GaN pn-structures grown by hydride vapor phase epitaxy

For the first time, GaN pn-junctions were fabricated by hydride vapor phase epitaxy. GaN pn-structures were grown directly on 6H-SiC substrates without any buffer layer. Undoped GaN layers were n-type with N-d-N-a concentration ranged from 1x10(17) to 5x10(18) cm(-3) Magnesium was used as an acceptor to grow p-type GaN layers. Mg atomic concentration determined by secondary ion mass spectroscopy ranged from 5x10(19) to 5x10(20) cm(-3) As-grown GaN layers doped with Mg were p-type, and p-type conductivity was improved by post-growth anneal. Mesa diodes with a vertical current flow geometry were formed by reactive ion etching. The position of the GaN pn-junction was determined by the electron beam induced current method. The electrical characteristics of the pn diodes were studied. Electroluminescence from the pn diodes was measured.