A kind of high-precision etching solution for ito conductive film and preparation method thereof

Abstract

The invention relates to a high-precision etching solution for an ITO (Indium Tin Oxide) conductive film and a preparation method for the high-precision etching solution. The high-precision etching solution is prepared from the following ingredients in percentage by weight: 2% to 8% of nitric acid, 2% to 12% of sulfuric acid, 0.01% to 2% of additive and the balance of water, wherein the additive is a mixture of an alkali metal salt and an organic matter, and the organic matter is any selected from a thiourea derivative, hexamethylene tetramine, imidazole, benzotriazole and 2,4,6-trihydroxybenzoic acid. According to the etching solution disclosed by the invention, nitric acid and sulfuric acid serve as main ingredients, the process is simple, the acid concentration is moderate, the etching solution has excellent etching performance on the ITO conductive film, the etching rate is moderate, the etching precision is high, no residue is caused, and thus the requirements of ITO of different thicknesses on etching can be met. Meanwhile, one alkali metal salt and one organic matter are adopted as the additive, so that the etching solution has an excellent etch-resistant effect on lower-layer metal Al or Mo, and the requirements of technical processes and preparation procedures can be excellently met. In addition, the etching solution takes the low-cost sulfuric acid as a raw material, so that the reduction of the cost of the etching solution is facilitated on the basis of meeting the requirements of the technical processes and the preparation procedures.

Description

technical field [0001] The invention relates to the field of wet electronic chemicals, in particular to a high-precision etching solution for ITO conductive thin films and a preparation method thereof. Background technique [0002] Transparent conductive oxides are becoming more and more commercially important, and the most widely used and valuable areas are in the flat panel display manufacturing industry. Currently, the transparent conductive oxide used as an electrode is mainly Indium-tin-oxide (ITO). ITO etchant is widely used in the manufacturing process of ITO transparent electrodes in TFT-LCD industry. The etching of the ITO film is the last process in the manufacture of the TFT pattern Array. After the ITO film is sputtered, a layer of photoresist is covered, the photomask develops the pattern, and the ITO film is etched with an etching solution, and then the photoresist is stripped to form the desired pattern. In addition, with the development of the display indu...

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Problems solved by technology

[0003] In the prior art, CN201510832036.0 discloses an ITO etchant for high-generation flat panels, which uses sulfuric acid / nitric acid / acetic acid as the main system, and the acid content used is relatively high, the etching reaction is violent, and it is difficult to control the etching accuracy, so it is not applicable Due to the small thickness of the ITO film layer, and the cost of the etching solution is high. In addition, the etching solution contains acetic acid. During use, the acetic acid is easy to volatilize and needs to be replenished continuously, which increases the difficulty of the process.

CN200910003907.2 discloses an etchant composition for etching an indium tin oxide layer and an etching method using the same. The etchant composition is mainly composed of sulfuric acid, nitric acid, and an etching control agent, and the etching control agent is mainly potassium Salt, the acid concentration of the etching solution is low, the etching rate is slow, and it is easy to corrode the underlying Mo and Al, which is difficult to meet the process and process requirements

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