Etching liquid for TFT (thin film transistor)array substrate copper conductor

Abstract

Provided is an etchant solution for a copper conductor of a TFT array substrate, comprising: a primary oxidant, a secondary oxidant, a chelating agent, an inhibitor, and an additive; the primary oxidant is hydrogen peroxide; the secondary oxidant is phosphoric acid, sulfuric acid, and nitric acid; the chelating agent is an amino compound; the inhibitor is an amino azole compound or a carboxylic acid compound; and the additive is an amine compound containing an amino nitrogen atom and a carboxyl oxygen coordination atom. The etchant solution improves the feature of a short processing window in an etchant solution for a copper conductor, reduces the difficulty of engineering control, increases stability in engineering production and output yield; improves the shelf-time stability, with the etch stability being also maintained during the later shelf-time period; increases the use life (>=5000 ppm), with no significant narrowing of the process window occurring in the later period of the manufacturing; and ensures the performance being relatively stable.

Description

technical field [0001] The invention relates to the field of etching solution, in particular to an etching solution for copper wires of a TFT array substrate. Background technique [0002] A liquid crystal display (LCD, Liquid Crystal Display) has many advantages such as a thin body, power saving, and no radiation, and has been widely used. The existing liquid crystal display device includes a liquid crystal display panel and a backlight module (Backlight Module). Generally, a liquid crystal display panel includes a CF (Color Filter) substrate, a TFT (Thin Film Transistor) array substrate, and a liquid crystal (Liquid Crystal) disposed between the CF substrate and the TFT array substrate. By supplying power to the TFT array substrate or not, the direction of the liquid crystal molecules is controlled, and the light from the backlight module is projected onto the CF substrate to generate a picture. [0003] The performance characteristics and operating characteristics of a ...

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Problems solved by technology

[0007] (1) The etchant generally has a short process window in the process of etching the metal layer, which makes engineering control more difficult and seriously affects the stability and production yield of engineering production;

[0008] (2) At present, the use of copper wire etching solution generally has unstable shelf-time conditions, and it is easy to have disadvantages such as unstable etching performance and reduced process window in the later stage of storage;

[0009] (3) The service life is generally short (≤3000ppm), and the process window narrows and the performance becomes unstable in the later stage of the process, showing defects such as large critical dimension loss (CD loss)

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