Patent ID: 7235516

Claim:
A method of semiconductor substrate cleaning comprising cleaning a semiconductor substrate with a semiconductor substrate surface cleaning liquid medium while irradiating the semiconductor substrate with ultrasound having a frequency of 0.5 MHz or higher, wherein the semiconductor substrate surface cleaning medium consists essentially of the ingredients (A), (B), (C), and (D), wherein (A) is an ethylene oxide addition type surfactant which has an optionally substituted hydrocarbon group and a polyoxyethylene group in the same molecular structure and in which the ratio of the number of carbon atoms contained in the hydrocarbon group (m) to the number of oxyethylene groups in the polyoxyethylene group (n) is 1.5 or less, wherein ethylene oxide addition type surfactant is selected from the group consisting of at least one polyoxyalkylene alkyl ether, at least one polyoxyalkylene fatty acid ester, at least one polyoxyalkylene alkyl amine, at least one polyoxyalkylene alkyl ether sulfate, and combinations thereof; (B) is an alkali ingredient; (C) is hydrogen peroxide; and (D) is water; wherein the substrate surface cleaning liquid medium has a pH of from 10.5 to 11.5, an ingredient (A) content ranging from 0.0001% to 0.01% by weight, and an ingredient (C) content ranging from 0.01 to 4% by weight.