Etching solution, etching method, and method for manufacturing an electronic component
AssigneeKabushiki Kaisha Toshiba
InventorsYukako MURAKAMI, Masaaki Hirakawa, Ikio Uematsu
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Abstract
According to one embodiment, an etching solution used for etching of silicon nitride is provided. The etching solution includes phosphoric acid, an acid, silicic acid compound, and water. The phosphoric acid has a first acid dissociation exponent pKa1. The acid has an acid dissociation exponent smaller than the first acid dissociation exponent pKa1. A mass ratio M1/M2 of mass M1 of the phosphoric acid to mass M2 of the acid having the acid dissociation exponent smaller than the first acid dissociation exponent pKa1 is within a range of 0.82 or more and 725 or less.
Claims28
An etching solution used for etching of silicon nitride, comprising:
- phosphoric acid having a first acid dissociation exponent pKa1;
- an acid having an acid dissociation exponent smaller than the first acid dissociation exponent pKa1;
- a silicic acid compound;
- and water,
- wherein a mass ratio M1/M2 of mass M1 of the phosphoric acid to mass M2 of the acid having the acid dissociation exponent smaller than the first acid dissociation exponent pKa1 is within a range of 0.82 or more and 725 or less.
An etching solution used for etching of silicon nitride, the etching solution comprising:
- phosphoric acid having a first acid dissociation exponent pKa1;
- an acid having an acid dissociation exponent smaller than the first acid dissociation exponent pKa;
- a silicic acid compound;
- and water, wherein
- a concentration of the phosphoric acid is 88 mass % or more and 95 mass % or less, a concentration of the acid having the acid dissociation exponent smaller than the first acid dissociation exponent pKa1 is 1 mass % or more and 5 mass % or less, and a concentration of the water is 4 mass % or more and 11 mass % or less.
An etching solution used for etching of silicon nitride, the etching solution comprising:
- phosphoric acid having a first acid dissociation exponent pKa1;
- an acid having an acid dissociation exponent smaller than the first acid dissociation exponent pKa1;
- hexafluorosilicic acid;
- and water.
Dependencies are inferred from the claim text.