Thermal treatment of semiconductor samples in the range ∼ 650 to 900°C is an integral part of planar device processing for the activation of implanted ion species. This letter describes a rapid annealing procedure for the short-term treatment of such implants, which from data obtained on InP is seen to result in high activation efficiencies and mobilities ∼ 85 percent and 2600 cm2/V.s, respectively, while at the same time minimizing surface degradation and bulk impurity redistribution.