Method of forming structures on a semiconductor including doping profiles using thickness of photoresist

Abstract

A method of forming structures on a semiconductor wafer ( ) by lithographic and subsequent ion implant steps comprises the steps of: deposition of a resist layer ( ) on a surface of said semiconductor wafer ( ), exposing said resist layer to light of a predetermined wavelength through a reticle and an optical system so as to form an image of said reticle on said semiconductor surface, developing and cleansing said surface of said semiconductor wafer ( ) so as to remove at least partly said resist layer ( ) depending on whether or not said resist layer had been exposed, implantation of ions so as to determine the conductivity of said semiconductor in said cleansed areas of said semiconductor surface. In order to allow the preparation of the resist for all doping profiles in a single processing step it is suggested that the surface energy of the resist ( ) vs. the semiconductor ( ) is chosen so as to accomplish a conglomeration of the resist depending on the density of the structures ( ) on the semiconductor surface.