Hole confinement and its impact on low-frequency noise in SiGe pFETs on sapphire

We present the first investigation of hole confinement and its impact on low frequency noise in SiGe pFETs on sapphire. A secondary g/sub m/ peak observed at low temperatures (85 K) in SiGe pFETs is attributed to hole confinement in the SiGe channel, and is confirmed by 2-D simulations. The measured low frequency (1/f) noise in the SiGe pFETs is observed to be significantly lower than in the Si pFETs, which is partially the result of the band offset between the Si cap and SiGe channel.