LOW-TEMPERATURE HIGH-FREQUENCY CAPACITANCE MEASUREMENTS OF DEEP-AND SHALLOW-LEVEL IMPURITY CENTER CONCENTRATIONS

Abstract

A simple method is proposed and demonstrated for the determination of a minute amount of deep‐level impurities in the transition region of p‐n junctions from the high‐frequency capacitance change when the junction temperature is lowered from room temperature to 77°K and the junction bias is switched to zero and back to the large reverse bias to set the charge trapped at these centers to the equilibrium value. Sensitivity of 10¹¹ atoms/cm³ and 10⁵ total atoms in the depletion layer is demonstrated in junction gettered by phosphorus glass. Examples are also given for Ni‐ and Audoped silicon diodes and transistors.