Etch combination

Abstract

The invention provides a etching compound, using said compound to carry out wet etching for TFT grid wiring material Al-Nd / Mo bilaminar membrane or Mo / Al- Nd / Mo three-layer membrane, which forms film transistor liquid crystal displayer, the wet etching employs single process by way of no undercut by lower membrane Al- Nd or Mo; the taper is good and configuration of Mo monolayer film of source / drain wiring material is outstanding. The etching compound comprises phosphoric acid, aqua fortis, acetic acid, acetic acid surface activator and water.

Description

technical field [0001] The present invention relates to the etching composition of metal film for gate electrode and metal film for source / drain electrode of thin-film transistor liquid crystal display device, more specifically, the present invention relates to following etching composition, adopt described composition, can the following Al-Nd or Mo film Al-Nd / Mo double-layer film or Al-Nd / Mo double-layer film or The Mo / Al-Nd / Mo three-layer film is subjected to wet etching, and excellent taper can be obtained, and at the same time, the source / drain wiring material Mo single-layer film can also form an excellent profile. Background technique [0002] The etching process is a process of forming extremely fine circuits on the substrate, and forms the same metal pattern as the photoresist pattern formed by the development process. [0003] The etching process is roughly divided into wet etching and dry etching according to the method. Wet etching uses acid (acid) chemicals to r...

AI Technical Summary

Problems solved by technology

However, the problem is that the equipment is expensive, it is difficult to enlarge the area, and the productivity is lowered due to the slow etching rate.

However, there are problems in that the amount of etchant and pure water used is large, and the amount of waste liquid is large

[0014] However, there is a problem when using the above-mentioned conventional etching composition to etch the Mo film constituting the metal film for the source / drain electrode of the thin-film transistor liquid crystal display device. Poor step coverage of the laminated upper film in the subsequent process

[0015] In addition, if the Al-Nd / Mo double-layer film and the Mo / Al-Nd / Mo three-layer film for the gate electrode of the TFT constituting the thin-film transistor liquid crystal display device are etched with the above-mentioned conventional etchant or etching solution composition , then there is a problem that will produce such as Figure 8 The protrusion phenomenon of the upper Mo film and the undercut phenomenon of the lower Al-Nd or Mo film are shown. The protrusion phenomenon of the upper film must be removed by an additional process, and the undercut phenomenon of the lower film will cause the upper film to be inclined. Disconnection occurs on the surface or the upper and lower metals are short-circuited on the inclined surface

However, if wet etching and dry etching are used at the same time in this way, there are problems of reduced productivity and increased cost due to troublesome processes, which is disadvantageous.

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