Si1-x-yGexCy-channel p-MOSFET's with improved thermal stability

We report the fabrication of heterostructure Si1-x-yGexCy channel p-MOSFET' s with low-carbon Si1-x-yGexCy channels. The use of low carbon mole fractio n (y = 0.002) has only a small effect (<<kT) on the valence band offset. A carbon mole fraction of this value dues improve the thermal stability of th e channel region and make it possible to use conventional thermal oxidation and ion implant annealing without causing layer relaxation, A peak room-te mperature hole mobility of 200 cm(2)/Vs was measured in a device with a 30- nm channel and a germanium mole fraction ramped from 10% to 40%.