Growth on Differently Oriented Sidewalls of SiC Mesas As a Way of Achieving Well-Aligned SiC Nanowires

Several different growth directions of SiC nanowires (NWs) determined by the substrate surface crystallographic orientation were achieved by conducting vapor liquid solid growth on the top surfaces and the sidewalls of the 4H-SiC mesas. When substrate. dependent (i.e., epitaxial) growth was ensured, six possible crystallographic orientations of 3C-SiC NW axis with respect to the 4H-SiC substrate were realized. They all were at 20 degrees with respect to the substrate c plane, and their projections on the c plane corresponded to one of the six equivalent < 10 (1) over bar0 > crystallographic directions. All six orientations were obtained simultaneously when growing on the (0001) top surface of the 4H-SiC wafer or on the mesa tops. In contrast, no more than two NW orientations coexisted when grown on any particular crystallographic plane of a mesa sidewall. In particular, the {10 (1) over bar0} mesa sidewall plane resulted in only one NW orientation, thereby producing well-aligned NW arrays desirable for device applications.