Patent ID: 11875997
Assignee: ENTEGRIS, INC.
Field: Semiconductors (Electrical engineering)
Classification: CPC H  C | IPC C  H

Claim 0:
1. A method of selectively removing silicon-germanium from a surface of a microelectronic device relative to a silicon-containing material, the method comprising:
providing a microelectronic device surface that includes silicon and silicon-germanium,
wherein the silicon-germanium has a formula: Six:Gey, wherein x is in a range from about 0.70 to 0.90, and y is in a range from about 0.10 to about 0.30, with x+y=1.00,
providing an aqueous etching composition comprising:
from 0.1 to 10 parts by weight hydrogen fluoride,
from 10 to 35 parts by weight dissolved hydrogen peroxide,
from 5 to 50 parts by weight dissolved acetic acid,
from 2 to 40 parts by weight dissolved formic acid,
from 0.1 to 10 parts by weight dissolved sulfuric acid, and

from more than 10 to 20 parts by weight dissolved lactic acid per 100 parts by weight dissolved material in the etching composition,
wherein the aqueous etching composition is provided by combining the hydrogen fluoride, acetic acid, formic acid, sulfuric acid, and optional lactic acid to form a solution followed by combining the hydrogen peroxide and the solution to form the aqueous etching composition; and
contacting the surface with the silicon-germanium-selective etching composition for time and at a temperature effective to selectively remove silicon-germanium relative to the silicon.