Method of manufacturing semiconductor device having SOI structure

摘要

The present invention aims to provide a method of manufacturing a semiconductor device having an SOI structure, which is capable of setting an etching process so as to cause contact etching to widely have a process margin even in a semiconductor elemental device using an extra-thin SOI layer. The present method is a method of manufacturing a fully depleted-SOI device. A cobalt layer is formed on an SOI layer. Cobalt is transformed into a cobalt silicide layer by heat treatment. An interlayer insulating film is formed on the cobalt silicide layer, and a contact hole is defined in the interlayer insulating film by dry etching. As an etching gas used in such a dry etching step, a CHF3/CO gas is used. An etching condition is set through the use of a dry etching rate held substantially constant by use of the etching gas. Described specifically, etching time is suitable set.