Furnace nitridation of thermal SiO/sub 2/ in pure N/sub 2/O ambient for ULSI MOS applications

Furnace nitridation of thermal SiO/sub 2/ in pure N/sub 2/O ambient for MOS gate dielectric application is presented. N/sub 2/O-nitrided thermal SiO/sub 2/ shows much tighter distribution in time-dependent dielectric breakdown (TDDB) characteristics than thermal oxide. MOSFETs with gate dielectric prepared by this method show improved initial performance and enhanced device reliability compared to those with thermal gate oxide. These improvements are attributed to the incorporation of a small amount of nitrogen ( approximately 1.5 at.%) at the Si-SiO/sub 2/ interface without introducing H-related species during N/sub 2/O nitridation.<
>