Rapid thermal annealing has been used to electrically activate Si‐implanted InP:Fe. A two‐step annealing cycle in which the short (5 s) high‐temperature step is followed by a relatively long (25–60 s) 100 °C lower temperature step gave higher activation and carrier mobility than the corresponding short high‐temperature or long low‐temperature single step annealing cycle. A good surface morphology was achieved by using InP proximity anneal if the maximum annealing temperature is limited to 900 °C for not more than 5 s. The maximum mobilities and activations obtained for 200 keV/5×1013cm−2and 150 keV/1×1013cm−2Si+implants were 1740 and 2260 cm2/V s and 88 and 98%, respectively. The position of the peak carrier concentration in the depth profile closely matched that of the Lindhard–Scharff–Schiott prediction.