ZrO₂ on GaN metal oxide semiconductor capacitors via plasma assisted atomic layer deposition

Abstract

ZrO2 has been deposited on GaN by Atomic Layer Deposition. Multiple Metal-Oxide-Semiconductor Capacitors with 4.4 nm, 5.4 nm, and 8.5 nm of ZrO2 oxide were fabricated with Cr electrodes. Capacitance measurements produce capacitance densities as high as 3.8 μF/cm2. Current densities of 0.88 A/cm2 at 1 V for the 4.4 nm oxides and hysteresis values of less than 6 mV were observed for the 5.8 nm oxide, indicating an interfacial Dit not greater than 6.4 × 1010 cm2. Temperature dependent current measurements revealed no signature Poole-Frankel component. Comprehensive assessment of these measurements indicates a low defect density oxide formed on GaN with a low number of interface states.