Realization of insulating buffer layers via MOCVD-grown, nitrogen-doped (010) β-Ga2O3

We present metalorganic chemical vapor deposition-grown, nitrogen-doped β-Ga2O3 films as an insulating buffer layer on Fe-doped (010) β-Ga2O3 substrates in lieu of a 49% HF treatment to remove unintentional silicon at the substrate–epitaxial layer growth interface. N-doped layer thickness and NH3/N2 flow were systematically varied to experimentally determine the lowest nitrogen concentration and thickness of the buffer layer needed to fully compensate the interfacial silicon peak. The NH3/N2 flow rate was varied from 200 to 1800 sccm. Results showed fully insulating N-doped layers for samples with NH3/N2 flow rates ≥1200 sccm and a thickness of 50 nm. This study demonstrates the efficacy of in situ, controllably doped nitrogen buffer layers as a mitigation method for unintentional interfacial silicon at the substrate–epitaxial layer growth interface.