MINORITY-CARRIER DIFFUSION-COEFFICIENTS IN HIGHLY DOPED SILICON

Direct experimental determination of minority-carrier mobilities and corresponding diffusion coefficients in highly doped p- and n-type silicon have apparently not been performed until now. We have determined the minority-carrier diffusion coefficient in phosphorus- and boron-doped silicon (doping range 1017-1019 cm-3) at 300 K by measuring the complex diffusion length of minority carriers generated by 10.7-MHz optical excitation. Converted into mobilities by the Einstein relation, the results do not differ significantly from Irvin's majority-carrier mobilities.