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Pulsed-mode metal–organic chemical vapor deposition (MOCVD) growth of ZnSn(Ga)N2on GaN-on-sapphire templates was investigated with the goal of developing stoichiometric, high-quality, epitaxial ZnSnN2-GaN films for integration with GaN-based device structures. It was determined that pulsed-mode growth, during which the Sn precursor was pulsed, enabled the achievement of higher growth temperatures and the avoidance of the formation of Sn droplets, compared to continuous growth. The crystal quality improved with the insertion of a GaN regrown layer prior to the pulsed-mode growth. The stoichiometric ZnSnGa2N4alloy was achieved with a TMSn pulsing time of 15 s in the 1 min growth loop. The valence band offset (VBO) between ZnSnGa2N4and GaN was determined experimentally via X-ray photoelectron spectroscopy to be 0.96 ± 0.10 eV. This value is in good agreement with the predicted value of 0.9 eV, assuming a linear dependence of the VBO on the alloy composition. The results from this work will provide additional design freedom based on III-N/II-IV-N2heterostructures for electronic and optoelectronic devices.

In this work, metalorganic chemical vapor deposition (MOCVD) of (010) β-Ga2O3with fast growth rates was investigated using trimethylgallium (TMGa) as the gallium (Ga) precursor. Key growth parameters including precursor/carrier gas flow, growth temperature, chamber pressure, and group VI/III molar flow ratio were systematically mapped. Surface morphology and charge transport properties of the homo-epi (010) β-Ga2O3thin films were probed to correlate with the crystalline quality. The growth rate of (010) β-Ga2O3thin film increases as the TMGa flow rate increases, and high-quality epi-film is achievable with a fast growth rate up to ∼3 μm/h. By tuning the n-type dopant silane flow rate, the net charge carrier concentration was tuned from ∼1016to 1019cm–3. Room-temperature mobility as high as 190 cm2/V·s was measured for a sample grown with a growth rate of 2.95 μm/h and an electron concentration of 1.8 × 1016cm–3. Temperature-dependent Hall measurement revealed a peak mobility value of ∼3400 cm2/V·s at 53 K. The extracted low compensation level of NA∼ 1.5 × 1015cm–3indicates the high purity of the MOCVD growth of the (010) β-Ga2O3film using TMGa as the Ga precursor. Quantitative secondary-ion mass spectroscopy characterization revealed a relatively high C concentration of 7 × 1016cm–3, indicating that C does not serve as a compensator or a donor in MOCVD grown β-Ga2O3. The results from this study demonstrate the feasibility to grow high-quality Ga2O3thin films with fast growth rates, critical for developing high power electronic device technology.