Role of Contacts in Characterization of Deep Traps in Semi-Insulating GaAs by Thermall Stimulated Current Spectroscopy

摘要

The role of contacts in characterization of traps in semi-insulating (SI) GaAs by thermally stimulated current (TSC) methods has been demonstrated by comparing alloyed In and soldered In contacts. Alloyed In contacts, whch have an ohmic characteristic, assure high sensitivities in both TSC and temperature dependent photocurrent (PC), and both are important for determining the trap concentrations in SI GaAs. On the other hand, soldered In contacts, which act like Schottky barriers, cause a singnificant reduction of both PC and TSC, particularly at low temperatures, and can lead to a misinterpretation of TSC results.