Effect of C/Si ratio on the characteristics of 3C-SiC films deposited on Si(100) base on the four-step non-cooling process

The growth of 3C-SiC films on Si(100) substrates by low pressure hot-wall chemical vapor deposition is described. The investigation reveals that the C/Si ratio plays an important role in crystalline quality and surface morphology of 3C-SiC films. Comparisons of crystalline quality of 3C-SiC films with different C/Si ratio, indicate that the optimum C/Si ratio for high crystalline quality is 4.5. Noticeably, the polycrystalline grains of 3C-SiC films exhibit epitaxial nature with irregular shape and randomly distribution or pyramid-like shape and regular distribution along the 〈110〉 directions, which are dependent on the C/Si ratio. The changes in crystalline quality with increasing C/Si ratio are attributed to the competition of the formation of defects by excess carbon species and the etching of the atomic hydrogen. Meanwhile, the changes of surface morphology are due to the changes of secondary nucleation rate.