Electrical properties of lightly doped p-type silicon-germanium single crystals

Experimental results are presented on the electrical properties of lightly baron doped bulk Si1-xGex as a function of the Ge content x in the range 0<x<0.13. Calculations of the hole mobility in Si and in Si1-xGex and comparison with experimental results allow us to estimate the averaged scattering potential of the randomly distributed Ge atoms to be 0.55 eV. From Hall effect and capacitance-voltage measurements, a Hall factor around 0.8 at T=300 K is derived. Hall effect measurements in the temperature range 20-300 K enable us to determine the boron acceptor activation energy, which decreases from 45 meV at x=0 down to 32 meV for x=0.13, and to estimate the hole effective masses to be m(eff)/m(0) approximate to 0.45. (C) 1998 American Institute of Physics.