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A cold-wall rapid thermal processor is used for the wet oxidation of the commensurately grown GexSi1−x layers on Si substrates. The rate of oxidation of the GexSi1−x layer is found to be significantly higher than that of pure Si, and the oxidation rate increases with the increase in the Ge content in GexSi1−x layer. The oxidation rate of GexSi1−x appears to decrease with increasing oxidation time for the time-temperature cycles considered here. Employing high-frequency and quasi-static capacitance-voltage measurements, it is found that a fixed negative oxide charge density in the range of 1011– 1012/cm2 and the interface trap level density (in the mid-gap region) of about 1012/cm2 eV are present. Further, the density of this fixed interface charge at the SiO2/GeSi interface is found to increase with the Ge concentration in the commensurately grown GeSi layers.

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.

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