Growth of A IN on patterned sapphire substrates was studied. Deep grooves were made on sapphire substrates by a laser-induced backside wet etching technique. KrF excimer laser was irradiated at an interface between sapphire and phenolphthalein/N-methyl-2-pyrrolidone solution, which acts as a super-heating liquid. An etch rate of sapphire was as high as 6 mum/min for laser power of 1.0 J/cm(2). The AlN layer was grown on the patterned sapphire substrate by chemical vapor reaction process at 1190 degreesC for 1 h. On the inclined sidewall of the etched grooves, AlN grew with its c-axis perpendicular to the sidewall. This produced in-plane surfaces which were inclined around 20degrees to the basal plane of sapphire. A threading dislocation density of in-plane AlN domains was 8 x 10(8) cm(-2). (C) 2004 Elsevier B.V. All rights reserved.