Abstract
High-density micro-circle patterned Si substrates were successfully fabricated for the direct overgrowth of thick AlN templates by using NH3 pulsed-flow multilayer AlN growth and epitaxial lateral overgrowth techniques. The experimental results show that an 8-mu m-thick AlN template was grown at a very high growth rate on the substrates. The AlN template had full widths at half maximum of 0.23 degrees and 0.37 degrees for the (002) and (102) reflection planes in X-ray diffraction rocking curves. Atomic force microscopy and transmission electron microscopy confirmed that the roughness of the surface was low (3.5 nm) and the dislocation density was very low (1.5 x 10(8) cm(-2) (screw), 3.7 x 10(8) (edge) cm(-2)).