Patent ID: 7816208
Filing Date: 2010-10-19
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device, comprising: a first step of forming an STI (Shallow Trench Isolation) region includes a first insulating film and an active region surrounded by the STI region on a semiconductor substrate so that an upper end of the first insulating film is lapped on an upper end of the active region and so as to include a shoulder part, the shoulder part having a surface being almost perpendicular to the semiconductor substrate; a second step of forming a second insulating film and a third insulating film in order on an entire surface including the shoulder part; a third step of forming a fourth insulating film on the third insulating film, the fourth insulating film serving as a hard mask when a gate trench is formed; a fourth step of performing a dry etching using the third insulating film as an etch stopper, and forming an opening in the fourth insulating film, the opening corresponding to a width of the gate trench; a fifth step of sequentially removing the third insulating film and the second insulating film exposed to a bottom of the opening; and a sixth step of forming the gate trench in the semiconductor substrate using the fourth insulating film as a part of a mask and the shoulder part of the STI region as another part of the mask, the shoulder part extending in an extension direction of the gate trench, and leaving a thin film part that is a part of the semiconductor substrate between the gate trench and the STI region.