Effect of Ge profile on the frequency response of a SiGe pFET on sapphire technology

Abstract

We investigate the dc and microwave properties of a SiGe pFET on sapphire technology. The results show that both cutoff frequency (f/sub T/) and low-field mobility (/spl mu//sub eff/) of SiGe pFETs improve with the integrated Ge dose in the SiGe channel, when compared to the Si pFET. Silicon CMOS on sapphire (Al/sub 2/O/sub 3/) technology is ideally suited for microwave circuits since it has a low dielectric loss substrate, low noise figure, excellent radiation hardness, and reduced punch-through effects. Recent studies of SiGe CMOS on sapphire technology have shown improvements in pFET mobility and transconductance at 300 K and 77 K, compared to Si. This work focuses on the effects of Ge profile in the SiGe channel on the low field mobility and cutoff frequency of a SiGe pFET on sapphire technology.