Patent ID: 6867137
Filing Date: 2005-03-15
Classification: H01L

Abstract:
1. Fabrication method for a semiconductor structure having a partly filled trench, having the following steps: (a) provision of a semiconductor structure having a trench; (b) filling of the trench with a filling in such a way that the filling projects above a surface of the semiconductor structure by a first height, the filling covering the trench and the periphery of the trench; (c) planarization of the filling in a first etching step in such a way that the filling is essentially planar with the surface of the semiconductor structure; (d) sinking of the filling in the trench in a second etching step by a predetermined depth proceeding from the surface of the semiconductor structure; (e) essentially the same plasma power and the same etchant composition being used for the first and second etching steps; and (f) wherein a planarization of the filling is carried out in a zeroth etching step before the first etching step in such a way that the filling projects above the surface of the semiconductor structure by a second height, the filling covering the trench and the periphery of the trench, the zeroth etching step having a higher etching rate than the first etching step.