Polytype controlled SiC epitaxy on on-axis 6H-SiC(0001) by adding HCl during growth

The homoepitaxial growth of 6H-SiC is demonstrated on on-axis 6H-SiC(0001) substrates at 1475 degrees C by adding HCl during the growth by chemical va por deposition. In prior studies, a pregrowth stepped surface obtained eith er by several-degree off-cut substrates or a HCl pregrowth etch was require d to suppress 3C-SiC inclusions and to achieve homoepitaxial growth of 6H-S iC. In contrast, the addition of HCl during the growth decorates the grown surface via etching to provide an in situ stepped surface where step-flow g rowth of 6H-SiC occurs. Atomic force microscopy of the deposited films show s the addition of HCl produces a much more regular step and terrace structu re that is characteristic of near equilibrium, step-flow growth. In additio n, HCl can reduce the surface supersaturation and growth rate, remove the u ndesired nucleation sites for 3C-SiC, and etch 3C-SiC inclusions over 6H-Si C, all of which benefit the homoepitaxial growth of 6H-SiC on on-axis subst rates. (C) 2000 The Electrochemical Society. S1099-0062(00)03-109-6. All ri ghts reserved.