VGF crystal growth and vapor-phase Fe doping technologies for semi-insulating 100 mm diameter InP substrates

100 mm diameter ⟨100⟩ semi-insulating InP substrates were obtained after conductive undoped wafers were annealed under volatile FeP₂ atmosphere. Undoped crystals were grown by the VGF method using a high pressure furnace. In this growth method, we investigated the reduction of the temperature fluctuation by computer simulation for preventing twinning. The temperature fluctuation near the seed crystal could be reduced from ±0.3°C to ±0.03°C after improvement of the hot-zone, based on the simulation results. Semi-insulating InP is conventionally produced by Fe doping during crystal growth. In the conventional doping method, the Fe concentration is varied along the growth axis due to Fe segregation in InP. In order to obtain good homogeneity of Fe concentrations from wafer to wafer, we have developed a new Fe doping technology in which wafers are annealed under volatile FeP₂ atmosphere. In this work, we applied this Fe doping technology to 100 mm diameter ⟨100⟩ InP substrates and could obtain large diameter semi-insulating substrates