High-dose V + implantation in ZnO thin film structures A.F. Vyatkin a, * , V.I. Zinenko a , Yu.A. Agaphonov a , A.N. Pustovit a , D.V. Roshchupkin a , F. Reuss b , C. Kirchner b , R. Kling b , A. Waag b,c a Russian Academy of Sciences, Institute of Microelectronics Technology, 142432 Moscow district, Chernogolovka, Institutskaya, 6 IPMT RAS, Russia b University of Ulm, D-89069 Ulm, Germany c University of Braunschweig, D-38023 Braunschweig, Germany Available online 24 June 2005 Abstract In the last two decades, diluted magnetic semiconductors have attracted great attention as promising materials for spintronics applications. [K. Sato, H. Katyama-Yoshida, Jpn. J. Phys., Part 2 39 (2000) L555] theoretically predicted thatZnOdopedwithV,Cr,Fe,Co,andNicanbeferromagnetic.Thishasbeenrecentlyconfirmedexperimentallyfor vanadiumdopedZnOfilmswhichweregrownonsapphiresubstrates,usinglaserdepositiontechnique[H.Saeki,H.N. Tabata, T. Kawai, Solid State Commun. 120 (2001) 439]. In the present work, high-dose vanadium implantation was usedtoproduceZn 1x V x O(x  0.10)thinfilmstructures(250nmthick)thathadbeenepitaxiallygrownonsapphire substrates. Implantation with the dose 2 · 10 16 cm 2 was performed to reach a maximum vanadium concentration of 10 at%. To avoid ZnO film amorphization due to radiation damage accumulation [S.O. Kucheyev, J.S. Williams, C. Jagadish, J. Zou, C. Evans, A.J. Nelson, A.V. Hamza, Phys. Rev. B 67 (2003) 094115], all implants were done at ele- vatedtemperatures300and400 °Candioncurrentdensity10 lA/cm 2 .X-raydiffraction,SIMSandphotoluminescence techniques were exploited to study the implanted samples. No luminescence was observed in the implanted samples after implantation procedures. However, annealing at 800 °C for 30 min gave rise to ZnO crystal structure improve- ment. This implies that healing of implantation induced defects is possible even after heavy-ion bombardment. As a result, the photoluminescence peak at 3.359 eV related to the donorbound exiton was detected. Ó 2005 Elsevier B.V. All rights reserved. PACS: 61.72.Ww; 75.50.Pp Keywords: Ion implantation; Magnetic semiconductors; Optical properties; Radiation damage 0168-583X/$ - see front matter Ó 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.nimb.2005.04.097 * Corresponding author. Tel.: +7 095 962 8038; fax: +7 095 962 8047. E-mail address: Vyatkin@ipmt-hpm.ac.ru (A.F. Vyatkin). Nuclear Instruments and Methods in Physics Research B 237 (2005) 179–182 www.elsevier.com/locate/nimb