Effect of Strain on the Carrier Mobility in Heavily Dopedp-Type Si

We present an experiment that gives insight into the origin of the dependence of the hole mobility ($\mu$) on the dopant species in heavily doped $p$-type Si under low electrical field. The Hall carrier concentration and mobility were measured in Si coimplanted with B and Ga in the $0.1–2\times {10}^{20}{\mathrm{cm}}^{-3}$ concentration range. The strain induced by substitutional dopants, detected by high resolution x-ray diffraction, was varied by changing the relative B and Ga concentration. The effect of strain on mobility was disentangled and a linear relationship between $1/\mu$ and the perpendicular strain was found.