Patent ID: 9640404
Date: 2017-05-02
CPC Classifications: C23C,H01L

Claim:
1. A method of forming a tungsten film on a substrate having thereon an underlying film by using a tungsten chloride gas as a tungsten source gas and a reduction gas for reducing the tungsten chloride gas, the substrate being accommodated in a chamber maintained under a depressurized atmosphere, the method comprising: forming an initial tungsten film on the underlying film, by sequentially supplying the tungsten chloride gas and the reduction gas into the chamber while supplying a purging gas into the chamber between supply of the tungsten chloride gas and supply of the reduction gas, or by simultaneously supplying the tungsten chloride gas and the reduction gas into the chamber, and forming a main tungsten film on the initial tungsten film by sequentially supplying the tungsten chloride gas and the reduction gas into the chamber while purging an inside of the chamber between supply of the tungsten chloride gas and supply of the reduction gas, wherein a supply amount of the tungsten chloride gas supplied in the forming the initial film is smaller than a supply amount of the tungsten chloride gas supplied in the forming the main tungsten film.