SILICON-DOPED TITANIUM WETTING LAYER FOR ALUMINUM PLUG

摘要

PROBLEM TO BE SOLVED: To minimize the formation of reaction products caused by the mutual diffusion between metallic plugs and a wetting layer by forming the wetting layer by coating the side wall of a hole with a silicon-doped titanium film and depositing a material composed mainly of aluminum in the hole. SOLUTION: When a feature 10 is made of a semiconductor material, a barrier layer 14 is optionally deposited so as to cover the bottom section and side wall of a hole. Then a wetting layer 16 is formed for covering the side wall 18 of the hole with a film containing titanium doped with silicon in a Ti:Si molar ration greater than 1:2. The silicon concentration of the wetting layer 16 suitable to inhibit the formation of TiSi2 is about 0.1% to 20% wt. The suitable method for depositing the silicon-doped titanium wetting layer 16 is sputtering deposition using a sputtering target of a material prepared by mixing titanium with silicon at the same mixing ratio as a desired mixing ratio to be taken into the deposited film 16.