Characterization of epitaxial layers grown on 4H-SiC (000-1) substrates

SiC is an excellent semiconductor material that can be used in power semiconductor devices. It has the advantages of high thermal conductivity, stable chemical properties, and high critical breakdown field strength. The active region of a SiC device is usually in the SiC epitaxial layer, so the growth of high-quality SiC epitaxial layers is extremely valuable. In this paper, we investigate the epitaxial growth of SiC on n-type 4 degrees off-axis SiC (0 0 0-1) substrates. We used a horizontal hot-wall chemical vapor deposition apparatus for rapid epitaxy on SiC substrates, using C2H4, and SiHCl3 as precursors and H-2 as carrier gas, respectively, and growing at 1350 degrees C,1400 degrees C,1450 degrees C,1500 degrees C, 1550 degrees C, 1600 degrees C for half an hour to get epitaxial layer. The effect of growth temperature on the surface morphology of SiC (0 0 0 -1) epitaxial layer was analyzed and epitaxial layers is characterized by optical microscope, scanning electron microscope, atomic force microscope and Raman scattering instrument, and the growth rate of epitaxial layer was obtained. It is found that the higher growth temperature is helpful to obtain the epitaxial layer with smooth surface and higher content of 4H-SiC under certain pressure, C/Si molar ratio, and following rate of precursor and carrier gas.

Automated summary

SiC is an excellent semiconductor material with high thermal conductivity, stable chemical properties, and high critical breakdown field strength. This paper investigates the epitaxial growth of SiC on n-type SiC substrates and analyzes the effects of growth temperature on the surface morphology of SiC epitaxial layers. The results show that higher growth temperature can lead to smoother surface and higher content of 4H-SiC.