High-energy (3 MeV) Si implantations were performed in InP:Fe at an elevated temperature of 200 °C for fluences 8×1014, 2×1015, and 5×1015 cm“2. For the 8×1014 cm−2 fluence, an activation of 82 %, carrier mobility of 1200 cm2/V-s, a peak carrier concentration of 9×1018 cm−3, and lattice quality comparable to that of virgin crystal were obtained. No amorphization takes place for any of the fluences used. Boron compensation implantations were performed in InP:Sn (n sime 2×1018 cm3) at room temperature in the energy range 1 to 5 MeV and fluence range 1011 to 1015 cm−2. After heat treatment, maximum resistivity of the order of 106 Ω-cm was obtained in B implanted InP.