Tensile strain introduced in AlN layer grown by metal-organic vapor-phase epitaxy on (0001) 6H-SiC with (GaN/AlN) buffer

An AlN layer with tensile strain along the a-axis was grown on a (0001) 6H-SiC substrate with a (GaN/AlN) buffer layer by metal-organic vapor-phase epitaxy using an alternating source feeding technique. It was experimentally demonstrated that the strain in the AlN layer was affected by the buffer layer structure. On the other hand, the AlN layer grown directly on a substrate without the buffer layer exhibits compressive strain along the a-axis. Strain control in the AlN layer by adjusting the buffer layer structure is proposed.