Copper dry etching with Cl2/Ar plasma chemistry

Etch rates greater than or equal to 5000 Angstrom min(-1) were obtained for Cu in electron cyclotron resonance Cl-2/Ar discharges at a sample temperature of 200 degrees C for ion-neutral ratios greater than or equal to 0.02. The rates are a strong function of ion-neutral ratio, ion flux, and ion energy through the need to have CuClx desorption rate faster than the CuClx generation rate in order to avoid formation of a chlorinated selvedge layer. Postetch, in situ H-2 plasma cleaning removes most of the chlorine residues and allows creation of clean, anistropic Cu features.