Methods for dry etching at low substrate temperatures using gas chemistry including a fluorocarbon gas and a gas including oxygen

摘要

Methods for fabricating semiconductor devices are described, including methods which improve an etching selection ratio of a film to be etched against metal silicide, Si, and photoresist. One method for fabricating a semiconductor device includes the steps of forming Ti silicide films 9a-9c on the gate electrode 3 and the diffusion layers 6 and 7 of source/drain regions, forming an interlayer dielectric film 10 on the Ti silicide films, and dry-etching the interlayer dielectric film to form in the interlayer dielectric film 10 a contact hole 10a located above the gate electrode, and contact holes 10b and 10c located above the diffusion layers of the source/drain regions, wherein etching gas used for the dry-etching is gas including at least fluorocarbon gas and one of O₂ gas and O₃ gas, and the temperature of the semiconductor substrate is 30° C. or lower when the dry-etching is conducted.