the magnitudes of the masses may be substantially different. This difference is not relevant in the study of mobility and resistivity in p-type silicon, but becomes important in the determination of the Hall factor. Since direct experimental verification of values of conductivity and Hall effective masses is not possible, the only way to assess the value of effective mass calculations is by using the theory in the development of directly measurable properties such as resistivity and Hall mobility.
The resistivity analysis for the boron-, gallium-, and indium-doped silicon samples showed agreement between experimental and theoretical results within IQ percent over the entire range of temperature, 100 T 400 K. Note that best agreement between theory and experiment was obtained for boron-doped samples, followed by gallium- and indiumdoped samples. This may be due to the fact that we neglect the compensation effect and the possible dependence of ionization energy on dopant density in the theoretical calculations for gallium- and indium-doped samples. An experimental estimate of degree of compensation was not made for any of the silicon samples studied here. Data points representing a resistivity-dopant density pair are estimated to have a total error of around 6 percent.
A comparison between our calculated mobility values with those of Wagner's [8] data on boron-doped silicon at 300 K shows that agreement is within ±6 percent for NA 3xlO17 cm-3. Discrepancies at higher dopant densities can be eliminated if the effect of deionization of 'boron impurities were included in Wagner's calculations [8]. Excellent agreement was found between our theoretical calculations of mobility in boron-doped. silicon and the data of Thurber et al [12] at 300 K. We