Patent ID: 7265025
Filing Date: 2007-09-04
Classification: H01L

Abstract:
1. A method for filling a trench formed in a semiconductor body, the method comprising: performing a first deposition process to coat the trench with a first filling layer with high conformity and minimal roughness; depositing a filling auxiliary layer over the first filling layer; performing a V etch that reaches down to a predetermined depth of the trench in order to produce a V-profile, wherein, in order to form the V-profile, a predominantly isotropically acting wet chemical etching step is carried out until the complete removal of the first filling layer on the surface of the semiconductor substrate and wherein a wet chemical etching is subsequently carried out, by which the material of the filling auxiliary layer that has remained in the trench is completely removed again with high selectivity with respect to the first filling layer; and depositing a second filling layer until the trench is completely filled.