LOW-FIELD HOLE MOBILITY OF STRAINED SI ON (100) SI1-XGEX SUBSTRATE

Strain Hamiltonian and k.p theory are employed to calculate low-field hole mobility of strained Si layers on (100)Si1-xGex substrate. Nonparabolicity and the warped nature of the valence bands are included. At room temperature, in-plane hole mobilities of strained Si are found to be 1103 and 2747 cm2 V-1 s-1 for x equal to 0.1 and 0.2, respectively. These hole mobilities are, respectively, 2.4 and 6 times higher than that of bulk Si. This improvement in the mobility results is mainly due to the large splitting energy between the occupied light-hole band and the empty heavy-hole band and smaller effective mass. The effect of p-type doping on mobility is also presented.