Sivakumar et al. Nanoscale Research Letters 2011, 6:78 http://www.nanoscalereslett.com/content/6/1/78 Authors’ contributions SM carried out laser processing of the samples, characterisation and drafted the manuscript. KV conceived of the study, and participated in its design and co ordination. BT conceived of the study, and participated in its design and co ordination. All authors read and approved the final manuscript. Competing interests The authors declare that they have no competing interests. Received: 1 September 2010 Accepted: 12 January 2011 Published: 12 January 2011 References 1. Cheng YT, Lin LW, Najafi K: Localized silicon fusion and eutectic bonding for MEMS fabrication and packaging. J Microelectromech Syst 2000, 9:3-8. 2. Lesuffleur A, Im H, Lindquist NC, Oh SH: Periodic nanohole arrays with shape-enhanced plasmon resonance as real-time biosensors. Appl Phys Lett 2007, 90:243110. 3. Mahmood AS, Sivakumar M, Venkatakrishnan K, Tan B: Enhancement in optical absorption of silicon fibrous nanostructure produced using femtosecond laser ablation. Appl Phys Lett 2009, 95:034107. 4. Bettotti P, Cazzanelli M, Dal Negro L, Danese B, Gaburro Z, Oton CJ, Prakash GV, Pavesi L: Silicon nanostructures for photonics. J Phys Condens Matter 2002, 14:8253-8281. 5. Wan Q, Wang TH, Lin CL: Self-assembled Au-Si alloy nanocones: synthesis and electron field emission characteristics. Appl Surf Sci 2004, 221:38-42. 6. Lu W, Lieber CM: Semiconductor nanowires. J Phys 2006, 39:R387-R406. 7. Hwang TY, Vorobyev AY, Guo CL: Ultrafast dynamics of femtosecond laser-induced nanostructure formation on metals. Appl Phys Lett 2009, 95:123111. 8. Tan B, Venkatakrishnan K: Synthesis of fibrous nanoparticle aggregates by femtosecond laser ablation in air. Opt Express 2009, 17:1064-1069. 9. Vorobyev AY, Guo C: Enhanced absorptance of gold following multipulse femtosecond laser ablation. Phys Rev B 2005, 72:195422. 10. Vorobyev AY, Guo CL: Femtosecond laser nanostructuring of metals. Opt Express 2006, 14:2164-2169. 11. Kuznetsov AI, Koch J, Chichkov BN: Nanostructuring of thin gold films by femtosecond lasers. Appl Phys A 2009, 94:221-230. 12. Miyaji G, Miyazaki K: Origin of periodicity in nanostructuring on thin film surfaces ablated with femtosecond laser pulses. Opt Express 2008, 16:16265-16271. 13. Ivanov DS, Rethfeld B, O’Connor GM, Glynn TJ, Volkov AN, Zhigilei LV: The mechanism of nanobump formation in femtosecond pulse laser nanostructuring of thin metal films. Appl Phys A 2008, 92:791-796. 14. Vonallmen M, Lau SS, Maenpaa M, Tsaur BY: Phase-Transformations in Laser-Irradiated Au-Si Thin-Films. Appl Phys Lett 1980, 36:205-207. 15. Zhang Y, Chen JK: Melting and resolidification of gold film irradiated by nano- to femtosecond lasers. Appl Phys A 2007, 88:289-297. 16. Manickam S, Venkatakrishnan K, Tan B, Venkataramanan V: Study of silicon nanofibrous structure formed by femtosecond laser irradiation in air. Opt Express 2009, 17:13869-13874. 17. Sivakumar M, Venkatakrishnan K, Tan B: Study of metallic fibrous nanoparticle aggregate produced using femtosecond laser radiation under ambient conditions. Nanotechnology 2010, 21:225601. 18. Sivakumar M, Venkatakrishnan K, Tan B: Synthesis of Nanoscale Tips Using Femtosecond Laser Radiation under Ambient Condition. Nanoscale Res Lett 2010, 5:438-441. 19. Sarkar DK, Dhara S, Gupta A, Nair KGM, Chaudhury S: Structural instability of the ion beam-mixed Au/Si(111) systems at elevated temperatures. Nuclear Instrum Methods Phys Res B 2000, 168:21-28. 20. Cullity BD, Stock SR: Elements of X-ray diffraction. Upper Saddle River, NJ: Prentice Hall;, 3 2001. 21. Khalfaoui R, Benazzouz C, Guittoum A, Tabet N, Tobbeche S: Irradiation- induced gold silicide formation and stoichiometry effects in ion beam- mixed layer. Vacuum 2006, 81:45-48. 22. Sarkar DK, Bera S, Dhara S, Nair KGM, Narasimhan SV, Chowdhury S: XPS studies on silicide formation in ion beam irradiated Au/Si system. Appl Surf Sci 1997, 120:159-164. 23. Sundaravel B, Sekar K, Kuri G, Satyam PV, Dev BN, Bera S, Narasimhan SV, Chakraborty P, Caccavale F: XPS and SIMS analysis of gold silicide grown Page 5 of 5 on a bromine passivated Si(111) substrate. Appl Surf Sci 1999, 137:103-112. 24. Lu ZH, Sham TK, Norton PR: Interaction of Au on Si(100) Studied by Core Level Binding-Energy Shifts. Solid State Commun 1993, 85:957-959. 25. Ivanov PR, Zhigilei LV: Combined atomistic-continuum modeling of short- pulse laser melting and disintegration of metal films. Phys Rev B 2003, 68:064114. 26. Ni XC, Wang CY, Yang L, Li JP, Chai L, Jia W, Zhang RB, Zhang ZG: Parametric study on femtosecond laser pulse ablation of Au films. Appl Surf Sci 253:1616-1619. 27. Wong YY, Yahaya M, Salleh MM, Majlis BY: Controlled growth of silicon nanowires synthesized via solid-liquid-solid mechanism. Sci Technol Adv Mater 2005, 6:330-334. doi:10.1186/1556-276X-6-78 Cite this article as: Sivakumar et al.: Characterization of MHz pulse repetition rate femtosecond laser-irradiated gold-coated silicon surfaces. Nanoscale Research Letters 2011 6:78. Submit your manuscript to a journal and beneﬁt from: 7 Convenient online submission 7 Rigorous peer review 7 Immediate publication on acceptance 7 Open access: articles freely available online 7 High visibility within the ﬁeld 7 Retaining the copyright to your article Submit your next manuscript at 7 springeropen.com