that the sheet resistance thereof is uniform and warp is less in the wafer 1 in addition to the above heating apparatus such a heating apparatus may be used for carrying out the process of the invention in which a semiconductor wafer continuously moves through the radiating area therein along an air cushioned track or a heating apparatus is provided integral with an ion implanting apparatus such that ions are implanted in a semiconductor wafer and thereafter the wafer is annealed in the same chamber further in place of the mirror with the paraboloidal reflecting surface a mirror with an ellipsoidal reflecting surface may be used to focus the light the anneal time by the heating apparatus is about several seconds so that the ion implanted region can be electrically activated without redistribution and a shallower junction can be formed when a semiconductor device such as a gaas compound semiconductor device which is thermally unstable is manufactured its ion implanted region can be activated in a short time period by the light radiation anneal thus in this case the vaporization of ga or as and also the diffusion of cr can be suppressed hence the generation thermal conversion layer is avoided and the.