Method for fabricating a semiconductor device including the use of a compound containing silicon and nitrogen to form an insulation film of sin or sicn

Abstract

The semiconductor device fabrication method comprises the step of forming gate electrodeon a semiconductor substratewith a gate insulation filmformed therebetween; the step of implanting dopants in the semiconductor substratewith the gate electrodeas the mask to form dopant diffused regions; the step of forming a silicon oxide filmon the semiconductor substrate, covering the gate electrodes; anisotropically etching the silicon oxide filmto form sidewall spacersincluding the silicon oxide filmon the side walls of the gate electrode. In the step of forming a silicon oxide film, the silicon oxide filmis formed by thermal CVD at a 500–580° C. film forming temperature, using bis(tertiary-butylamino)silane and oxygen as raw materials. Silicon oxide filmis formed at a relatively low film forming temperature, whereby the diffusion of the dopant in the doapnt diffused regionsforming the shallow region of the extension source/drain structure can be suppressed.