Fe-doping in hydride vapor-phase epitaxy for semi-insulating gallium nitride

Fe-doping of GaN layers of 3 in. in diameter and a thickness of 1 mm in a vertical AIX-HVPE reactor is studied. Ferrocen was used as Fe source. It is shown that a sufficient uniformity of growth conditions, a high purity of undoped GaN layers, and a moderate Fe incorporation of 2×1018 cm−3 allow for growth of semi-insulating GaN layers with a sufficiently high specific resistivity even at elevated temperature. This makes the material suitable as substrate for electronic power devices at high power or in harsh ambient.