Metal organic vapor phase epitaxy growth of (Al)GaN heterostructures on SiC/Si(111) templates synthesized by topochemical method of atoms substitution

We report a novel approach for metal organic vapor phase epitaxy of (Al)GaN heterostructures on Si substrates. An approximately 90-100nm thick SiC buffer layer is synthesized using the reaction between Si substrate and CO gas. High-resolution transmission electron microscopy reveals sharp crystalline interfaces with epitaxial relationship between SiC/Si and AlN/SiC layers. Optimization of SiC morphology and AlN seed layer thickness facilitates the growth of GaN layers free of pits (v-defects). It is also found that Si doping eliminates these defects in the case of growth on SiC templates with non-optimized surface morphology. Thus, synthesis of thin SiC buffer layer is suggested as a solution for the interface problems at the initial stage of III-N on Si epitaxy.