Title: Effects of post-annealing on GaN thin films growth using RF magnetron sputtering

Authors: N.A. Othman; N. Nayan; M.K. Mustafa; A.S. Bakri; Z. Azman; N.A. Raship; M.M.I.M. Hasnan; M.H. Mamat; M.Z.M. Yusop; A.S.A. Bakar; M.Y. Ahmad

Addresses: Microelectronics and Nanotechnology-Shamsuddin Research Centre (MiNT-SRC), Institute for Integrated Engineering, Universiti Tun Hussein Onn Malaysia (UTHM), 86400 Parit Raja, Johor, Malaysia ' Microelectronics and Nanotechnology-Shamsuddin Research Centre (MiNT-SRC), Institute for Integrated Engineering, Universiti Tun Hussein Onn Malaysia (UTHM), 86400 Parit Raja, Johor, Malaysia ' Microelectronics and Nanotechnology-Shamsuddin Research Centre (MiNT-SRC), Institute for Integrated Engineering, Universiti Tun Hussein Onn Malaysia (UTHM), 86400 Parit Raja, Johor, Malaysia ' Microelectronics and Nanotechnology-Shamsuddin Research Centre (MiNT-SRC), Institute for Integrated Engineering, Universiti Tun Hussein Onn Malaysia (UTHM), 86400 Parit Raja, Johor, Malaysia ' Microelectronics and Nanotechnology-Shamsuddin Research Centre (MiNT-SRC), Institute for Integrated Engineering, Universiti Tun Hussein Onn Malaysia (UTHM), 86400 Parit Raja, Johor, Malaysia ' Microelectronics and Nanotechnology-Shamsuddin Research Centre (MiNT-SRC), Institute for Integrated Engineering, Universiti Tun Hussein Onn Malaysia (UTHM), 86400 Parit Raja, Johor, Malaysia ' Microelectronics and Nanotechnology-Shamsuddin Research Centre (MiNT-SRC), Institute for Integrated Engineering, Universiti Tun Hussein Onn Malaysia (UTHM), 86400 Parit Raja, Johor, Malaysia ' NANO-ElecTronic Centre (NET), School of Electrical Engineering, College of Engineering, Universiti Teknologi Mara (UiTM), 40450 Shah Alam, Selangor, Malaysia ' Advanced Membrane Technology Research Centre (AMTEC), Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor Bahru, Malaysia ' Low Dimensional Materials Research Center, Department of Physics, Faculty of Science, University of Malaya, 50630 Kuala Lumpur, Malaysia ' Nanorian Technologies Sdn Bhd, 40 & 40-1, Jln Kajang Perdana 3/2, Taman Kajang Perdana, 43000 Kajang, Selangor, Malaysia

Abstract: Radio-frequency (RF) magnetron sputtering is one of the methods to deposit thin films that have been widely used in the deposition of GaN thin films to fabricate optoelectronic devices. However, the crystallisation of the GaN films deposited using RF magnetron sputtering at room temperature shows GaN amorphous structure. Therefore, post-annealed method at temperature 950°C in N2 condition using CVD furnace is applied after GaN thin film was deposited on Si (111) with and without AlN buffer layer by RF magnetron sputtering at room temperature. Here we report the discovery and characterisation of the GaN thin films after post-annealing at 950°C in nitrogen ambient with and without AlN as a buffer layer. X-ray diffraction (XRD) is used to identify the crystal phase of GaN thin films. The surface morphology including thickness, surface roughness and grain size is studied by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The analyses of XRD show the amorphous structure for the GaN thin films with and without AlN buffer layer that does not undergo post-annealing. After undergoing post-annealing, it does not show any crystalline structure of GaN but crystalline structure of gallium oxide (Ga2O3) dominantly exists in the GaN thin film without AlN buffer layer. AFM analysis shows the grain size and the surface roughness for GaN thin film without AlN buffer layer increases after annealing which are 50.15 nm and 0.87 nm compared with before annealing which are 43.42 nm and 0.61 nm respectively. However, the grain size and surface roughness for GaN films without buffer layer are lower compared with GaN films with the AlN buffer layer even after post-annealing process which are 98.13 nm and 1.30 nm, respectively.

Keywords: gallium nitride; aluminium nitride; RF-magnteron sputtering; crystal quality; post-annealed; thin films; deposition.

DOI: 10.1504/IJNT.2022.124511

International Journal of Nanotechnology, 2022 Vol.19 No.2/3/4/5, pp.316 - 326

Published online: 27 Jul 2022 *

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