Patent ID: 7736974

Claim:
A method for manufacturing a semiconductor device, comprising the steps of: forming patterns on a semiconductor substrate having sidewalls and an upper surface; forming a spacer layer, an oxidation promotion layer, and a buffer layer in sequence on the semiconductor substrate including surfaces of the patterns; forming an insulation layer on the buffer layer to fill the patterns, wherein the insulation layer is formed to directly contact the buffer layer; and annealing the semiconductor substrate formed with the insulation layer to oxidize the buffer layer and bake the insulation layer, such that the oxidation of the buffer layer occurs on both surfaces thereof that contact the insulation layer and the oxidation promotion layer, wherein, through the annealing step, the volume of the insulation layer decreases and the volume of an oxidized buffer layer increases, such that the oxidized buffer layer serves to compensate for the decrease in the volume of the insulation layer.