Abstract
By using a scanning infrared polariscope (SIRP), the residual strain was characterized in semi-insulating wafers of slightly Fe-doped InP crystals treated by multiple-step wafer annealing (MWA). The SIRP maps of annealed wafers were compared with those of the as-grown adjacent wafers. It was revealed that the optimized MWA process did not generate an addtional, unwanted residual strain but homogenized its distribution.