ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
We report investigations of MOS and MOSFET devices using a gate oxide grown in thepresence of sintered alumina. In contrast to conventionally grown dry or wet oxides these oxidescontain orders of magnitude lower density of near-interface traps at the SiO2/SiC interface. Thereduction of interface traps is correlated with enhanced oxidation rate. The absence of near-interfacetraps makes possible fabrication of Si face 4H-SiC MOSFETs with peak field effect mobility ofabout 150 cm2/Vs. A clear correlation is observed between the field effect mobility in n-channelMOSFETs and the density of interface states near the SiC conduction band edge in n-type MOScapacitors. Stable operation of such normally-off 4H-SiC MOSFET transistors is observed fromroom temperature up to 150°C with positive threshold voltage shift less than 1 V. A small decreasein current with temperature up to 150°C is related to a decrease in the field effect mobility due tophonon scattering. However, the gate oxides contain sodium, which originates from the sinteredalumina, resulting in severe device instabilities during negative gate bias stressing
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.527-529.961.pdf
