High-mobility 2D electron gas in carbon-face 3C-SiC/4H-SiC heterostructure with single-domain 3C-SiC layer

We epitaxially grew a single-domain 3C layer on a step-controlled C-face 4H-SiC substrate to create a 3C/4H-SiC heterostructure. The effectiveness of using such a substrate to grow a thin highly crystalline single-domain 3C layer was demonstrated. The heterostructure exhibited an electron Hall mobility of 7224 cm2/V s at 32 K, which is more than one order of magnitude higher than the best value reported for this structure. From a comparison with the value of 134 m2/V s for a structure with a multi-domain 3C layer, we attribute the high mobility to single-domain formation. The nearly constant sheet carrier density of ∼1.5 × 1013 cm−2 in the temperature range from 34 to 573 K and the high mobility suggest that conduction occurred in a two-dimensional electron gas. Thus, the high potential of C-face 3C/4H heterostructures for high electron mobility transistor applications is displayed.