Molecular-beam-epitaxy (MBE) and atomic-layer-deposition (ALD) high-j HfO2 dielectrics have been insitu deposited on MBE-grown pristine p-and n-In0.53Ga0.47As(001). The HfO2/In0.53Ga0.47 As metal-oxide-semiconductor capacitors (MOSCAPs) from both methods all exhibit excellent capacitance-voltage (C-V) characteristics with true inversion and low leakage current densities. Moreover, interfacial trap densities (D-it's) with no discernible peaks at the mid-gap were measured using the temperature-dependent conductance method. Both HfO2/InGaAs hetero-structures have exhibited outstanding thermal stabilities to 800 degrees C. (C) 2017 Elsevier B.V. All rights reserved.