The recent development of LEC GaAs crystals has been reviewed, with paying attention on 150 mm large crystals. In order to meet the rapidly increasing demand for larger wafers used for microwave devices, crystals of 150 mm in diameter have been successfully developed and are now being produced industrially. The development of this larger wafer is based on technologies such as multi-zone heater furnace technology, three step annealing and polishing technologies.
