Growth of GaN Crystals by Na Flux Method

摘要

High-quality and low cost bulk crystals are needed in the field of group III nitride semiconductors in order to develop optical and electrical devices. Research and development of the growth of crystals using large and small seed crystals by the Na flux method has been carried out to grow large-diameter and high-quality bulk GaN crystals. With current technologies, four-inch GaN wafers can be formed from large seed crystals, and dislocation-free bulk shape GaN crystals with a diameter of 2 cm and a height of approximately 1.2 cm can be grown from small seed crystals. To enlarge the diameter of bulk shape GaN crystals, we have developed the coalescence of GaN crystals from many isolated small seeds. In this paper, we report the progress in the development of Na flux growth method for GaN crystals.