Epitaxial Growth of Zinc Oxide Whiskers by Chemical-Vapor Deposition under Atmospheric Pressure

Abstract
ZnO whiskers were epitaxially grown by a chemical-vapor deposition technique employed at atmospheric pressure. Highly oriented ZnO whiskers grew at a substrate temperature of 550°C on (0001)α-Al2O3 substrates with a growth rate of 3.7 nm/s. X-ray diffractometry revealed that the epitaxial relationship between the whiskers and the substrate was determined as ZnO[1010](0001)//Al2O3[1210](0001) or ZnO[1210](0001)//Al2O3[1010](0001). In addition, the full-width at half maximum value of the (0002) reflection was as low as 0.43°. Images obtained using a scanning electron microscope were analyzed and it was found that the whisker tip likely has a radius of curvature of approximately 20 nm. The typical number density of the whiskers has reached 1.3×105mm-2.