Agglomeration enhancement of AlN surface diffusion fluxes on a (0001)-sapphire substrate grown by pulsed atomic-layer epitaxy techniques via MOCVD
Document Type
Article
Publication Date
5-1-2020
Abstract
An atomically flat covering with a dense and crack-free surface of aluminium nitride films was successfully deposited on a sapphire-(0 0 0 1) substrate through a pulsed atomic-layer epitaxy technique via horizontal metalorganic chemical vapour deposition. The distribution of surface diffusion energy for the as-deposited pulsed atomic-layer epitaxy aluminium nitride films was examined by integrating the growth temperature at 1120 degrees C, 1150 degrees C and 1180 degrees C, respectively. The micrograph from field emission scanning electron microscopy and atomic force microscopy topography analyses disclosed a dense and crack-free surface with near atomically flat aluminium nitride films was obtained at 1180 degrees C with the smallest root mean square surface roughness of 0.98 nm. The progression of the E-2 (high) peak frequency retrieved from the Raman spectra was analysed to understand the in-plane compressive strain generated within the as-deposited aluminium nitride films. The lowest screw and mixed-edge threading dislocation densities were calculated to be 2.06 x 10(7) and 7.33 x 10(9) cm(-2), respectively, implying an enhancement in the kinetic mobility of the AlN surface diffusion fluxes when deposited at 1180 degrees C. The photoluminescence and X-ray photoemission scan spectra also presented a low inclusion of foreign impurities on the surface of the aluminium nitride film.
Keywords
C-Plane Sapphire, High-Quality Aln, Aluminum Nitride, Structural-Properties, Gan Films, Temperature, Deposition, Defect, Luminescence, Templates
Divisions
PHYSICS
Funders
OSRAM Opto Semiconductor SDN BHD,Ministry of Higher Education (MOHE) Long Term Research Grant Scheme (LRGS) LR001A-2016A PV015-2015
Publication Title
CrystEngComm
Volume
22
Issue
19
Publisher
Royal Society of Chemistry
Publisher Location
THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND