Comparative study of low frequency noise and hot-carrier reliability in SiGe PD SOI pMOSFETs

The stress effect of SiGe pMOSFETs has been investigated to understand the electrical properties of devices fabricated on the Si bulk and PD SOI substrates. A comparison of the drain saturation current (ID.sat) and maximum transconductance (gm,max) in both the SiGe bulk and the SiGe PD SOI devices clearly shows that the SiGe PD SOI is more immune from hot-carriers than the SiGe bulk. The stress-induced leakage current (SILC) is hardly detectable in ultra-thin oxide, because the increasing contribution of direct tunneling is comparable to the trap-assisted component. The SiGe PD SOI revealed degraded properties being mainly associated with the detrimental silicon-oxide interface states of the SOI structure.