Wafer fabrication by implanting through protective layer

Abstract From the Canadian patent

Abstract of the Disclosure, Manufacture of bipolar substantially isoplanar integrated circuit structures is accomplished by rearrangement of the conventional masking steps and by the substitution and full integration of implanting methods for diffusion methods. A uniform nitride layer is deposited over the basic structure of epitaxial islands separated by isolation oxide regions thereby passivating and protecting the isolation oxide regions, epitaxial oxide buffer layer and epitaxial layer from environmental contaminants. The nitride layer which forms part of a composite protective layer is maintained in place throughout a major portion of the fully integrated sequential implanting steps …