DEGRADATION CHARACTERISTICS OF STI AND MESA-ISOLATED THIN-FILM SOI CMOS

I-V degradations of STI (shallow trench isolation) and MESA-isolated S OI are reported for devices with a given threshold voltage design (V-T H approximate to 0.4 V) We show that degradation characteristics of th e STI and MESA SOI are quite different from strain-induced degradation observed in the LOGOS SOI, It is found that the nMOSFET's I-V degrada tion becomes more pronounced while pMOSFET's remain relatively constan t as the silicon thickness (t(si)) is reduced, The reduction of nMOSFE T's drive current is attributed to the mobility degradation as the cha nnel concentration is increased whereas for the pMOSFET's, due to the lesser sensitivity of the hole to the Coulomb scattering, no degradati on is observed.