Method of producing epitaxial wafer
AssigneeSumco Corporation
InventorAkira Fukui
Life of this patent
Estimating the term…
Abstract
A method of adjusting conditions for epitaxial growth includes a first measurement step for measuring the thickness profile of a wafer before forming an epitaxial film; a second measurement step for measuring the thickness profile of an epitaxial wafer and the film thickness profile of the epitaxial film after an epitaxial growth step before a polishing step; a third measurement step for measuring the thickness profile of an epitaxial wafer and the film thickness profile of an epitaxial film; and a step for adjusting conditions for epitaxial growth using the thickness profiles and the film thickness profiles measured in the first, second, and third measurement steps.
Claims7
A method of adjusting conditions for obtaining an epitaxial wafer, the method comprising:
- (A) measuring a thickness profile of an adjusting wafer with a flatness measurement system before an epitaxial film is formed on a top surface of the adjusting wafer;
- (B) forming an epitaxial film on the top surface of the adjusting wafer to form an adjusting epitaxial wafer;
- (C) measuring a thickness profile of the adjusting epitaxial wafer with the flatness measurement system and a film thickness profile of the epitaxial film with a Fourier transform infrared spectrophotometer after forming the epitaxial film and before polishing the adjusting epitaxial wafer;
- (D) simultaneously polishing a surface of the epitaxial film and a rear surface of the epitaxial wafer after the measuring of (C) to form a polished adjusting epitaxial wafer;
- (E) measuring a thickness profile of the polished adjusting epitaxial wafer with the flatness measurement system and a film thickness profile of the epitaxial film with a Fourier transform infrared spectrophotometer after the polishing of (D);
- (F) adjusting conditions for forming an epitaxial film on a top surface of an other wafer of the same type as the adjusting wafer using the thickness profiles and the film thickness profiles measured in (A), (C), and (E);
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- (G) forming an epitaxial film on the top surface of the other wafer using the adjusted conditions of (F) to obtain an epitaxial wafer having a different epitaxial film thickness profile than the film thickness profile of the epitaxial film measured in (C).
Dependencies are inferred from the claim text.