3C-SiC Heteroepitaxial Growth by Vapor-Liquid-Solid Mechanism on Patterned 4H-SiC Substrate Using Si-Ge Melt

In this work, we report on the use of patterned 4H-SiC(0001) substrates for the heteroepitaxial growth of 3C-SiC by vapor-liquid-solid (VLS) mechanism using Ge(50)Si(50) melt. Mesas structures of various size and shape were obtained by standard photolithography and dry etching processes. On the temperature range investigated 1300-1450 degrees C, 3C-SiC deposit was obtained on top and outside the mesas. Some lateral enlargement of these mesas was observed, but it was systematically homoepitaxial. The lateral growth rate was found rather low compared to other techniques like chemical vapor deposition, with a maximum value of similar to 12 mu m/h. In addition, elimination of twin boundaries (TBs) inside the 3C-SiC deposit on top of the mesas was observed in the temperature range of 1400-1450 degrees C and for specific mesa shape or orientation of the sidewalls. The best case for eliminating these TBs was found to be with initially circular mesas, which spontaneously form well orientated hexagonal facets and then lead to TB-free deposit on top after VLS growth.