CURRENT DISTRIBUTIONS IN SILICON-GERMANIUM P-MOSFETS

Simulations of the current distributions in Si-Ge p-MOSFETs are presen ted for Si-Ce channel designs that have a triangular or a uniform Ge p rofile. The distributions of current show why the triangular design is better than the uniform Ge profile. Contributions to the transconduct ance in both designs are dominated by the Si-Ge channel in the -0.5 to -1.5 V gate-voltage range but the contribution to the device performa nce from the current parallel to the top oxide/Si interface dominates the response by -2.5 V.