particular type of scattering mechanism, or have not advanced the theory necessary to describe the experimental result. For example, Costato and Reggiani [4] calculated the mobility of holes for pure p-type silicon in which lattice scattering dominates; Braggins [1] considered nonparabolicity and all the relevant scattering mechanisms with the exception of hole-hole scattering, but he limited his investigation to dopant densities below 5xlO16 cm-3 and low temperatures; Morin and Maita [5] considered wide ranges of temperature and dopant densities, but did not provide a theoretical examination of the data. Recently, Li [17] developed a theoretical model capable of describing the mobility and resistivity of p-type silicon over a wide range of temperatures and dopant densities. This improved model was applied to the case of boron-doped silicon with great success [17]. The improvement in the theory consisted mainly of the inclusion of hole-hole scattering effects, and consideration of the nonparabolic nature of the bands. In this study, Li's model [17] has been improved by including consideration of interband scattering effects on the acoustic phonon scattering mechanism, and has been applied to the study of silicon doped with impurities other than boron.

      With some exceptions [14-16], most of the research in p-type silicon has been conducted withboron as the doping impurity, since boron is the shallowest acceptor in silicon and this material is widely available. A very limited amount of data is available on silicon doped with deeper impurities such as gallium and indium. These dopants, especially indium, are of great interest to modern technology because of their application to photo-detector devices. Curves of resistivity and mobility as functions of dopant density [2,3] have been applied to characterizing boron-doped starting material and diffused boron layers in silicon, and