A process is described for the formation of self‐aligned contacts to the source and drain regions of a silicon insulated‐gate field‐effect transistor by means of nitrogen implantation. It is shown that the nitrogen induces an oxidation delay period during which no oxide growth is observed in the contact regions, but oxidation is not suppressed over the polycrystalline silicon gate if it has been protected from the nitrogen implant. If the contact regions are not covered by silicon dioxide during nitrogen implantation, metallization can be performed immediately after gate oxidation, and the contacts thus formed appear to have good electrical character. However, the thickness of silicon dioxide which can be grown over the gate is limited.
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