Method for manufacturing semiconductor device

摘要

A method for forming a groove in a semiconductor substrate is disclosed. The groove is formed in two steps. In the first step, a first shallow groove is formed in the semiconductor substrate and then a first mask pattern is selectively formed on the wall of the first groove. A second groove is formed in the bottom surface of the first groove using the first mask pattern as a mask. Subsequently the first mask is etched off. The obtained groove may be buried with an insulating material or an electrode material.