Variations of high-pressure thermoelectric and mechanical properties of Si single crystals under doping with N and P-T pre-treatment

A set of Czochralski-grown Si (Cz-Si) single crystals doped with nitrogen N and P-T pre-treated has been characterized using thermoelectric power measurements at room temperature under ultrahigh pressure P (0-20 GPa). A pressure value of the semiconductor-metal phase transition was established and observed to increase under doping with nitrogen. The influences are discussed of both N doping and P-T pre-treatment conditions on the properties of Cz-Si. A correlation has been established between the transition pressure and the concentration of residual interstitial oxygen Oi always present in Cz-Si. The contraction of samples' thickness under pressure was compared with the data of microindentation. Both mechanical properties exhibited anomalies near the direct structural phase transition into the body-centred tetragonal lattice (β-Sn).