High-Pressure Treatment up to 25~GPa of Czochralski Grown Si Samples Containing Different Admixtures and Defects

Abstract

The thermoelectric properties of a set of single crystalline Si wafers with dierent oxygen concentration grown by the Czochralski technique have been studied at ultrahigh pressures up to 25 GPa. The dependence of semiconductormetal transition pressure at Czochralski grown Si on the concentration cO of the interstitial oxygen was found to present a convex curve with the maximum near cO ≈ 9 × 10 17 cm −3 . The high pressure thermoelectric power method seems to be suitable for characterization of impurity-defect structure of Si wafers.For Si1−xGex crystals (1% < x < 3%) the strong changes of both the value and the sign of thermoelectric power have been observed at pressures much less than ones of Si-I → Si-II transition. From nanoindentation data the phase transition Si-I → Si-II, corresponding to semiconductormetal electronic transformation has been detected at the loading up to ≈ 10 mN. These ndings suggest a way for creation of integrated circuits, in which zones with dierent types of conductivity and hence dierent p−n, p−n−p etc. structures may be written by applied stress at nanoscale level, and the control on the value of the above stresses now is possible by the proposed nanoindentation technique.

Semiconductor-metal phase transition in LaBi under high pressure

“…1 was performed up to the pressure P ≈ 22 GPa. Some differ ence in behavior of the thermopower under pressure as compared to the first cycle is observed only at the first stage of compression up to ~6 GPa, which can be explained by the effect of structural defects formed in the sample during the previous compression cycle (see, for example, [12]). Above 6 GPa, curves 1 and 2 in Fig.…”