Patent ID: 8530330

Claim:
A method for manufacturing a semiconductor device, comprising the steps of: defining trenches in isolation regions of a semiconductor substrate having active regions and isolation regions; forming a first insulation layer in a lower portion of the trenches; forming an etch protection layer on surfaces of the trenches that are filled with the first insulation layer and forming an oxide layer on the etch protection layer for preventing the first insulation layer from being etched in a succeeding process; filling a second insulation layer in the trenches that are formed with the etch protection layer, the oxide layer, and the first insulation layer to form an isolation structure in the isolation regions of the semiconductor substrate; and recessing an entire surface of the active regions of the semiconductor substrate such that the isolation structure has a height higher than the active regions of the semiconductor substrate, wherein recessing the portions of the active regions is performed such that the active regions are recessed below a lowermost bottom portion of the etch protection layer, wherein the etch protection layer is formed as a nitride layer.