Emission channeling studies of implanted $^{167m}$Er in InP

We have used conversion electron emission channeling to determine the lattice location of $^{167m}$Er ($t_{1/2}$=2.28 s) in InP after 60 keV room temperature implantation of $^{167}$Tm ($t_{1/2}$=9.25 d) at a dose of 6.8 $\times 10^{12}$ cm$^{-2}$. Following annealing at temperatures above the major recovery step of the implantation damage at 100-150°C, we observe around 75% of Er on substitutional In sites. A smaller fraction of Er (7%) is found on substitutional P sites, the remainder on random sites. Annealing the unprotected InP crystal at temperatures above 250°C in vacuum causes a decrease in the channeling effects.