The electrical and optical behaviour of halogen-lamp-annealed InP(Fe) implanted with 30 and 70 keV 29Si+ ions (dose 5*1012 cm-2) has been investigated. The annealing was carried out in the temperature range 800-50 ° for a period of 5-20 s using an InP(Fe) proximity cap. The sheet carrier concentration, mobility and low-temperature (11.5 K) photoluminescence were measured. The results demonstrate that the process of defect removal and reordering in 30-keV-implanted samples is faster than in 70-keV-implanted samples for the same dose. Consequently significantly higher electrical activation of approximately=84% and mobility as high as approximately=3000 cm2 V-1 s-1 have been achieved for shallow implantations (30 keV) which are among the best values reported so far with a proximity cap for the InP system. Therefore, an InP proximity cap can be conveniently used without resorting to the complications of dielectric encapsulation, particularly for shallow implantations, for fabrication of InP-based devices. © 1988 IOP Publishing Ltd.