Patent ID: 7371623
Filing Date: 2008-05-13
Classification: G02F,H01L

Abstract:
1. A method for manufacturing a semiconductor device comprising: forming first and second crystalline semiconductor films over a substrate having an insulation surface; forming a gate insulation film on said first and second crystalline semiconductor films; forming a first gate electrode over said first crystalline semiconductor film with said gate insulation film interposed therebetween and a second gate electrode over said second crystalline semiconductor film with said gate insulation film interposed therebetween; first doping an N-type impurity by using said first and second gate electrodes as masks; forming a protective film over said first and second gate electrodes and said gate insulation film; forming an insulation film over said protective film; forming a mask partly over said second gate electrode with said insulation film interposed therebetween; anisotropically etching said insulation film to form a side wall on a side surface of said first gate electrode, wherein said insulation film below said mask remains; and second doping said N-type impurity by using said side wall, said remained insulation film, and said first and second gate electrodes as masks, wherein an N-type impurity concentration of said second doping is higher than that of said first doping.