METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To improve the performance and manufacturing yield of a semiconductor device.SOLUTION: A sidewall spacer SW composed of insulating films IL2, IL3 is formed on a sidewall of a gate electrode GE by etching back the insulating films IL2, IL3 after sequentially forming the insulating films IL2, IL3 so as to cover the gate electrode GE on a semiconductor substrate SB. Then, a source-drain region SD is formed in the semiconductor substrate SB by injecting ions using the gate electrode GE and the wall spacer SW as masks. Then, the thickness of the sidewall spacer SW is reduced by isotropically etching the sidewall spacer SW under a condition where the insulating film IL2 is more hardly etched than the insulating film IL3. Thereafter, a reactive layer formed by reaction between metal and the source-drain region SD is formed in the source-drain region SD.