Deep-submicrometer CMOS technology with reoxidized or annealed nitrided-oxide gate dielectrics prepared by rapid thermal processing

摘要

Deep submicrometer CMOSFETs with re-annealed nitride-oxide gate dielectrics have been demonstrated to satisfy 3.3-V operation, unlike conventional oxide FETs. The 1/4- mu m re-annealed nitrided-oxide CMOS devices achieve (1) an improved saturation transconductance g/sub m/ of approximately 250 mu S/ mu m for n-FETs together with acceptably small degradation in p-FET g/sub m/ resulting in a CMOS gate delay time of 55 ps/stage comparable or superior to the device/circuit performance of oxide FETs, and (2) device lifetimes improved by approximately 100 times to exceed 10 years with respect to both ON- and OFF-state hot-carrier reliability for n-FETs as well as gate-dielectric integrity together with unchanged p-FET hot-carrier reliability, all at 3.3-V operation. To achieve these CMOS performance/reliability improvements, both a light nitridation and subsequent re-annealing in O/sub 2/ (reoxidation) or in N/sub 2/ (inert-annealing) are found to be crucial.