Analysis of trap state densities at HfO2/In0.53 Ga0.47 As interfaces

Abstract

HfO2 was deposited on n - and p -type In0.53 Ga 0.47 As by chemical beam deposition. Interface trap densities (D it) and their energy level distribution were quantified using the conductance method in a wide temperature range (77 to 300 K). A trap level close to the intrinsic energy level caused the Dit to rise above 1013 cm-2 eV-1. The trap level at midgap gives rise to false inversion behavior in the capacitance-voltage curves for n -type channels at room temperature. The apparent decrease of the Dit close to the band edges is discussed. © 2010 American Institute of Physics.