W-Ti diffusion preventing film and sputtering target for forming W-Ti diffusion preventing film

摘要

PROBLEM TO BE SOLVED: To provide a W-Ti based diffusion preventing film formed between an Au bump and an Al electrode for mounting a semiconductor chip on a substrate to prevent diffusion of Au and Al and having an excellent diffusion barrier property and a high etching rate, as well as a W-Ti target for sputtering to form the high etching rate W-Ti based diffusion preventing film.SOLUTION: The W-Ti based diffusion preventing film contains Ti: 5-20 wt.%, Fe: 15-25 ppm, and Cr: 1-5 ppm, with the balance consisting of W and inevitable impurities. The sputtering target for forming the W-Ti based diffusion preventing film having the same composition is also provided.