METHOD FOR FORMING TUNGSTEN PLUG

摘要

PROBLEM TO BE SOLVED: To provide a tungsten plug forming method by which the reliability of a tungsten plug can be improved ideally by forming sufficiently thick tungsten films in via holes. SOLUTION: In a state such that an insulating layer 20 is formed on lower- layer wiring 10 and via holes 30 for connecting upper-layer wiring 50 which is planed to be formed on the insulating layer 20 to the lower-layer wiring 10 are formed into the insulating layer 20, a tungsten film 40 is formed on the insulating layer 20 including the via holes 30 by the CVD method, and a series of treatment for etching the tungsten film 40 to the surface of the insulating layer 20 or its vicinity is repeated.