Epitaxial wafers and methods and apparatus for improving the flatness of epitaxial wafers

Abstract

This disclosure provides an epitaxial wafer and a method and apparatus for improving the flatness of the epitaxial wafer. The method includes: selecting a plurality of candidate epitaxial deposition temperatures from a set epitaxial deposition temperature range according to a set temperature gradient based on the nanomorphic values ​​of the edge region of the epitaxial layer of the epitaxial wafer; depositing an epitaxial layer on the surface of a substrate wafer based on each candidate epitaxial deposition temperature to obtain an epitaxial wafer corresponding to each candidate epitaxial deposition temperature; determining an epitaxial deposition temperature as a first epitaxial process parameter based on the epitaxial wafers corresponding to all candidate epitaxial deposition temperatures; determining the flow rate of etching gas and the duration of the surface etching stage based on the edge damage of the substrate wafer, and using these as a second epitaxial process parameter; depositing an epitaxial layer on the surface of the substrate wafer according to the first epitaxial process parameter during the epitaxial deposition stage, and introducing etching gas according to the second epitaxial process parameter during the surface etching stage.

Images