Electrical properties of gold-doped silicon

The temperature dependence of the Hall coefficient and specific resistivity was measured for gold-doped n-type and p-type silicon. The carrier concentration derived from the value of the Hall coefficient was quantitatively compared with a calculated dependence. If the ratio of the gold concentration to the concentration of the shallow impurities equals N Au/N = 1, then the charge carrier concentration is influenced very strongly by inhomogeneities of the gold distribution. With doping ratios, N Au/N, between 1.5 and 5 in p-type silicon, it is possible to fit the model to the measured dependence with a degeneracy factor gD = 1/16 of the gold donor level. In the case that N Au/N > 10, another additional shallow acceptor level, with an activation energy of 0.033 eV above the valence band edge, influences the electrical properties of gold-doped silicon. After diffusion processes at a temperature of 1200°C, the concentration of this type of impurity is smaller by about one order of magnitude than the gold solubility.