Defining new frontiers in electronic devices with high κ dielectrics and interfacial engineering

Ga2O3(Gd2O3), a high κ gate dielectric, ultrahigh vacuum (UHV)-deposited on GaAs and InGaAs has unpinned the Fermi level in the high-electron-mobility III-V compound semiconductors for the first time. Systematic heat treatments under various gases and temperatures were studied to achieve low leakage currents of 10− 8-10− 9 A/cm2 and low interfacial density of states (Dit's) in the range of < 1011 cm− 2 eV− 1. By removing moisture from the oxide, thermodynamic stability of the Ga2O3(Gd2O3)/GaAs heterostructures and the interfaces were achieved with high temperature annealing, the oxide remains amorphous and the interface remains intact with atomic smoothness and sharpness. The Fermi-level unpinning in atomic layer deposition (ALD) Al2O3ex-situ deposited on InGaAs was achieved. Recent work of extremely high-quality nano-thick single crystal oxides of gamma-Al2O3 and bixbyite cubic Sc2O3 epitaxially grown on Si (111) is discussed. Interfacial manipulation is essential in giving excellent results presented in the paper. X-ray diffraction, reflectivity, and X-ray photoelectron spectroscopy using synchrotron radiation are critical in probing the interfacial properties.