Combined hydride and metal organic vapor-phase epitaxy of GaN on sapphire Available to Purchase

We describe a method to produce GaN epitaxial layers in a single chamber where a low-temperature buffer layer is deposited using metalorganic vapor-phase epitaxy (MOVPE), followed by conventional hydride vapor-phase epitaxy (HVPE) of GaN at higher temperatures. While a typical $12μm$ sample is investigated here, the GaN film thickness can vary between 2 and $200μm$⁠, with HVPE growth rate ranging from 5 to $60μm∕h$⁠. Cross-sectional transmission-electron microscope images show a dense network of mixed dislocations, whose density is significantly reduced after $6μm$ to the high $107cm−2$ range. 10 K photoluminescence shows bound exciton dominated emission associated with the $A$ and $B$ valence bands and phonon replicas. No yellow emission is observed. This versatile process can be extended to produce additional device layers by MOVPE.