Influence of sublimation surface on mass transport in AlN crystal growth by physical vapor transport process

Abstract

A series of numerical experiments were performed to investigate the influence of the sublimation surface on mass transport during the aluminum nitride (AlN) growth process. The distribution of Al partial pressure is strongly affected by the cover of the sublimation interface. The morphology of the growth interface can be controlled by the cover of the sublimation interface to achieve the growth of a specific crystal shape. Based on the same temperature field, the influence of sublimation interface cover on the growth rate indicates that temperature and temperature gradient are not the main limiting factors of the growth rate and further verifies that Al partial pressure gradient is the rate-limiting step. Under the growth system and specific growth conditions, a smooth growth interface can be obtained by using [0, 2/6] sublimation interface cover, so as to realize the rapid growth of high quality AlN crystals.