Interfacial energy barrier height of Al2O3/H-terminated (111) diamond heterointerface investigated by X-ray photoelectron spectroscopy

The interfacial band configuration of the high-kappa dielectric Al2O3 deposited at 120 degrees C by atomic layer deposition (ALD) on boron- and phosphorus-doped hydrogen-terminated (111) diamond was investigated. Performing X-ray photoelectron spectroscopy measurements of core level binding energies and valence band maxima values, the valence band offsets of both heterojunctions are found to be Delta E-V = 1.8 eV and Delta E-V = 2.7 eV for Al2O3/H(111)p and Al2O3/H(111)n, respectively. The ALD Al2O3 bandgap energy was measured from the O 1s photoelectron energy loss spectra to be E-G(Al2O3) = 7: 1 eV. The interfacial band diagram configuration is found to be of type II for both Al2O3/H(111)p and Al2O3/H(111)n heterostructures having conduction band offsets of Delta E-C = 0.2 eV and Delta E-C = 1.1 eV, respectively. The use of doped (111) hydrogen-terminated diamond for developing future diamond metal-oxide-semiconductor field-effect transistors is discussed. Published by AIP Publishing.