Mitsubishi Gas Chemical Company, Inc.

Mari Shigeta

Kunio Yube

Provided is a liquid etching composition that etches an oxide comprising indium, zinc, tin and oxygen at a preferable etching rate, without the etching rate being changed much along with the dissolution of the oxide, and with no substantial generation of deposit, and corrodes wiring materials at such a low level to be ignorable. The present invention uses a liquid etching composition comprising (A) at least one selected from the group consisting of sulfuric acid, methanesulfonic acid, and a salt of any of these acids; and water; the liquid etching composition having a pH value of &#x2212;1 to 3.

Liquid composition for etching oxides comprising indium, zinc, tin, and oxygen and etching method

The present invention provides an etching liquid which has a suitable etching rate for etching of an oxide containing zinc and tin and is suppressed in change of the etching rate due to dissolution of the oxide, while being free from the generation of a precipitate. The corrosiveness of this etching liquid to wiring materials is low enough to be ignored, and this etching liquid has excellent linearity of a pattern shape. The present invention uses an etching liquid which contains (A) one or more substances selected from the group consisting of sulfuric acid, nitric acid, hydrochloric acid, methanesulfonic acid, perchloric acid and salts of these acids, and (B) oxalic acid or a salt thereof and water, and which has a pH of from &#x2212;1 to 1.

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Tokyo, Japan

Mari Shigeta