Effects of spruttering due to ion irradiation on plasma anisotropic CVD of Cu

This chapter discusses the effects of sputtering due to ion irradiation on plasma anisotropic CVD of copper (Cu). The effects are studied using silicon (Si) substrates with trenches. Cu metallization contributed to scaling down of ultra large scale integration (ULSI), because Cu has a lower resistivity and better electro-migration resistance than aluminum. This chapter describes experimental results regarding deposition and sputtering rates at top, bottom surfaces, and sidewall of trenches. The chapter also discusses the effects of ion irradiation on plasma anisotropic CVD with the accent on roles of sputtering. Sputtering rates on the top and bottom surfaces decrease with increasing R from 0% to 66% and are nearly constant for R = 66-100%. The rate on the top surface is higher than that on the bottom surface. With decreasing the trench width, the deposition rate on the bottom surface increases, while the sputtering rate decreases.