LOW-TEMPERATURE EPITAXIAL-GROWTH AND PHOTOLUMINESCENCE CHARACTERIZATION OF GAN

Epitaxial layers of GaN on sapphire substrates have been grown by meta lorganic chemical-vapor deposition at a deposition temperature as low as 400 degrees C, which is the lowest temperature for successful epita xial growth of GaN by any technique. This is achieved by controlling t he low flow rate of the source gases and by first depositing an AIN bu ffer layer at 400 degrees C. Low-temperature photoluminescence measure ments have been employed to study the optical properties of the films deposited at different temperatures. (C) 1994 American Institute of Ph ysics.