Measurement of hole mobility in heavily doped n-type silicon

Accurate measurements of the mobility (and diffusion coefficient) of minority-carrier holes in Si:P with doping in the 10¹⁹cm^-3range have been done. The technique employed the measurement of diffusion length by means of lateral bipolar transistors of varied base widths, and the measurement of minority-carrier lifetime on the same wafers from the time decay of luminescence radiation after excitation with a short laser pulse. Minority-carrier hole mobility is found to be about a factor of two higher than the mobility of holes as majority carriers in p-type Si of identical doping levels.