Patent ID: 8841187

Claim:
A method for fabricating a semiconductor device comprising steps of: forming, in a substrate, a protrusion having two side cliffs in alignment with two edges of a gate mask pattern, the side cliffs being substantially vertical to a surface of the substrate, the substrate comprising a first portion having a first crystal orientation and a second portion having a second crystal orientation which are laminated in order, wherein the forming comprises removing portions of the first portion other than a portion which is in alignment with the gate mask pattern; forming a dielectric layer on the substrate formed with the protrusion; etching the dielectric layer to have the dielectric layer left only on the side cliffs, as two dielectric walls; and burying the dielectric walls by growing a material of the substrate, wherein a substrate material having the first crystal orientation is grown between the two dielectric walls, and the burying is performed up to a level higher than the upper end of the dielectric walls.