Disclosed is a process for fabricating a semiconductor device, which efficiently suppresses a damage layer formed on a base silicon substrate or an interconnection layer and removes a high resistivity layer in the formation of a contact hole, thereby reducing a contact resistance. The contact hole is formed in an etching step of reducing ion energy and an oxygen flow rate as an etching depth progresses, thereby suppressing the damage layer formed on the base. The reduction of the contact resistance is achieved by using a step of removing the high resistivity layer using hydrogen or a hydrogen-containing gas plasma.