Patent ID: 10811520

Abstract:
A method for manufacturing a semiconductor device, includes: forming a well region (201) in a semiconductor substrate (200) and forming a channel region (202) in the well region (201), and forming a gate oxide layer (210) and a polysilicon layer (220) on the well region (201); etching a portion of the gate oxide layer (210) and the polysilicon layer (220), and exposing a first opening (221) used for forming a source region and a second opening (223) used for forming a drain region; forming a first dielectric layer (230) and a second dielectric layer (240) on the polysilicon layer (220) and in the first opening (221) and the second opening (223) successively, and forming a source region side wall at a side surface of the first opening (221) and forming a drain region side wall at a side surface of the second opening (223); forming a dielectric oxide layer (250) on the polysilicon layer (220), etching the dielectric oxide layer and retaining the dielectric oxide layer (250) located on the drain region side wall; removing the second dielectric layer (240) in the source region side wall and retaining the first dielectric layer (230) therein.