Patent ID: 7985638

Claim:
A semiconductor device manufacturing method which forms a MOSFET in an SOI substrate having an insulating layer between a semiconductor substrate layer and a semiconductor layer, said method comprising the steps of: forming a gate oxide film over said semiconductor layer; forming a gate electrode on said gate oxide film; forming sidewalls made of an insulator to cover side surfaces of said gate electrode; ion-implanting into said semiconductor layer on both sides of said gate electrode to form drain/source regions in said semiconductor layer; partially etching said sidewalls to expose upper parts of the side surfaces of said gate electrode; depositing a metal film to cover top surfaces of said drain/source regions, a top surface of said gate electrode and the exposed upper parts of the side surfaces of said gate electrode; performing heat treatment on said SOI substrate to form silicide layers respectively in the surfaces of said gate electrode and said drain/source regions; and before said depositing a metal film, forming a plurality of grooves in the top surface of said gate electrode by etching said gate electrode, wherein in said depositing a metal film, each of said plurality of grooves is filled with said metal film by sputtering.