摘要 |
A method for forming field oxide isolation regions using oxygen implantation is described. An oxidation resistant layer such as silicon nitride is formed on a silicon substrate, and acts as an oxidation mask. An opening is then formed in the nitride layer, where field oxide is desired. In one embodiment of the invention, oxygen is implanted into this opening, followed by thermal oxidation. In a second embodiment of the invention, the opening is thermally oxidized, followed by a deep oxygen implant and anneal. Encroachment of the field oxide under the nitride layer is decreased, resulting in a minimum "birds' beak" length.
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