High Temperature Annealing Study of Al2O3 Deposited by ALCVD on n-Type 4H-SiC
Al2O3 has been grown by Atomic Layer Chemical Vapour Deposition (ALCVD) on ntype 4H-SiC using O3 as an oxidant. After post-deposition, annealing at high temperature (1000°C) in Argon atmosphere for different time periods (1h, 2h, 3h) was performed. Bulk and interface properties of the as-grown as well as the annealed films were studied by electrical measurements (CV, IV, DLTS) and Secondary Ion Mass Spectrometry (SIMS) measurements. The electrical measurements show a decreasing shift of the flatband voltage indicating a diminution of the negative oxide charges with increasing annealing time. After annealing at 1000°C for 3h, the flatband voltage shift has decreased to 6V. The SIMS measurements indicate a double interface with a SiOx (x ≤ 2) interlayer in the as-grown samples while only one interface is observed after annealing, leading to improved electrical behavior of the Metal-Oxide-Semiconductor devices.
Robert P. Devaty, David J. Larkin and Stephen E. Saddow
M. Avice et al., "High Temperature Annealing Study of Al2O3 Deposited by ALCVD on n-Type 4H-SiC", Materials Science Forum, Vols. 527-529, pp. 1067-1070, 2006