Electrical and physical characterization of gate oxides on 4H-SiC grown in diluted N2O

Abstract

A systematic electrical and physical characterization of gate oxides on 4H-SiC, grown in diluted N2O at 1300 °C, has been performed. Electrical characterization by the high-frequency C-V technique, conductance technique, and slow trap profiling method reveals that the densities of interface and near-interface traps, and the effective oxide charge for gate oxides grown in 10% N2O are the lowest, compared to gate oxides grown in 100% and 0.5% N2O. These results are supported by physical characterizations using x-ray photoelectron spectroscopy, secondary ion mass spectroscopy, and atomic force microscopy. It has been shown that carbon clusters, accumulated at the SiC-SiO2 interface, directly influence the roughness of the interface and the densities of the interface and near-interface traps.

Comparison of metal-organic decomposed (MOD) cerium oxide (CeO2) gate deposited on GaN and SiC substrates

“…2e). It has been reported that the decomposition of SiC happened during thermal nitridation and oxidation in SiO 2 /SiC system [10,19]. The decomposition of SiC was enhanced when the annealing temperature increased.…”

Physical characterization of post-deposition annealed metal-organic decomposed cerium oxide film spin-coated on 4H-silicon carbide

“…Intensive studies have been carried out on SiC MOS-based devices and it is crucial to have a high quality gate oxide deposited or grown between a metal electrode and a SiC substrate. NitridedSiO 2 has been widely employed as gate oxide in SiC MOS-based high power devices, owing to its low interface and slow trap densities, high reliability, and low leakage current [7][8][9][10][11][12][13][14][15][16][17][18][19]. Nevertheless, the maximum permissible electric field in SiC-based devices is restricted by the nitrided-SiO 2 due to its low dielectric constant (k = 3.9) compared to SiC (k = 9.7), as scaled by the Gauss's law at the interface [20].…”

Analysis of Nitrogen State on MOS Interface of 4H-SiC m-Face after Nitric Oxide Post Oxidation Annealing (NO-POA)

“…Because the 397.8 eV spectrum indicates that N forms three chemical bonds with Si, it is assumed that most of the N at the SiO 2 /SiC interface replaced C. Furthermore, since all the N 1s HAXPES spectra sweep toward the higher energy side, the N 1s spectra were fitted using a set of three Gaussian representations [19]. Samples at all the NO annealing temperature showed a Si 2 -N-O bonding signal strength of around 10% to 20% of the main Si-N signal value, and the existence of Si 2 -N-O bonding with a similar ratio may be assumed on the interface.…”