Semiconductor device having improved lamination-structure reliability for buried layers, silicide films and metal films, and a method for forming the same

Abstract

After formation of a connection hole or before deposition of an insulator film, a semiconductor device is placed onto a cathode of a plasma generator. A surface of a metal silicide film such as a silicide of titanium is exposed to a plasma of a nitrogen-containing gas at 550 degrees centigrade or less. As a result of such processing, a barrier compound layer, composed of a compound of nitrogen, oxygen, metal and silicon, is formed at a near-surface region of the metal silicide film of the titanium silicide film. Thereafter, while forming a buried layer from material superior in step coverage such as an Al--Ti compound and an aluminum alloy, reaction between the metal silicide film and the buried layer in a later annealing treatment can be avoided without depositing a barrier metal such as a titanium nitride/nitride film in the connection hole. Accordingly, contact resistance, sheet resistance and junction leakage can be reduced and reliability can be improved.

Dependencies are inferred from the claim text.