Local structure of Mn implanted in gallium arsenide C.H. Chen a , H. Niu b, * , C.Y. Cheng b , H.H. Hsieh c , Y.C. Yu d , S.C. Wu a a Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan b Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu 30013, Taiwan c Department of Electrical Engineering, Chung Cheng Institute of Technology, 335, Taiwan d Institute of Physics, Academia Sinica, Taipei 11529, Taiwan Available online 16 May 2007 Abstract Mn ions (80 keV) were implanted into p-GaAs substrate at room temperature. Rutherford backscattering spectrometry (RBS) and particle-induced X-ray emission (PIXE) with channeling and X-ray absorption structure (XAS) measurements were applied to analyze the local structural environment of the Mn implanted in the host GaAs lattice before and after annealing. The preliminary results showed that the implanted Mn ions preferred to reside on a substitutional site after annealing. Ó 2007 Elsevier B.V. All rights reserved. PACS: 61.85.+p; 61.80.Jh; 68.55.Jk; 75.50.Pp Keywords: Ferromagnetic semiconductor; Ion implantation; Ion-beam-induced epitaxial crystallization; Laser processing 1. Introduction In the last few years, the magnetic and structural prop- erties of dilute magnetic semiconductors (DMSs) have attracted considerable attention due to their potential spin-based device applications. The magnetic property of such materials is based on the introduction of transition metals (TMs) such as Mn and Cr into appropriate crystals. It has been demonstrated that Ga 1x Mn x As material exhibits ferromagnetism for 0.02 < x < 0.06 with T C s> 150 K after post-growth annealing [1,2]. III–V DMSs can- not be fabricated easily because the solubility of TMs is lower than the concentration required for ferromagnetic activity in III–V semiconductors. Low-temperature molec- ular beam epitaxy (LT-MBE) [1,2] and ion implantation followed by pulse laser melting (PLM) [3–5] are a few suc- cessful methods to fabricate Ga 1x Mn x As DMSs thin films. The kinetic energy of the ion beam is useful for inducing the kinetics of solid phase reactions or making possible reaction paths that are not achieved by thermal processing alone. Amorphous thin films such as Si and Ge can be crys- tallized by energetic ion beam irradiation at a considerably lower temperature as compared to conventional furnace annealing or rapid thermal annealing [6,7]. However, to date, very little data on ion-beam-induced epitaxial crystal- lization (IBIEC) in Mn-implanted GaAs wafer have been reported. In this report, the microstructure of Mn-implanted GaAs wafers before and after IBIEC and PLM treatment was investigated by simultaneous Rutherford backscatter- ing spectrometry (RBS) and particle-induced X-ray emis- sion (PIXE) combined with the channeling technique. In addition, a comparison with the PLM-treated samples was carried out in order to clarify the ion beam irradiation effect. 2. Sample preparation and ion channeling experiment P-type (001) GaAs:Zn wafers were implanted with 80 keV Mn + to 7.5 · 10 15 /cm 2 at room temperature. The 0168-583X/$ - see front matter Ó 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.nimb.2007.04.311 * Corresponding author. Tel.: +886 3 571 5131x35852; fax: +886 3 571 7160. E-mail address: hniu@mx.nthu.edu.tw (H. Niu). www.elsevier.com/locate/nimb Nuclear Instruments and Methods in Physics Research B 261 (2007) 570–573 NIM B Beam Interactions with Materials & Atoms