Detection by Auger Electron Spectroscopy and Removal by Ozonization of Photoresist Residues

Surface chemical analyses by Auger electron spectroscopy (AES) indicate that hydrocarbon residues are frequent contaminants on gold hybrid microcircuit metallization. The primary electron beam for AES cracks the hydrocarbon contaminants causing a carbonaceous residue. Lead frame bonding data demonstrated that a carbon residue approxi-mately 10 A thick was indicative of thermo-compression bond degradation. Concentrations of two percent ozone in oxygen can remove a photoresist layer approximately 200 A thick in 100 hours at room temperature. This restores thermocompression bondability of gold surfaces.