Ion implantation damage in GaAs measured by the channelling of85Kr

Radiation damage due to implantation of 84Kr in GaAs has been investigated using the dechannelling of 85Kr injected into the <110> channelling direction in the crystal. The radioactive 85Kr range profile, in particular its departure from that expected for ions penetrating a damage free lattice, is used as a monitor of lattice disorder. Using this technique both fluence, flux and target temperature effects have been investigated. The level of damage following 40 keV Kr room-temperature implantations was found to increase with flux employed in the irradiation and consequently influences the distribution of implanted ions. A temperature of 120°C during implantation of medium dose 40 keV Kr was sufficient to repress most of the implantation damage.