Reliability of SiGe Channel MOS

We report extensive experimental results on the Negative Bias Temperature Instability (NBTI) of SiGe channel pMOSFETs as a function of the main gate stack parameters. These results clearly show that this high-mobility channel technology offers a significantly improved NBTI robustness compared to Si-channel devices, which can virtually eliminate this critical reliability issue for sub-1 nm EOT devices. The intrinsically superior NBTI robustness is understood in terms of a favorable energy decoupling between the SiGe channel and the gate dielectric defects. Thanks to this effect, both a significantly reduced time-dependent variability in nanoscaled SiGe devices and a reduced low-frequency noise are also observed. Other reliability mechanisms, such as Channel Hot Carriers and Time-Dependent Dielectric Breakdown are shown not to be showstoppers. All these aspects underscore the SiGe channel technology as a very promising alternative to Si pMOSFETs for future CMOS technology nodes.