LOW TEMPERATURE ELECTRICAL PROPERTIES OF SILICON MATERIAL

Abstract

In this paper electrical properties of silicon containing Boron and phosphor (or arsenic) have been measured from 20° to 300°K in the range of carrier concentration 2×1012 to 1×1020 cm-3 at room-temperature. The weak-field transverse magneto-resistance and impurity activation energy methods were used to determine the degree of impurity compensation for some p-type silicon samples and these methods have been compared. Analyses of Hall coefficient and electrical conductivity vs temperature curves indicate the ionization energy of Boron (phosphor) acceptor (donor) levels to be 0.045 eV for low impurity concentration; Fermi degeneracy is found to occur in the range of 1018 to 1019cm-3. Impurity conduction has been observed for carrier concentration 2×1017 to 1×1018 cm-3 for p-type silicon and 5×1017 to 4×1018 cm-3 for n-type silicon respectively. Extrinsic Hall mobility is computed from Hall coefficient and conductivity. The temperature dependence of lattice-scattering mobility is found: μL=2.1×109T-2.7 for holes; μL=1.2×108T-2.0 for electrons.Carrier concentration vs. resistivity and Hall mobility vs. resistivity curves had been plotted for our silicon material in the range of carrier concentration 5×1011 to 1×1020 cm-3. It is aimed to give as reference for preparing silicon material.