Epitaxial Growth Of Cubic Silicon Carbide On Silicon By Sublimation Method

Silicon carbide is a promising semiconductor with wide band-gap, high saturation electron drift velocity, high breakdown electric field and high thermal conductivity and suitable for high-power, high-temperature and high-frequency electron devices. But the growth of silicon carbide crystals is a much difficult task, furthermore cubic silicon carbide is fairly rare. Up to now, the choices of alternative method for Silicon carbide growth are Sub]imation Growth Method, Chemical Vapor Deposition, Liquid Phase Epitaxy, however the 1 imi tat ion in the size and qua] i ty of the crystals by sub] imation growth method is inherent and the growth rate of Chemical Vapor Deposition and Liquid Phase Epitaxy is low. Therefore, according to Sublimation Growth Method and Chemical Vapor Deposition technology, we attempt to grow epitaxial cubic silicon carbide film on Si by sublimation method.Silicon carbide powder as source powder doesn' t sublime less than 1800 'C and the melting of silicon is only 1420'C, thus, the crucible subassembly is designed in a new way and fabricated on the basis of old silicon carbide crystal equipments. This crucible subassembly is used as a assistant carbon source, additionally, the temperature of silicon carbon powder and silicon substrates can be at needful value when the distance between substrates and source powder is small.Normally, a three-step growth process is utilized. The first step is the sintering of the silicon carbide powder, and the purpose of this step is to eliminate impurity from Silicon carbide powder and to obtain a highsublimation decomposition rate of silicon carbide powder. The second step is the carbonization of silicon surface according to the CVD technology, resulting in a cubic silicon carbide buffer layer on the silicon substrate. The last step is the epitaxial growth of cubic silicon carbide on silicon. The typical sample is characterized by X-ray diffraction (XRD), Transmission electron microscope and Raman scattering spectroscopy technique. The results reveal that the growth method should be studied and explored thoroughly because of its feasibility.According to experiment phenomena and test result, the influence of silicon carbon powder and pivotal experiment parameter on epitaxial growth is analyzed. In conclusion, large average granularity silicon carbide powder should be used as source powder if its pureness is high; high supersaturation growth environment should be utilized; the substrate temperature, source temperature and supersaturation should be suited between them.