Deep trap measurement on S+-implanted layers in GaAs

GaAs substrates were implanted with sulfur at 100, 200, 300 °C, and at room temperature and annealed at 800 °C with SiO2 or Si3N4 protective layers. The density and activation energy of deep traps in the implanted layers were determined from transient capacitance measurements. It is found that implantation at 200 °C and annealing with a Si3N4 film as a protective layer yields the lowest trap density in the implanted layer.