Recent progress of Na-flux method for GaN crystal growth

Abstract

Abstract In this review, the history of research and development of the Na-flux method for growing single GaN crystals is summarized from its discovery in 1994 until the present. Underlying the development of the Na-flux method, which has become one of the more important technologies for growing high quality GaN crystals, there have been several important innovations without which it would have been impossible to achieve current technical levels. Here, we describe the development of the Na-flux method through these innovations, including a method for controlling nucleation by adding carbon, single- and multipoint seed techniques, and a hybrid of the flux-film coated and multipoint seed approaches.