In situ Y2O3 on p-In0.53Ga0.47As—Attainment of low interfacial trap density and thermal stability at high temperatures

Abstract

By in situ depositing Y2O3 on a pristine p-In0.53Ga0.47As surface under ultra-high vacuum, we have attained a low interfacial trap density (Dit) of (2–5) × 1011 eV−1cm−2 from the mid-gap to the valence band edge. The Dit values were extracted from the conductance contours measured from 300 K to 77 K. The small frequency dispersions of 1.2%/dec (300 K) and 0.28%/dec (77 K) in the accumulation region of the capacitance–voltage (CV) characteristics and very small frequency-dependent flatband voltage shifts of 0.021 V/dec (300 K) and 0.011 V/dec (77 K) indicate low border trap densities and low Dit's; these experimental results have not been achieved in previous reports of oxide/p-In0.53Ga0.47As. The Y2O3/p-In0.53Ga0.47As heterostructure also exhibited a high thermal stability of 800 °C, as observed by the low Dit values, small CV frequency dispersions, and an abrupt interface without inter-diffusion in cross-sectional scanning transmission electron microscopy images. Our work has demonstrated a long-sought remedy for the effective passivation of p-type In0.53Ga0.47As, paving the way to high-performance electronic and optoelectronic In0.53Ga0.47As devices.