CONTROL OF ELECTROPHYSICAL PROPERTIES OF 4H-SiC POWER MOSFET CHANNEL
Various technological approaches for channel properties control of silicon carbide power MOSFET have been described and summarized. Among them are gate oxide thermal growth or deposition with subsequent anneal, introduction of group V elements to the 4H-SiC/SiO2 interface, and buried channel formation by epitaxial CVD growth. Characteristics of lateral MOSFETs fabricated on low doped p-type epilayer with Al concentration of 1 · 1016 cm–3 and high doped Al-implanted p-well with Al concentration of 1 · 1018 cm–3 have been compared. To increase the channel mobility and dielectric breakdown field, as well as to reduce transistor threshold voltage we recommend the following approaches: formation of the p-region of transistor on low-doped epilayer and P/As implantation prior to oxide thermal growth combined with interface states passivation by nitrogen.
Authors: A. I. Mikhaylov, A. V. Afanasyev, V. A. Ilyin, V. V. Luchinin,S. A. Reshanov, A. Schöner
Keywords: Power electronics, silicon carbide, MOSFET, interface, gate oxide, channel, mobility
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