Present status and challenge of metal organic vapor phase epitaxy equipment for the epitaxial growth of GaN power electronic devices on silicon substrate

Abstract

Impact of growth rate on the productivity of GaN on Si is described as well as the requirements for the epitaxial growth equipment of Metal Organic Vapor Phase Epitaxy (MOVPE). In order to compensate the large thermal mismatch between GaN and silicon substrate multi-layer buffer structure composed of high aluminum containing AlGaN and GaN is used. Because a parasitic reaction between trimethyl-aluminum and ammonia takes place to bring particulates, it is difficult to employ high growth rate for AlGaN. However, total process time should be less than 4 hours for the growth of 5 μm thick layers in order to make the total epitaxial cost less than an expected commercial price. Therefore, we must optimize the buffer layer structure so that the buffer layer works well as a strain compensating layers as well as the growth time is within an acceptable time limit.