Structural characteristics of Ni + -implanted AlN thin film Shakil Khan 1 , G Husnain 2 , Ishaq Ahmad 2 , Karim Khan 2,3 , Muhammad Usman 2 and Saira Riaz 3 1 Department of Metallurgy and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences, Islamabad, Pakistan 2 Experimental Physics Laboratories, National Centre for Physics, Quaid-i-Azam University, Islamabad 45320, Pakistan 3 Centre of Excellence in Solid State Physics, University of the Punjab, Quaid-i-Azam Campus, Lahore 54590, Pakistan E-mail: shakphy@gmail.com and husnain78@gmail.com Received 27 May 2014, revised 20 August 2014 Accepted for publication 1 September 2014 Published 23 September 2014 Abstract Metal organic chemical vapor deposited (MOCVD) thin films of aluminum nitride (AlN) were irradiated with 700 keV Ni ions at fluences of 1 × 10 12 , 1 × 10 13 , and 1 × 10 14 ions cm -2 . The stopping and range of ions in matter (SRIM) analysis was performed to investigate the depth distribution of the Ni ions and vacancy production in AlN film. The x-ray diffraction (XRD) patterns of the implanted samples show a shift of the AlN (0 0 2) orientation peak towards higher angles at 1 × 10 12 ions cm -2 , exhibiting the incorporation of nickel ions into the AlN phase. The XRD patterns also demonstrated a reduction in shift of the (0 0 2) orientation peak along with the formation of AlNi 3 phase with the increase of ion fluence. The AFM surface analysis of the ion- irradiated AlN film exhibits a rise of film surface roughness. After ion irradiation, the samples were annealed at 900 °C in a nitrogen environment. Annealing reduces the surface roughness of not only the implanted samples but also the as-grown samples. Keywords: AlN, Ion implantation, surface modification 1. Introduction Aluminum nitride (AlN) is a wide bandgap (6.2 eV) semi- conductor material with a broad range of applications due to its excellent chemical and physical properties such as higher surface acoustics velocity, better thermal conductivity (260 Wm -1 K -1 ), superior level of hardness (2 × 103 kgf mm -2 ), elevated fusion temperature (2400 °C), and large value of dielectric constant (9.14). In addition, the wide bandgap make it an interesting material specifically in the field of optoelec- tronics. Moreover, AlN is a suitable candidate for ultraviolet light-emitting diodes (LEDs) and high-power electronic and optical devices capable of operating at higher temperatures. Ion implantation in semiconductors and optoelectronic materials is frequently being used to obtain desired output from the devices by selective doping. However, a certain amount of knowledge about the primary processes of ion-solid interaction in the particular material and their effects on material quality is required to ensure the reliability and reproducibility of the process. Furthermore, the study of defects production in ion- implanted materials is desirable and is an attractive field of research. To understand the different susceptibility of materials to ion-beam-induced damage is also an area of interest for the scientific community [1–4]. In AlN thin film, ion implantation has so far been studied by using various ions beams such as Cr, Co, Mn [5], Eu [6], Gd [7], etc. However, nickel ion (Ni + ) implantation in AlN film has not been reported so far. Ni + is an important transi- tion metal to generate ferroelectric effects in the host material and has previously been used to produce metallic nano- particles in Al 2 O 3 [8]. Ni-related optical centers have also been created in high-purity diamond by using Ni implanta- tions [9]. In AlN, which is a suitable candidate for optical applications, Ni implantations and their effects on the mate- rials properties can produce interesting applications. In the present study, we have mainly focused on the structural effects produced as a result of Ni ion implantations in AlN thin film. It has been observed that the surface of AlN Surface Topography: Metrology and Properties Surf. Topogr.: Metrol. Prop. 2 (2014) 035007 (8pp) doi:10.1088/2051-672X/2/3/035007 2051-672X/14/035007+08$33.00 © 2014 IOP Publishing Ltd 1