Fabrication and characterization of m‐plane (1‐100) GaN based metal‐oxide‐semiconductor capacitors

Abstract

M‐plane non‐polar, Gallium Nitride(GaN) based metal‐oxide‐semiconductor (MOS) capacitors were fabricated by depositing 150 nm thick low‐pressure chemical vapor deposition silicon dioxide at 900 °C. No positive shift in the flat band voltage of m‐plane GaN MOS capacitors was observed versus temperature, confirming the absence of pyroelectric effects. In contrast, c‐plane (0001) polar, GaN MOS capacitors, show a positive flat band voltage shift versus temperature and the pyroelectric coefficient of –3×109 q/cm2‐K was measured. A small negative shift in flat band voltage was observed in m‐plane GaN consistent with changes in the bulk potential and corresponding decrease in the occupancy of interface traps. Time dependent dielectric(TDDB) measurements were performed at 200 °C and a mean time to failure (MTTF) of 40 hours was measured at an electric field of 5 MV/cm. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)