Piezoresistance and Magnetic Susceptibility in Heavily Doped<i>n</i>-Type Silicon

Abstract

Piezoresistance and static magnetic susceptibility are measured on phosphorus doped silicon with the donor concentration ranging from 6.10 18 cm -3 to 1.5·10 20 cm -3 and without compensation. Measurements are done over the temperature range from 1.5°K to 500°K The piezoresistance is in excellent accord with a picture that the donor electrons are in a rigid band with the same mass parameters as the conduction band of pure silicon, while the magnetic susceptibility shows deviation from this picture in two respects: one is the additional Curie type paramagnetism predominant at the lowest temperatures and the other is the large Pauli paramagnetism consistent only with larger and concentration dependent effective mass. A discussion is given of the source of these anomalies.