Growth of Bulk GaN from Gas Phase

The present status of the GaN bulk growth by vapor growth methods is reviewed and is shortly classified into all methods with bulk growth potential. The hydride vapor phase epitaxy (HVPE) as the most developed and already commercialized method using chlorine as transport agent was frequently reviewed before. However, it does not yield true bulk GaN, suffers from perfection limiting heteroepitaxy, direction depending growth rate, parasitic growth and by‐product formation, the latter both limiting the process duration. Therefore, in this review other methods are considered. Alternative transport agents are pronounced, like iodine, hydrogen, oxygen, water and the pseudo halide CN− ‐ ion, which are not able to reveal potential for bulk growth. These mostly less successful approaches, are sometimes repeated, because not adequately published. Halide vapor phase epitaxy (HVPE) is the only commercialized method to grow bulk GaN. This method is compared with other CVT approaches using alternative transport agents. Selected solution growth methods, with potential for bulk growth are introduced for a more comprehensive view. The SEM image shows V‐pits on a cracked carbon doped pseudo HVPE GaN layer. The topics are substrates, defects and doping for n‐type, p‐type and semi‐isolating material.