Depth-Resolved Cathodoluminescence Study of Annealed Silicon Implanted Gallium Arsenide

摘要

Depth-resolved cathodoluminescence was performed on Si ion implanted GaAs. The samples were Cr doped semi-insulating GaAs crystals grown using the horizontal Bridgman method. Nine samples were prepared for this study, four were implanted with 100 keV Si ions at a fluence of 10 to the 13th power/sq. cm, and five were left unimplanted. One each of the implanted and unimplanted samples were annealed at 800 C for 10 minutes, 800 C for 10 seconds, 900 C for 10 minutes, or 900 C for 10 seconds, for a total of eight samples. The ninth sample was left unannealed and unimplanted as a control. Cathodoluminescence data was taken using 1000 V electrons as an excitation source. Depth resolution was achieved by taking spectral data and successively chemically etching the surface of the crystal in 250 A steps. No new peaks were observed in the GaAs during the experiment. The 800 C/10 minute anneal proved to have the greatest effect in optically activating the impurities in the unimplanted samples. The 900 C/10 minute anneals exhibited spectra associated with vacancy complexes.