Patent ID: 7863151
Filing Date: 2011-01-04
Classification: H01L

Abstract:
1. A method for manufacturing a semiconductor device comprising: (a) forming a lightly doped first epitaxial semiconductor layer of a first conductivity type on a first major surface of a heavily doped semiconductor substrate of the first conductivity type; (b) forming a first mask film for forming a trench on the first major surface and forming a second mask film, comprising a material different from a material of the first mask film, subsequent to forming the first mask film for forming a super-junction structure in the first epitaxial semiconductor layer, the super-junction structure providing a main current path in an ON-state of the semiconductor device, the super-junction structure being depleted in an OFF-state of the semiconductor device, the super-junction structure comprising a columnar first region of the first conductivity type and a columnar second region of a second conductivity type extending in parallel to the main current path, the columnar first region and the columnar second region being arranged alternately and in adjacent to each other; (c) selectively removing a portion of the second mask film in a marker region for mask positioning in a scribe region pattern and a portion of the second mask film in a region outside the scribe region pattern; (d) forming an opening for forming a trench in the first mask film, the trench being necessary for shaping the second region with a column in adjacent to the first region and for arranging the second region and the first region alternately; (e) forming the trench through the opening by etching using the first mask film for an etching mask, the trench having a high aspect ratio; and (f) removing a portion of the first mask film outside a region covered with the second mask film and burying a second epitaxial semiconductor layer of the second conductivity type in the trench for forming the columnar second region and for further forming the super-junction structure.