have obtained excellent-agreement between theoretical values of resistivity and our experimental data for boron-, gallium-, and indium-doped silicon at 300 K; our theoretical calculations also agreed with the resistivity data by Thurber et al [12] for boron-doped silicon, and Wolfstirn [15] for gallium-doped silicon.
As shown in Chapter V, however, this theoretical model does not have the same kind of success in describing the Hall mobility and Hall factor for p-type silicon for low dopant densities, and low temperatures. For dopant densities lower than 5xlO cm , this model predicts a value of Hall factor much greater than has been experimentally determined [5,15,38]. A discrepancy like this for the case of p-type germanium was eliminated as the quality of germanium crystals improved. Thus it has been assumed that low values of Hall mobility for low-doped p-type germanium at T = 300 K were caused by compensation. However, compensation alone may not account for low values of Hall mobility in the case of p-type silicon [38]. Recent studies by Nakagawa and Zukotynski [77-] indicate that the use of the exact model in the development of the Hall factor formulation yields results which agree in general with experimental data for the case of p-type silicon. Experimental data for the case of p-type germanium does not agree with the theoretical results of Nakagawa and Zukotynski [77].
.From this study, we have found that the theoretical expressions
derived in this work are adequate for mobility and resistivity calculations for p-type silicon in the temperature range 100 : T 400 K, and 14 18 - 3
.the dopant density range 10 NA 10 1 cm . The theoretical formulation is also adequate for description of the Hall factor and Hall mobility for dopant densities above 5xlO16 cm-3 and temperatures above