Performance and reliability assessment of dual-gate CMOS devices with gate oxide grown on nitrogen implanted Si substrates

In this paper, we have investigated the performance and reliability of dual-gate (N/sup +/-poly for NMOS and P/sup +/-poly for PMOS) CMOS devices with gate oxides grown on nitrogen Implanted Si substrates (NISS). Oxynitride gate dielectrics (28/spl sim/63 /spl Aring/) were fabricated with several nitrogen implantation doses and compared with control SiO/sub 2/ of identical thicknesses. Our results indicate that as gate oxide thickness is scaled down, NISS oxides show improvements over control SiO/sub 2/ in maximum transconductance, subthreshold swing, as well as on- and off-state drain current for both N- and PMOSFETs. Hot-carrier stressing is performed on both NISS and control devices of identical gate oxide thickness (36 /spl Aring/). Compared to control SiO/sub 2/, NISS oxide devices show longer device lifetime and suppressed gate-induced drain leakage (GIDL) current for PMOSFETs under I/sub g,max/ stressing. No difference in NMOSFET degradation (/spl Delta/V/sub t/, /spl Delta/G/sub m/) is observed under I/sub sub,max/ stressing. However, significant degradation under hot hole injection (V/sub g/=V/sub d/) compared to control SiO/sub 2/ is observed in NISS P/sup +/-poly PMOSFETs. In addition, degradation of NISS oxide TDDB is observed.