Low-field hole mobility of strained Si on (100) Si1−xGex substrate

Abstract
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 cm 2 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.