Patent ID: 11920257
Assignee: SUMCO CORPORATION
Field: Measurement (Instruments)
Classification: CPC C  G  H | IPC C  G  H

Claim 9:
10. A method of manufacturing a silicon wafer, the method comprising:
evaluating cleanliness of a member having a silicon carbide surface by a method comprising:
bringing the silicon carbide surface into contact with a mixed acid of hydrofluoric acid, hydrochloric acid, and nitric acid;
concentrating the mixed acid brought into contact with the silicon carbide surface by heating to obtain a concentrated liquid;
adding a solution to the concentrated liquid to obtain a sample solution;
performing quantitative analysis of metal components present in the sample solution by Inductively Coupled Plasma-Mass Spectrometry; and
evaluating the cleanliness of the member having the silicon carbide surface on the basis of a quantitative result of the metal components obtained by the quantitative analysis; and

manufacturing the silicon wafer through a manufacturing process that uses the member whose cleanliness has been determined to be within an allowable level as a result of the evaluation.