Formation of Alternating Epilayers of 4H-SiC and 3C-SiC by Simultaneous Lateral Epitaxy

To generate both two-dimensional electron gas (2DEG) and two-dimensional hole gas (2DHG) at will in SiC polytype heterojunctions, simultaneous lateral epitaxy (SLE) method has been extended to form epilayers of alternating stacks of 4H-and 3C-SiC, which includes the first formation of single-domain 4H-SiC on 3C-SiC. The process starts with a spontaneous generation of mononuclear 3C-SiC on the atomically flat wide terrace on 4H-SiC, which expands parallel to the basal plane to form a single-domain 3C-SiC layer having the coherent interface with the underlying 4H-SiC layer. Step-controlled epitaxy is then applied using the adjacent 4H-SiC steps to grow an alternative 4H-SiC layer on top of the 3C-SiC surface, forming another coherent interface. The crystal structure, the interface structure, and the carrier distribution of this stacked epilayers was analyzed. Finally, it is demonstrated that 2DEG occurs at the coherent interface between the 3C-SiC Si-and 4H-SiC C-faces and 2DHG at the 3C-SiC C-and 4H-SiC Si-faces.