Proceeding of Asian Physics Symposium 2005 December 7-8, 2005, Bandung, Indonesia 73 Temperature Dependence of Mn incorporation into GaN:Mn Deposited Using PA-MOCVD Budi Mulyanti 1,2) , A. Subagio 1,3) , H. Sutanto 1,3) , F.S. Arsyad 1,4) , P. Arifin 1) , M. Budiman 1) , M. Barmawi 1) 1) Laboratory of Electronic Material Physics, Department of Physics, Institute of Technology Bandung (ITB), Bandung 2) Department of Electrical Engineering Education, IndonesiaUniversity of Education (UPI), Bandung 3) Department of Physics, University of Diponegoro (Undip), Semarang 4) Department of Physics, University of Sriwijaya (Unsri), Palembang, E-mail: b_mulyanti@yahoo.com Abstract Magnetic semiconductor GaN:Mn thin films with varied different growth temperature on c-sapphire substrate have been successfully deposited using plasma-assisted MOCVD (Metal Organic Chemical Vapor Deposition) method. Gases that are used as a source of Ga, N and Mn are trimethylgallium (TMGa), nitrogen (N 2 ) and cyclopentadienyl manganese tricarbonyl (CpMnTc), respectively; and hydrogen (H 2 ) is used as a carrier gas for both TMGa and CpMnTc. Surface morphology and the thickness of the grown thin films were characterized by scanning electron microscopy (SEM). X-ray diffraction (XRD) and energy dispersive of X-ray (EDX) were performed to observe crystalline quality and Mn concentration of GaN:Mn thin films. EDX measurements reveal that Mn incorporation into GaN thin film is low at high temperature ( 680 -700 o C ), while the maximum value for homogenous Mn incorporation is at 650 o C of growth temperature (Ga 1-x Mn x N with the x about 0.064). However at 625 o C of growth temperature, there is no Mn incorporation into GaN epilayer. A ω-2θ XRD scan from 25 o to 65 o shows there is no additional peaks are observed in the sample that is grown at relatively low temperatures (650 o C and 680 o C ) indicating that the thin film is single crystal orientation. Meanwhile secondary phases are observed in sample that is grown at 700 o C of growth temperature. The SEM results show that the higher Mn concentration leads to the better surface morphology. The roughening of the film surface was found to increase with decreasing growth temperatures. Keywords: GaN:Mn, PA-MOCVD, GaN:Mn, SEM, XRD, EDX 1. Introduction The discovery of ferromagnetism in diluted magnetic semiconductors (DMS’s) have attracted an opportunity to study spin-polarized transport phenomena, which make it possible to combine the information processing and data storage in one material 1) . DMS is created by incorporating a magnetic element (impurity) into a non magnetic semiconductor, similar to doping. Recently, ferromagnetic semiconductor of GaN:Mn thin films is of great interest because theoretical considerations 2,3) and experimental studies 4-7) show that GaMnN films are magnetic semiconductors with Curie temperatures higher than room temperature. With this high Curie temperature, GaMnN film becomes of promising materials for spintronics devices, in which spin polarization provides additional functionality 8) . One of the devices in question is a light emitting diode (LED) with the polarization of emitted light determined by the spin polarization in the GaMnN layer, a so-called spin-LED. To build such a spin- LED one has to incorporate a high enough density of Mn into the GaN matrix to obtain the high Curie temperature and to fit the GaMnN layer into the LED structure Standard GaN-based LEDs are commonly prepared by metallorganic chemical vapor deposition technique (MOCVD) on sapphire substrates and consist of n-GaN bottom layer, the active multiquantum-well GaN/InGaN region and the top p- GaN layer 9) . In spite of the potential applications, low solubility of magnetic element (Mn) in the compounds such as GaAs and GaN makes it difficult to fabricate ferromagnetic III–V semiconductors and is known to be a major obstacle to overcome for the practical applications 10) . When a high concentration of magnetic element is introduced in excess of the solubility limit, formation of a secondary phase occurs if the conditions are in near equilibrium. Since the