Reducing parasitic capacitance of strained Si nano p-MOSFET by control of virtual substrate doping

Biaxially strained Si channel p-MOSFETs on virtual SiGe substrates suffer from a parasitic parallel channelin virtual substrate. This channel participates in current passing through the devices and increases parasitic capacitorswhich degrades the high frequency response. In this paper a new approach has been introduced to eliminate the channelwhich in turn reduces parasitic capacitors of the MOSFET. It is illustrated that, increasing virtual substrate doping, canreduce and finally eliminate this unintentional channel. In this work TCAD has been used to investigate the impact ofthe proposed method.

Keywords:

biaxially strained Si p-MOSFET , relaxed , virtual substrate , quantum well , parasitic capacitors