Electrical Behavior of Ge and (Ge+As) Implanted Gallium Arsenide.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
Pagination or Media Count:
The amphoteric electrical properties of single implants of Ge and dual implants of Ge and As into semi-insulating Cr-doped GaAs have been studied using the Hall-effectsheet-resistivity measurement method. Room temperature implantation was performed at an ion energy of 120 keV with a dose ranging from 5 x 10 to the 12th power to 3 x 10 to the 15th power per sq cm. The implanted samples were annealed at 900 C for 15 minutes. The results of carrier profile measurments show the amphoteric behavior of Ge, and the Ga-site occupancy by the Ge ions are signficantly enhanced by the addition of As ions. In general, the carrier depth profiles show relatively flat but considerably fluctuating distributions. Capacitance-voltage C-V measurements were also made on some samples with low enough carrier concentrations, and the Hall profiles corrected for surface depletion widths were compared with the C-V profiles. SIMS atomic distributions of Ge have also been measured, the the results show that the Ge atomic profiles of the as-implanted samples do not follow the LSS Guassian distribution. The SIMS profile for annealed samples show very little redistribution of the Ge ions. A comparison of the Hall and SIMS data shows that carrier concentrations are much less than the number of Ge ions in most of the implanted region. This is probably due to the unannealed implantation damage andor electrical self-compensation. Author
- Solid State Physics