Abstract of the Disclosure

A process for selectively etching silicon nitride, chromium, ultra thin silicon dioxide, etc. layers using a thin layer of silicon as a mask against hydrofluoric acid (HF) etchants. Then long diffusions, using indium, gallium, etc. are performed through a selectively etched silicon nitride mask into an underlying semiconductor without mask reprocessing cycles

• Figure 1 is a flow chart illustrating a method embodying the present invention
• Figure 2 is a series of schematic cross-sectional views aligned with the Figure 1 steps to illustrate a structure which may be expected when practicing the method of this invention.
• Figure 3 shows an additional semiconductor structure made according to the methods of this invention.

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