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Highlights: [•] Wet oxidation at 950°C followed by NO anneal at 1175°C reduces the interface trap density to 4–6×1011 cm−2 eV−1. [•] The positive flat band voltage shift caused by low temperature wet oxidation can be suppressed by the following NO anneal. [•] The oxide breakdown fields for Al- and N-implanted C-face 4H-SiC samples are about 1.5 and 5MVcm−1, respectively. [•] The oxide breakdown field of dry oxidation at 950°C is the same as that of wet oxidation at 950°C. [ABSTRACT FROM AUTHOR]

This research proposes a novel 4H-SiC power device structure—different concentration floating superjunction MOSFET (DC-FSJ MOSFET). Through simulation via Synopsys Technology Computer Aided Design (TCAD) software, compared with the structural and static characteristics of the traditional vertical MOSFET, DC-FSJ MOSFET has a higher breakdown voltage (BV) and lower forward specific on-resistance (Ron,sp). The DC-FSJ MOSFET is formed by multiple epitaxial technology to create a floating P-type structure in the epitaxial layer. Then, a current spreading layer (CSL) is added to reduce the Ron,sp. The floating P-type structure depth, epitaxial layer concentration and thickness are optimized in this research. This structure can not only achieve a breakdown voltage over 3300 V, but also reduce Ron,sp. Under the same conditions, the Baliga Figure of Merit (BFOM) of DC-FSJ MOSFET increases by 27% compared with the traditional vertical MOSFET. Ron,sp is 25% less than that of the traditional vertical MOSFET. [ABSTRACT FROM AUTHOR]

Abstract: The goal of this research is to investigate the correlation of reverse characteristics of Schottky barrier diodes (SBDs) and surface morphological defects on 4° (off-axis) carbon (C) face, 4° and 8° silicon (Si) face 4H-SiC. Different dimensions of SBDs with boron-implanted edge terminations are fabricated on 4° C-face, 4° and 8° Si-face 4H-SiC samples. The ideality factor for these three samples is about 1.1. Average breakdown voltages of 4° Si-face 4H-SiC SBDs are higher than the other two samples, particularly for large size SBDs. Breakdown voltages of 1500 and 2000μm 4° Si-face SBDs can reach over 1000V. This value is about two times higher than the other two samples, though the root-mean-square (RMS) roughness of 4° Si-face samples obtained from atomic force microscopy (AFM) is 3.5nm. The yield of 1500 and 2000μm 4° Si-face 4H-SiC SBDs with a breakdown voltage over 1000V is more than 50%, much higher than the other two samples. [Copyright &y& Elsevier]