Patent ID: 7638398
Filing Date: 2009-12-29
Classification: H01L

Abstract:
1. A method for fabricating a semiconductor device, the method comprising: forming first and second trenches in a substrate, the trenches being closer in a minor axial direction than in a major axial direction; etching the substrate underneath the first and second trenches to form a first recess connecting the first and second trenches, wherein etching the substrate underneath the first and second trenches comprises: forming an isolation structure filling the first recess and the first and second trenches; etching a portion of the isolation structure to form a second recess that defines first, second, third and fourth surfaces of an active region, the active region being shorter in the minor axial direction than in the major axial direction; forming a gate insulation layer over the first, second, third, and fourth surfaces of the active region; and forming a gate electrode around the first, second, third, and fourth surfaces of the active region.