METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To provide a technique which can improve an operating speed of a semiconductor device having a MISFET by reducing the contact resistance of a polymetal gate. SOLUTION: A method for manufacturing a semiconductor device comprises the steps of processing a silicon nitride film (cap insulating film 7a) deposited on a semiconductor substrate 1, a high melting point metal film 6c and a WN film 6b in a predetermined shape, further removing the polycrystalline silicon film 6a of a part exposed from the WN film 6b of a predetermined shape by etching to a predetermined thickness so as not to expose the gate insulating film 5, then selectively forming sidewall films 8 on the sidewalls of the cap insulating film 7a, the high melting point metal film 6c, the WM film 6b and the polycrystalline silicon film 6a retained on the lower part of the WN film 6b, then removing the polycrystalline silicon film 6a of the part exposed from the sidewall film 8, and then heat treating the semiconductor substrate 1 in an oxidative atmosphere. COPYRIGHT: (C)2004,JPO