Measurements of the Thermal-Emission Rates of Electrons and Holes at the Gold Centers in Silicon Using the Small-Signal-Pulsed Field Effect

Abstract

The small-signal-pulsed field effect in the surface-space-charge region of a metal-oxide-semiconductor field-effect transistor structure is developed to investigate the properties of gold impurity in the surface region of silicon. Thermal-emission rates of electrons and holes and their thermal-activation energies at both the gold-donor and -acceptor states are obtained. At 300°K the low-field thermal-emission rates are ep0t+en1t=680/sec at the gold-acceptor center and ep−1t=1.2×107/sec at the gold-donor center. Thermal-activation energy of these emission rates was observed in the range of 216°–370°K for the acceptor center giving EC-EAu-=0.54 eV and in the range of 130°–235°K for the donor center giving EAu+-EV=0.34 eV. The field dependences of the thermal-emission rate and the spatial distribution of gold concentration in the surface-space-charge region of up to 1-μ wide are observed, indicating a pileup of gold at the interface in phosphorus-diffused n-channel devices.