Method for etching a layer on a silicon semiconductor substrate

摘要

A method for selective etching of an SiGe mixed semiconductor layer on a silicon semiconductor substrate by dry chemical etching of the SiGe mixed semiconductor layer with the aid of an etching gas selected from the group including ClF3 and/or ClF5, a gas selected from the group including Cl2 and/or HCl being added to the etching gas.

主权项

1. A method for etching an SiGe mixed semiconductor layer on a silicon semiconductor substrate, the method comprising:
adding a gas, which includes at least one of Cl2 and HCl, to the etching gas, wherein the etching gas includes at least one of ClF3 and ClF5; and dry chemical etching the SiGe mixed semiconductor layer with the aid of the etching gas and the added gas; wherein a ratio of partial pressures of the etching gas to the added gas, which includes at least one of Cl2 and HCl, is in the range of ≧1:5 to ≦5:1, and wherein the etching is a plasma-less etch based on ClF3 or ClF5 and not a plasma etch, so that no plasma reaches a process chamber with the substrate.