The transconductance of SiC metal–oxide–semiconductor field-effect transistors (MOSFETs) is typically much lower in devices fabricated on the 4H-SiC polytype compared to 6H. It is believed that this behavior is caused by extreme trapping of inversion electrons due to a higher density of traps Dit at the SiC/SiO2 interface in 4H-SiC. Here we present an approach for profiling Dit versus energy in the band gap using a modified capacitance–voltage technique on large-area MOSFETs. We find that Dit increases towards the conduction band edge Ec in both polytypes, and that Dit is much higher in 4H- compared to 6H-SiC for devices fabricated in the same process lot.
Experimental and mathematical consideration of microstructural coarsening during liquid-phase sintering has resulted in kinetic laws which define grain size to the third power as being proportional to the isothermal sintering time. Despite those prior efforts, the situations typical to liquid-phase sintering are poorly treated by the current models because the models assume a structure consisting of widely separated spherical grains (zero contiguity). No experiment had been completed to quantify the effect of contiguityon the growth kinetics. In order to do this, the contiguity and growth rates of tungsten grains in a liquid matrix at 1,750K were measured in sintered heavy alloys of 78,83, 88, 93 and 98 wt. % W balanced with 70Ni-30Fe. The observed grain growth rates were compared with the theoretical predictions of the LSW theory and volume fraction modified theories. By modifying the volume fraction effect with a contiguity term, a model was produced that closely followed the experimental results.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.