Contact Failures due to Polymer Films Formed during Via-Hole Etching

Abstract
The contact resistance between the first metal and the second metal for double-level metallization was increased due to the polymer film formed during via-hole etching with C2F6/CHF3 plasma. The resistance increases with increasing over-etching time and etching pressure, or with decreasing electrode temperature for the via-hole etching. A Si-coated electrode is more effective in reducing the contact resistance than a carbon electrode is. Furnace heating at 380°C as a post-treatment is very effective in removing the etching polymer and in decreasing the contact resistance.