SiC liquid-phase epitaxy on patterned substrates

This paper is devoted to silicon carbide liquid phase epitaxy on patterned substrates and a corresponding investigation of growth-rate anisotropy. The growth was carried out by container-free liquid phase epitaxy from a Si melt under isothermal conditions. Layers were grown on 6H-SiC Lely substrates. Circular and square mesa-tables and depressions similar to 20 mu m in height were formed using conventional photolithography and reactive-ion etching. The growth temperature was varied from 1450 to 1600 degrees C and growth rates ranged from 0.05 to 2 mu m min(-1). The anisotropy of lateral growth rate was clearly observed on circular mesa-tables which were hexagonal in shape after the growth. The highest growth rate was measured for the [<11(2)over bar 0>] direction, and the lowest growth rate was found for the [<1(1)over bar 00>] direction. The temperature dependence of the normal growth rate and the lateral growth rate in different crystallographic directions was measured, and the activation energy for growth in the different directions was estimated. The crystal quality of SIC layers grown on patterned substrates was studied by X-ray diffraction, X-ray topography, and photoluminescence.