pixel electrode, the redundant gate pad, and the data pad, which is not covered with the passivation layer, is removed. At this time, the semiconductor layer that is not covered with the passivation layer is removed to separate the semiconductor layer under the neighboring the data lines.

Description

technical field [0001] The invention relates to a thin film transistor (TFT) array panel for a liquid crystal display (LCD) and a manufacturing method thereof. Background technique [0002] A liquid crystal display is currently the most widely used flat panel display device, which is composed of two panels with two types of electrodes for generating an electric field and a liquid crystal layer between the two panels. The transmittance of incident light is controlled by the intensity of the electric field applied to the liquid crystal layer. [0003] The electrodes for generating the electric field are arranged on two or any one of the panels, and one of the panels has at least one electrode, which has a switching element such as a thin film transistor (TFT). [0004] Generally, a TFT array panel of an LCD includes a plurality of pixel electrodes and TFTs for controlling signals supplied to the pixel electrodes. The TFT array panel is made by photolithography using a plural...

AI Technical Summary

Problems solved by technology

The storage electrode is covered by a gate insulating layer, a semiconductor layer and a passivation layer, and most of the pixel electrodes are directly formed on the substrate, as described by Han et al., so the pixel electrodes should be stepped in order to cover the storage electrodes Covered on the three layers of gate insulating layer, semiconductor layer and passivation layer, however, this may cause disconnection of the pixel electrode near the high-level

[0007] The problem with Han et al. is that it is difficult to make in a large area, and even if it can be made, it is difficult to have a uniform etch depth under the bar area

[0008] U.S. Patent No. 4,231,811, No. 5,618,643, No. 4,415,262 and Japanese Patent Publication, No. Showa 61-181130, etc., also disclose methods similar to those of Han et al., but they all have problems similar to those of Han et al.

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