20110024880 | NANO-PATTERNED SUBSTRATE AND EPITAXIAL STRUCTURE - A nano-patterned substrate includes a plurality of nano-particles or nanopillars on an upper surface thereof. A ratio of height to diameter of each of the nano-particles or each of the nanopillars is either greater than or equal to 1. Particularly, a ratio of height to diameter of the nanopillars is greater than or equal to 5. Each of the nano-particles or each of the nanopillars has an arc-shaped top surface. When an epitaxial growth process is applied onto the nano-patterned substrate to form an epitaxial layer, the epitaxial layer has very low defect density. Thus, a production yield of fabricating the subsequent device can be improved. | 02-03-2011 |