Pulsed electron beam annealing has been used to activate high‐dose silicon implants in InP. Peak concentrations ≳ 1019cm−3are obtained without any appreciable carrier freezeout on cooling to 78 °K. Such activation is comparable to that obtained on thermal annealing and is seen on samples implanted at both room temperature (amorphous) and 200 °C. In common with the behavior reported for GaAs, the mobility is similarly curtailed below thermally annealing values. Though the initial polished appearance is generally retained, unusual thermal oxidation and anodization properties suggest the possibility of surface phosphorous loss.