Cobalt silicide fabrication methods that use protective titanium layers

摘要

In a cobalt silicide fabrication process, cobalt is formed on a wafer, then titanium is formed over the cobalt, and the wafer is heated to react the cobalt with the silicon. Then the titanium and the unreacted cobalt are removed. The titanium formed by ionized physical vapor deposition to achieve a good step coverage. In some embodiments, the wafer holding pedestal bias is turned off when the titanium is being deposited.