MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for fabricating a semiconductor device is to increase the reliability of a device by uniformly maintaining a threshold voltage so that an impurity doped into a polysilicon layer is not diffused into a silicide layer. CONSTITUTION: A field oxide layer(33) is formed on a predetermined part of a semiconductor substrate(31) by a LOCOS(local oxidation of silicon) method. A gate oxide layer(35) is formed by thermal oxidizing the surface of the semiconductor substrate. A polysilicon layer(37) is deposited on the field oxide layer and the gate oxide layer by a CVD(chemical vapor deposition) method. A barrier layer(39) and a silicide layer(41) are deposited on the polysilicon layer by the CVD method and a sputtering method. A gate(43) is formed by patterning the silicide layer, the barrier layer, and the polysilicon layer in this order, using a photolithography method. A low concentration region(45) is formed by ion implanting and annealing N-type impurity ions into the substrate. A sidewall(47) is formed on the side surface of the gate.