Structural and photoluminescence analysis of Er implanted LT-GaAs

Characteristic 1.54 /spl mu/m Er/sup 3+/ emission has been observed from Er-implanted and annealed, low-temperature grown GaAs (Be doped and undoped samples). Cross-sectional transmission electron microscopy (TEM) studies reveal very little structural damage for elevated temperature implants up to an Er total fluence of 1.36/spl times/10/sup 14/ Er/cm/sup 2/. No Er emission was observed from any of the as-implanted samples. Post-implantation annealing optimized the Er PL emission intensity near 650/spl deg/C for Be doped samples, while for undoped samples it was near 750/spl deg/C anneal. The beginning of Er precipitation was observed after 750/spl deg/C annealing for the above Er fluence but, on increasing the Er concentration by higher implantation fluences, it was observed after annealing at 650/spl deg/C. These precipitates are likely ErAs.