Degradation characteristics of STI and MESA-isolated thin-film SOI CMOS

I-V degradations of STI (shallow trench isolation) and MESA-isolated SOI are reported for devices with a given threshold voltage design (V/sub TH//spl ap/0.4 V). We show that degradation characteristics of the STI and MESA SOI are quite different from strain-induced degradation observed in LOCOS SOI. It is found that the nMOSFET´s I-V degradation becomes more pronounced while pMOSFETs remain relatively constant as the silicon thickness (t/sub si/) is reduced. The reduction of nMOSFET´s drive current is attributed to the mobility degradation as the channel concentration is increased, whereas for the pMOSFETs, due to the lesser sensitivity of the hole to the Coulomb scattering, no degradation is observed.