Patent ID: 6117350
Filing Date: 2000-09-12
Classification: H01L

Abstract:
A method of etching a semiconductor device comprising:contacting a semiconductor device comprising a substrate and an oxide layer present on the substrate with a solution comprising ammonium fluoride, hydrofluoric acid, hydrogen peroxide, and water to etch the semiconductor device such that the etching selectivity of the oxide layer relative to the substrate ranges from 0.5 to 3, and wherein the etching solution is formed by the process of mixing a first solution comprising ammonium fluoride, hydrofluoric acid, and water with a second solution comprising hydrogen peroxide and water to form the etching solution, the weight ratio of the hydrogen peroxide to water in the second solution being 3 to 7, and wherein during the step of mixing the first and second solutions, the volume ratio of the first solution to the second solution is no greater than 1/25.