Uniform durable thin dielectrics prepared by rapid thermal processing in an N/sub 2/O ambient

Thin dielectrics grown on silicon wafers by rapid thermal processing in an N/sub 2/O ambient at temperatures of 1100 degrees C, 1150 degrees C, and 1200 degrees C are discussed. The resulting films, in conjunction with an O/sub 2/ ambient control were characterized by thickness measurements and electrical performance. Dielectrics formed in N/sub 2/O in this temperature range were all superior to that prepared in an O/sub 2/ ambient in terms of interface state generation and flatband voltage shift after constant current stressing. Although all N/sub 2/O prepared samples exhibited similar cross wafer electrical uniformity, higher growth temperatures favored thickness uniformity. The electrical behavior of the N/sub 2/O wafers was not strongly dependent on growth temperature; however, a 60-s 1100 degrees C post-oxynitridation N/sub 2/ anneal was found to significantly reduce subsequent electrical performance. It is also demonstrated that under optimum process conditions, high-quality uniform dielectrics can be formed by RTP in N/sub 2/O.<
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