Laser processing of thin nanostructured oxide films for transparent and conventional electronics

Acronym: PROLAF

Type: CNMP, Contract No. PN II 11-061/2007

Project Director: Dr. Valentin Teodorescu

     Ultraviolet laser irradiation is an unconventional method of thin films processing, which allows the use of the non-equilibrium thermal processes and photo-thermal processes induced by the UV laser radiation, in order to obtain materials and structures at micro- and nanometric scale with new electric and optical properties.
     This project is focused on the study of structural transformations and physical phenomena taking place during laser processing of thin nanostructured oxide films with applications in conventional electronics and, more recently, in transparent electronics. We will study thin films from several oxides classes: HfO2, SiO2, ZnO, Co3O4, as well as doped and mixed oxides with conductors, semiconductor and dielectric electrical properties, films with magnetic properties, with applications to conventional and transparent electronics.
     The majority of the thin oxide films will be deposited by sol-gel method followed by laser annealing. Nanostructured oxide films with thickness within nanometric scale, controlled stoichiometry, reproducibility and uniformity on extended surfaces can be obtained in this way. Comparative studies will be made on the laser radiation effect on thin films of doped SiO2 obtained through RF and sol-gel methods, in order to determine the specific mechanisms related to the laser densification phenomenon in the sol-gel films.
     The structural analyses represent one of this project's main activities. We will proceed to comparative studies of the structure obtained through laser processing and through thermal classical treatments. The main structural data will be obtained by observing film sections (cross section XTEM) by transmission electron microscopy, AFM microscopy, X-rays diffraction, as well spectroscopic methods will be used. The films will be characterized by optical and electrical measurements for their performances in the domain in transparent electronic.

The specific objectives of the project :

  • Study of the sol-gel nanostructured oxide thin films densification and crystallization process achieved by UV laser processing
  • Elaboration of oxide thin films with a high structural uniformity, with • 5 to 50 nm thickness showing interesting semiconductor and magnetic properties.
  • Determination of the experimental conditions of the nitrogen doping processes of the sol-gel ZnO oxide films by laser irradiation in reactive atmosphere conditions (a way to obtain ZnO films with p-type semiconductor properties)
  • Obtaining new experimental parameters for the laser crystallization of sol-gel oxide films, especially for the case of films deposited on heat sensitive substrate (polymeric substrate).

Project coordinator :

National Institute of Materials Physics (NIMP)
105bis Atomistilor str., Bucharest, Magurele, PO Box MG-7, zip code 077125, Romania
Phone: + 40-21-369 0185
Fax: + 40-21-369 0177

Project Director :

Dr. Dr. Valentin Teodorescu , Senior Researcher I
Phone: + 40-21-369 0170 / int. 108
Fax: + 40-21-369 0177

Partener 1: National Institute R&D for Physics of lasers Plasma and Radiation (INCDFLPR)

Partener 1 Project Director :

Dr. Maria Dinescu

Partner 2: Institute for Chemical Physics "Ilie Murgulescu" of the Romanian Academy (ICF) through the Sol-gel Laboratory conducted by Acad. Dr. Maria Zaharescu

Partener 2 Project Director :

Dr. Alexandra Barau

Partner 4: Apel Laser SRL

Partener 3 Project Director :

Fiz. Mioara Iacob

Scientific coordination:

Dr. Mircea Udrea

Under Construction

Scientific and Technological Achievements

     Sol-gel HfO2 oxide thin films with high dielectric constant (high-k) were deposited on silicon, and new experimental data with respect to the phenomena of laser radiation interaction with mater were obtained. The results were published, presented at international conferences.

Published Papers

  1. Correlation between the method of preparation and the properties of the sol-gel HfO2 thin films"
    M. Zaharescu, V.S. Teodorescu, M. Gartner, MG. Blanchin ,A. Barau ,M. Anastasescu
    Journal of Non-Crystalline Solids, 354 (2-9), 409-415, 2008
  2. "Structure and dielectric properties of HfO2 films prepared by sol-gel method"
    M.G.Blanchin, B.Canut, Y. Lambert, V.S.Teodorescu, A.Barău, M.Zaharescu
    Journal of Sol-Gel Science and Technology, 47(2) 165-172, 2008
  3. "Fast and simple specimen preparation for TEM studies of oxide films deposited on silicon wafers"
    M.G.Blanchin Microscopy and Microanalysis 15, 15-19, 2009

Conferences & Workshops

  1. "Crystallization of sol-gel HfO2 thin films by pulsed laser annealing in UV"(oral presentation), authors:
    V.S.Teodorescu, C.Ghica, M-G.Blanchin, A.V.Maraloiu, A.Barău, M.Zaharescu, M. Dinescu, N. Scarisoreanu, M. Udrea
    EMRS 2008 Spring Meeting, symposium B, 26-30.05. 2008, Strasbourg, France.
  2. Localization of Mn2+ impurity ions in cubic ZnS quantum dots (oral presentation)
    S. V. Nistor, M. Stefan, L. C. Nistor and C. D. Mateescu
    Joint IFIN-HH-ICTP-IAEA Workshop on "Trends in nanoscience: theory, experiment, technology", August 23-30, 2009, Sibiu, Romania

Laboratory Networks

Under Construction

International Projects

Under Construction

Stages Activities Calendar
Stage I Activity 1. Methodologies and preliminary studies; laser irradiation set-up.
3 months, 2007
Stage II Activity 1. Laser processing of sol-gel HfO2 thin films
Activity 2. Laser densification and crystallization of HfO2 sol-gel films
12 months, 2008
Stage III Activity 1. Elaboration of nanostructured laser processed semiconductor ZnO thin films
Activity 2. p-type ZnO films obtained by laser irradiation in nitrogen
9 months, 2008 - 2009

Laboratory of Atomic Structures and Defects in Advanced Materials