Patent ID: 7799641
Filing Date: 2010-09-21
Classification: H01L

Abstract:
1. A method for forming a semiconductor device having recess channels, the method comprising: forming first trenches by performing a first etching process using a hard mask film pattern as a mask, and removing the hard mask pattern; forming a barrier film over an entire surface of each of the first trenches and the semiconductor substrate; forming an ion implantation mask film over the barrier film, wherein the ion implantation mask exposes the first trenches; forming an ion implantation mask over the barrier film and over an entire surface of each of the first trenches and the semiconductor substrate, wherein the ion implantation mask exposes the first trenches; forming an ion implantation region in the semiconductor substrate below the first trenches using the ion implantation mask film and the barrier film, wherein the ion implantation region is formed by implanting impurities into the semiconductor substrate at a tilt angle in a range of 5°-7°; forming second trenches below the first trenches by performing a second etching process using the ion implantation mask film and the barrier film as a mask, so that bulb-type trenches for recess channels are formed, each bulb-type trench including the first trench and the second trench; and removing the ion implantation mask film and the barrier film.