Growth of High-Quality GaN Films on Multi-AlN/Sapphire Templates By MOCVD

Abstract

GaN is an attractive material for the applications in visible and ultraviolet optoelectronics, high power, high temperature and high frequency devices. Sapphire substrates have been widely used for the growth of GaN films. However, it is difficult to grow high quality GaN films because of lattice constant and thermal expansion coefficient between GaN and sapphire substrate. In this paper, we report on the high quality GaN films have been successfully grown on multi-AlN/sapphire templates by metal organic chemical vapor deposition system. The Hall mobility and the carrier concentration of 801 cm2/Vs and 7.9x1016 cm-3 at 300K, respectively, along with low dislocation density of 4.5x107 cm-2 have been achieved. The X-ray rocking curve full-width at half-maximum were 51 and 211 arcsec for (0004) and (20-24) reflection planes also obtained, respectively. Besides that the atomic force microscopy images showed smooth surface morphology and a higher intensity near the band edge was also observed by photoluminescence measurement result.