Semi-insulating GaN:C epilayers grown by metalorganic vapor phase epitaxy using propane as a carbon source

The influence of propane present in a reactor at various stages of GaN growth by metalorganic vapor phase epitaxy (MOVPE) on sapphire substrates on the character of epitaxial process and the properties of epilayers has been studied. Doped GaN epilayers with carbon concentration 5 $\times$ 10$^{18}$ cm$^{-3}$ characterized by high crystalline perfection, an atomically smooth surface, and electric breakdown voltage above 500 V at a doped layer thickness of 4 $\mu$m have been obtained.