DE2718894

A method of manufacturing a semiconductor device, in particular a device having two complementary insulated gate field effect transistors, in which an aperture is provided in a masking layer and in said aperture a zone is diffused in the body from a highly doped layer, in particular a phosphorus glass layer. According to the invention, a thermal oxide layer is formed in the aperture in a first heating step during the diffusion, after which the doping layer is removed without using a mask and while maintaining the thermal oxide layer, and the dopant is then further diffused in a second heating step. The thermal oxide layer serves as a partial masking against the diffusion, as an etchant stopper and in many cases also as a mask against ion implantation.