Patent ID: 7563654

Claim:
A method for manufacturing a semiconductor device, comprising the steps of: defining a trench by etching a field region of a semiconductor substrate having an active region and the field region; forming a flowable insulation layer in the trench to partially fill the trench; forming an isolation structure by depositing a close-packed insulation layer on the flowable insulation layer in the trench to completely fill the trench; etching the close-packed insulation layer and a partial thickness of the flowable insulation layer of the isolation structure to expose a portion of the active region; cleaning the resultant substrate having the exposed portion of the active region; forming spacers on etched portions of the flowable insulation layer on which bowing occurs along the etched portions of the flowable insulation layer during the cleaning step; and forming gates on the active region and on the isolation structure to border the exposed portion of active region.