Strain dependence of hole Hall mobility in compressively strained Ge channel heterostructures

We investigated the strain dependence of hole Hall mobility in compressively strained Ge channel modulation-doped (MOD) heterostructures. It was experimentally demonstrated that hole Hall mobility increased with increasing strain of the Ge channel layer at all temperature regions, irrespective of the channel layer thickness and the growth method of SiGe buffer layers. Maximum hole Hall mobilities of 1640 cm2/V s and 13,400 cm2/V s were obtained at room temperature and 8 K, respectively, when the channel was grown on the SiGe buffer layer with the Ge composition of 53%, corresponding to a compressive strain of as high as 2%.