7.2 Resistivity
The resistivity vs dopant density relationship for boron-doped silicon at 300 K is shown i.n Figure 7.2. The solid line represents theoretical calculations using equation (4.7). Wagner's [8] resistivity curve and the theoretical line coincide over most of the boron density range. Our theoretical calculations agree with Wagner's resistivity data within 6 percent over the entire range of boron densities considered at T = 300 K. Excellent agreement exists between our experimental data and the theoretical calculations at 300 K. Figure 7.2 also shows excellent agreement between our theoretical calculations and the data of Thurber et al. [12]. Good agreement was obtained with the data of Thurber and Carpenter [75] where total boron density was obtained by the nuclear track technique.
Figure 7.3 shows the resistivity, of gallium- and indium-doped silicon as a function of total dopant density for T = 300 K. As expected, because of the deeper ionization energy of indium as compared to gallium, values of resistivity for gallium doped silicon are lower than values of resistivity for indium-doped silicon at the same total dopant density. Figure 7.3 does not show this at low dopant densities because of the assumed values of background-boron impurity densities. Excellent agreement was obtained between our experimental data and that obtained from Wolfstirn [15] for gallium-doped silicon, and our theoretical calculations at T = 300 K. Data obtained from the two indium-doped samples showed good agreement with the theoretical calculations, but the same was not true'for the data of Schroder et al.[64], and Backenstoss [16]. As seen in Figure 7.3, for each value of measured resistivity, Schroder et al [64] report two different values of measured indium density. The