The in-situ metalorganic chemical vapor deposition of Al2O3 on Ga-face GaN metal-oxide-semiconductor capacitors (MOSCAPs) is reported. Al2O3 is grown using trimethylaluminum and O2 in the same reactor as GaN without breaking the vacuum. The in-situ MOSCAPs are subjected to a series of capacitance-voltage measurements combined with stress and ultraviolet-assisted techniques, and the results are discussed based on the presence of near-interface states with relatively fast and slow electron emission characteristics. The in-situ MOSCAPs with Al2O3 grown at 900 and 1000 °C exhibit very small hystereses and charge trappings as well as average near-interface state densities on the order of 1012 cm−2eV−1.

Articles you may be interested inNitride passivation reduces interfacial traps in atomic-layer-deposited Al2O3/GaAs (001) metal-oxidesemiconductor capacitors using atmospheric metal-organic chemical vapor deposition Appl. Phys. Lett. 105, 033513 (2014); 10.1063/1.4891431 In-situ metalorganic chemical vapor deposition and capacitance-voltage characterizations of Al2O3 on Ga-face GaN metal-oxide-semiconductor capacitors Appl. Phys. Lett. 103, 053509 (2013); 10.1063/1.4817385Bulk and interface trapping in the gate dielectric of GaN based metal-oxide-semiconductor high-electron-mobility transistors Appl.Two-dimensional electron gases in Ga-face and N-face AlGaN/GaN heterostructures grown by plasma-induced molecular beam epitaxy and metalorganic chemical vapor deposition on sapphireIn situ Al 2 O 3 on Ga-face GaN metal-oxide-semiconductor capacitors (MOSCAPs) were grown by metalorganic chemical vapor deposition and measured using capacitance-voltage techniques. The flat band voltage and hysteresis had a linear relationship with Al 2 O 3 thickness, which indicates the presence of fixed charge and trap states that are located at or near the Al 2 O 3 /GaN interface. In addition, slow and fast near-interface states are distinguished according to their different electron emission characteristics. Atom probe tomography was used to characterize the in situ MOSCAPs to provide information on the Al/O stoichiometric ratios, Al 2 O 3 /GaN interface abruptnesses, and C concentrations. The in situ MOSCAPs with Al 2 O 3 deposited at 700 C exhibited an order of magnitude higher fast near-interface states density but a lower slow near-interface states density compared with those with Al 2 O 3 deposited at 900 and 1000 C. Furthermore, the 700 C MOSCAPs exhibited a net negative fixed near-interface charge, whereas the 900 and 1000 C MOSCAPs exhibited net positive fixed near-interface charges. The possible origins of various fixed charge and trap states are discussed in accordance with the experimental data and recently reported first-principals calculations. V C 2013 AIP Publishing LLC. [http://dx.