Carrier Mobility and Resistivity of n- and p-Type Si_xGe_1-x (0.93<x<0.96) Single Crystals

Undoped and impurity-doped single crystals of Si_xGe_1-x alloy with the composition 0.93<x<0.96 were grown by the Czochralski technique. Hall-coefficient measurements of the electron and hole mobilities and the resistivity of the crystal grown were carried out at room temperature with respect to their dependencies on the carrier concentration and were compared with those in Si crystals. The electron and hole mobilities in undoped or lightly impurity-doped SiGe were somewhat lower than those in Si, but in heavily impurity-doped SiGe were comparable to those in Si. The alloy disordered scattering and charged impurity scattering are supposed to govern the carrier transport in undoped or lightly impurity-doped SiGe and in heavily impurity-doped SiGe, respectively. The so-called Irvin's relation between the resistivity and the carrier concentration was evaluated for SiGe alloys with the composition 0.93<x<1.