Growth of 2 inch ZnO bulk single crystal by the hydrothermal method

Zinc oxide (ZnO) single crystals were grown by the hydrothermal method using a platinum inner container. The 2 inch ZnO wafers obtained from these bulk crystals possess an extremely high crystallinity and purity. The electrical resistivity is highly uniform over the entire wafer area. After annealing, the step-and-terrace structure was observed on the surface of the wafer. The etch pit density was decreased to less than 80 cm(-2). These results suggest that these 2 inch ZnO wafers are suitable for wide band gap device applications.