Patent ID: 7163849

Claim:
A fabrication method of a semiconductor integrated circuit device, comprising the steps of: (a) forming an insulating film over a semiconductor wafer; (b) after the step (a), inserting the semiconductor wafer into a thermal chemical vapor deposition chamber of a first film forming apparatus; (c) heating the inside of the chamber; and (d) after the step (c), forming a silicon film added with a conductive impurity over the insulating film by a chemical vapor deposition method, said step (c) comprising the sub-steps of: (c1) heating the inside of the chamber while keeping the inside of the chamber at atmospheric pressure; and (c2) after the sub-step (c1), heating the inside of the chamber while adjusting the pressure inside of the chamber to vacuum or not greater than atmospheric pressure, wherein a time required for the sub-step (c1) is longer than a time required for the sub-step (c2).