HF Etchant Solutions in Supercritical Carbon Dioxide for “Dry” Etch Processing of Microelectronic Devices

Abstract

A “dry” supercritical CO2-based etchant solution containing HF/pyridine as an anhydrous HF source effectively dissolves SiO2 thin films on silicon wafers. These dilute etchant solutions are active in removal of post-etch residues in back-end-of-line cleaning of microelectronic structures.