Semiconductor device manufacturing method for a copper connection

Abstract

In a semiconductor device manufacturing method, an interlevel insulating film is formed on a silicon substrate. A trench is formed in the interlevel insulating film. A lower underlying film made of a tungsten-based material is formed by thermal chemical vapor deposition to cover a bottom surface and side surface of the trench. An upper underlying film made of a tungsten-based material is formed by thermal chemical vapor deposition on an entire region on the lower underlying film. A copper film made of copper fills the trench. The upper underlying film is formed in accordance with thermal chemical vapor deposition by supplying a tungsten source gas and the other source gas such that the other source gas is supplied in an amount lager than that of the tungsten source gas. The lower underlying film is formed in accordance with thermal chemical vapor deposition by increasing a content of the tungsten source gas to be larger than to that of the other source gas in formation of the lower underlying film.

Dependencies are inferred from the claim text.