Nanostructuring silicon-on-insulator thin films with an excimer laser

Laser annealing and ablation was a subject of research since the first days of lasers. Recent interest to this topic is associated with discovering of new thermo-physical regimes at which materials subjected to laser irradiation are being structured at the sub-wavelength dimension scale. Our recent studies report super-resolution in laser ablation of thin films and formation of nano-sharp conical structures on silicon-on-insulator (SOI) initiated by single pulse of a KrF excimer laser operating at the wavelength of 248nm. Application of nano-cones is envisioned in field-emission devices, ultra-dense flip-chip interconnects in microelectronics, electronic interfaces to biological tissues and other areas. Practical importance of this work is partly due to the wide use of SOI in modern microelectronics. While many phenomena may contribute to the lateral mass transfer forming the nano-sharp cones, we identify the motion of the melted silicon associated with different densities of silicon in solid and liquid phases as the primary physical mechanisms of nano-cones formation. Both analytical and numerical models predict predominantly vertical movement of the melting front and then predominantly lateral movement of the solidification front, which, in turn, pushes the molt towards the center of the annealed area. This talk will summarize our recent experimental as well as theoretical work on nanostructuring silicon-on-insulator thin films with an excimer laser.

The speaker: Ivan Avrutsky graduated from Moscow Institute of Physics and Technology in 1986 with honorary Red Diploma (MSc) in laser physics. He received a PhD degree in Physics and Mathematics with major in Physical and Quantum Electronics from the General Physics Institute of the Russian Academy of Sciences in Moscow, in 1988. From 1989-96 Dr. Avrutsky worked as Research Fellow and then Senior Research Fellow at the General Physics Institute. He received the first place Young Investigator Award in 1990 for the studies of resonant phenomena in double-corrugated waveguide gratings. In 1991-96 Dr. Avrutsky coordinated a multi-institutional project on development of high-power aluminum-free semiconductor lasers. From 1996-97 Dr. Avrutsky was Postdoctoral Fellow at Nortel Institute for Emerging Technologies at University of Toronto. There he developed the concept of binary superimposed gratings for widely tunable lasers. The technology has been licensed to Nortel. Since 1998 Dr. Avrutsky is with Wayne State University in Detroit, Michigan, currently in the rank of Associate Professor with appointments at the Department of Electrical and Computer Engineering and Department of Physics and Astronomy. Dr. Avrutsky leads the Integrated Optics and Nano-Photonics Laboratory doing research in optoelectronics, plasmonic metamaterials, and laser processing of materials.