Etchant
AssigneeMitsubishi Gas Chemical Company, Inc.
InventorsYouzou Yamada, Toshiyuki Goto
Life of this patent
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Abstract
The present invention provides an etchant less causing damage to IGZOs. The etchant of the present invention comprises hydroxyethanediphosphonic acid (A), one or more phosphonic acids (B), hydrogen peroxide (C), nitric acid (D), a fluorine compound (E), an azole (F), and an alkali (G), and is characterized in that the phosphoric acids (B) comprise one or more phosphonic acids selected from the group consisting of diethylenetriaminepentamethylenephosphonic acid, N,N,N′,N′-ethylenediaminetetrakismethylenephosphonic acid, and aminotrimethylenephosphonic acid and that the proportion of the hydroxyethanediphosphonic acid (A) is in the range of 0.01-0.1 mass % and the proportion of the phosphonic acids (B) is in the range of 0.003-0.04 mass %.
Claims19
An etchant, comprising:
- hydroxyethanediphosphonic acid (A),
- a phosphonic acid (B),
- hydrogen peroxide (C),
- nitric acid (D),
- a fluorine compound (E),
- an azole (F), and
- an alkali (G),
- wherein:
- the phosphonic acid (B) comprises at least one phosphonic acid selected from the group consisting of diethylenetriaminepentamethylenephosphonic acid, N,N,N′,N′-ethylenediaminetetrakismethylenephosphonic acid, and aminotrimethylenephosphonic acid;
- the ratio of the hydroxyethanediphosphonic acid (A) is 0.01 to 0.1% by mass;
- and
- the ratio of the phosphonic acid (B) is 0.003 to 0.04% by mass, each relative to a total mass of the etchant.
Dependencies are inferred from the claim text.