2D numerical investigation of the impact of compositional grading on the performance of submicrometer Si-SiGe MOSFET's

Computer simulation is used to establish the impact of design parameters on the subthreshold characteristics, hot carrier injection, and high frequency performance of Si-SiGe FET's. The results indicate that by fully grading the Ge content in the channel of a MOSFET, short channel effects are reduced and high frequency performance is improved as compared to devices with uniform Ge channels. A cutoff frequency of 38 GHz and a maximum frequency of oscillation of 160 GHz are predicted for fully graded p-channel MOSFET's with 0.25 /spl mu/m gate lengths. Energy balance simulation reveals that hot carrier injection at the Si-SiO/sub 2/ interface is considerably suppressed if a fully graded channel is employed.>