Effect of Postdeposition Annealing Temperatures on Electrical Characteristics of Molecular-Beam-Deposited HfO₂ on n-InAs/InGaAs Metal–Oxide–Semiconductor Capacitors

The electrical characteristics of molecular-beam-deposited HfO 2 /n-InAs/InGaAs metal–oxide–semiconductor capacitors with different postdeposition annealing (PDA) temperatures (400–550 °C) are investigated. Results show that the sample with the PDA temperature of 500 °C exhibits the best capacitance–voltage ( C – V ) behavior with small frequency dispersion and small hysteresis. The X-ray photoelectron spectroscopy (XPS) spectra show the reduction of the amount of As-related oxides to below the XPS detection level when the PDA temperature is up to 500 °C. As the PDA temperature was increased to above 500 °C, As and In atoms seem to diffuse significantly into HfO 2 , resulting in the degradation of C – V behavior.