Research of Current Mode Atomic Force Microscopy (C-AFM) for Si/SiC Heterostructures on 6H-SiC(0001)

Si/SiC heterostructures with different growth temperatures were prepared on 6H-SiC(0001) by LPCVD. Current mode atomic force microscopy and transmission electron microscopy were employed to investigate the electrical properties and crystalline structure of Si/SiC heterostructures. Face-centered cubic (FCC) on hexagonal close-packing (HCP) epitaxy of the Si(111)/SiC(0001) heterostructure was realized at 900℃. As the growth temperature increases to 1050℃, the <110> preferred orientation of the Si film is observed. The Si films on 6H-SiC(0001) with different growth orientations consist of different distinctive crystalline grains: quasi-spherical grains with a general size of 20 μm, and columnar grains with a typical size of 7 μm×20 μm. The electrical properties are greatly influenced by the grain structures. The Si film with <110> orientation on SiC(0001) consists of columnar grains, which is more suitable for the fabrication of Si/SiC devices due to its low current fluctuation and relatively uniform current distribution.