Dr. Andriy Kovalskiy
Research Highlights

Recent Scientific Achievements

  • Ultrathin (~500 nm) IR Fresnel lenses with focal point < 1mm on chalcogenide glass thin films (see Kovalskiy A., Cech J., Tan C.L., Heffner W.R., Miller E., Waits C.M., Dubey M., Churaman W., Vlcek M., Jain H. Chalcogenide glass thin film resists for grayscale lithography. Proceedings SPIE, vol. 7273, 2009, p. 72734A1-72734A12. Relevance: microoptics. photonics, MEMS, remote sensing, silicon technology
  • Finest structures (~7 nm) on glass photoresists obtained by electron-beam patterning (see: Neilson J., Kovalskiy A., Vlcek M., Jain H., Miller F. Fabrication of nano-gratings in arsenic sulphide films. Journal of Non-Crystalline Solids, vol. 353, 2007, p. 1427-1430). Relevance: Nanolithography
  • Mechanism of Ag photo-diffusion in chalcogenide glass thin films by high resolution XPS, EXAFS and QEXAFS (see: Kovalskiy A., Miller A., Jain H., Mitkova M. In-situ measurements of X-ray-induced silver diffusion into Ge30Se70 thin films. Journal of the American Ceramic Society, vol. 91(3), 2008, p. 760-765. Relevance: MEMS, silicon technology, memory cells
  • Development of novel gray-scale, hard photoresist masks based on Ag photo-diffusion in chalcogenide glass thin films (see: Kovalskiy A., Jain H., Neilson J.R., Vlcek M., Waits C.M., Churaman W., Dubey M. On the mechanism of gray scale patterning of Ag-containing As2S3 thin films. Journal of Physics and Chemistry of Solids, vol. 68, 2007, p. 920-925). Relevance: MEMS, Silicon Technology
  • Mechanisms of radiation-induced effects in ternary systems of chalcogenide glassy semiconductors in dependence on chemical composition, phase transitions, free-volume parameters, covalent bonds concentration, features of coordination defect formation processes (see: Kovalskiy A. Compositional trends of radiation induced effects in ternary systems of chalcogenide glasses. Radiation Effects & Defects in Solids, vol. 158, 2003, p. 391-397). Relevance: Sensors of High-Energy Ionizing Radiation, Optical Materials
  • Development of multicomponent ceramic compositions with optimized exploitation parameters for manufacturing of NTC thermistors (see: Patent of Ukraine No 47534 UA, H01C7/04, H01C7/13, C04B35/00//C04B101:00; application No 2000041956 from 06.04.2000). Relevance: NTC Thermistors
  • Electronic structure of chalcogenide vitreous semiconductors by high-resolution XPS (see: Kovalskiy A., Jain H., Miller A., Golovchak R., Shpotyuk O. A study of reversible γ-induced structural transformations in vitreous Ge23.5Sb11.8S64.7 by high resolution X-ray photoelectron spectroscopy. Journal of Physical Chemistry B, vol. 110, 2006, p. 22930-22934). Relevance: Fundamental Glass Science, Optical Materials