ETCHING OF LAYER CONTAINING SILICON DIOXIDE FORMED ON SEMICONDUCTOR SUBSTRATE, IMPROVEMENT OF OXIDE-NITRIDE ETCH SELECTIVITY IN ETCHING OF LAYER CONTAINING BOROPHOSPHOSILICATE GLASS, AND DRAM

PROBLEM TO BE SOLVED: To suppress metal contamination in a layer containing silicon dioxide and prevent electric short-circuits near a contact hole due to carelessness, when etching a semiconductor substrate through a layer containing silicon dioxide formed on the semiconductor substrate in a plasma treatment chamber in the manufacture of an integrated circuit. SOLUTION: In this method, a substrate is placed in a plasma treatment chamber, and then an etchant source gas is poured into the chamber. The etchant source gas contains C4 F8 and added gases other than carbon monoxide (CO) and the added gases contains molecules having both oxygen atoms and carbon atoms. Then, plasma is generated from the etchant source gas, and the substrate is etched at least partially through a layer, including a silicon dioxide.