Direct Growth and Controlled Coalescence of Thick AlN Template on Micro-circle Patterned Si Substrate

Abstract

High-density micro-circle patterned Si substrates were successfully fabricated for the direct overgrowth of thick AlN templates by using NH 3 pulsed-flow multilayer AlN growth and epitaxial lateral overgrowth techniques. The experimental results show that an 8-Î 1/4m-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° and 0.37° 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') and the dislocation density was very low (1.5×10 8 cm -2 (screw), 3.7×10 8 (edge) cm â '2).