Abstract: The invention is a process of fabricating semiconductor devices including an insulating film across the surface that has a planar configuration. Alternatively, the film may be of uniform thickness and non-planar configuration. Both the planar and uniform thickness characteristics of the insulating film permit openings to be formed therein without over etching a defined surface area and conductors to be formed thereon without broadening. An important feature of the invention is utilizing the differential growth rate of films on semiconductor surfaces and/or selection of a suitable initial film thickness as a diffusion mask. The initial film thickness also contributes to a planar or uniform film thickness or other configuration across the device.