Chloride-based fast homoepitaxial growth of 4H-SiC films in a vertical hot-wall CVD

Chloride-based fast homoepitaxial growth of 4H-SiC epilayers was performed on 4 degrees off-axis 4H-SiC substrates in a home-made vertical hot-wall chemical vapor deposition (CVD) system using H-2-SiH4-C2H4 -HCl. The effect of the SiH4/H-2 ratio and reactor pressure on the growth rate of 4H-SiC epilayers has been studied successively. The growth rate increase in proportion to the SiH4/H-2 ratio and the influence mechanism of chlorine has been investigated. With the reactor pressure increasing from 40 to 100 Torr, the growth rate increased to 52 mu m/h and then decreased to 47 mu m/h, which is due to the joint effect of H 2 and HCl etching as well as the formation of Si clusters at higher reactor pressure. The surface root mean square (RMS) roughness keeps around 1 nm with the growth rate increasing to 49 mu m/h. The scanning electron microscope (SEM), Raman spectroscopy and X-ray diffraction (XRD) demonstrate that 96.7 mu m thick 4H-SiC layers of good uniformity in thickness and doping with high crystal quality can be achieved. These results prove that chloride-based fast epitaxy is an advanced growth technique for 4H-SiC homoepitaxy.