| CZECH NANO TEAM | Physics of Nanostructures and Nanotechnologies

Tomáš Šikola

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Group subject:

Nanolithography by SPM

Name and Curriculum vitae of contact person:

Tomáš Šikola (Assoc. Prof., RNDr., CSc.)

Affiliation:

Institute of Physical Engineering, Brno University of Technology

Position - Head of the division of Solid State/ Thin Films Physics and Surface Science

Fields of scientific activity:

Thin Films Physics, Surface Science, Nanotechnology:

• Application of STM/AFM for building nanostructures, a study of electrical properties of nanostructures.

• Study of interaction of local SPM probes with surfaces Ion-beam assisted deposition (IBAD) of metal-, oxide- and nitride- thin films/multilayers

• Ion-beam modification and etching of micro/nanostructures by ion beams

• UHV molecular beam deposition of ultrathin films (superstructures/ ultra-thin films - Ga, GaN, SiN)

• Study of interaction of ions, atoms and molecules with surfaces

• Development of in situ surface analytical methods – STM/AFM, SIMS, TOF LEIS, XPS, LEED

• UHV technique

The supervisor of 32 successully defended diploma thesis and 2 PhD thesis

Publications:

Author or co-author of more than 80 scientific publications (23 published in international journals)

Leave of absence (selected):

• In 1992 - visiting scientist at the University of Salford (U.K.), 6 months (Prof. D. G. Armour)

• In 1993 - visiting scientist at the Eindhoven University of Technology (NL), 6 months (Prof. H. H. Brongersma)

• In 1994 - visiting scientist at Aston University (U.K.) , 2 months (Prof. J. L. Sullivan)

• In 1998 - visiting scientist at the University of Salford (U.K.), 3 months (Prof. D. G. Armour)

• In 2000 - visiting professor at the Arizona State University, 2 months (Prof. I. S. T. Tsong)

• In 2002 - visiting scientist at TU Vienna, 1 month (Prof. P. Varga)

Selected international projects:

• EC - COPERNICUS - CIPA - CT94 – 0224, (1994–1996) „Development of In-situ Monitoring Technologies for the Control of Advanced Surface Processing System“

• Kontakt-ME 334 (MŠMT-NSF, 1999 – 2001) „Synthesis of GaN epitaxial layers.“

• Kontakt/Aktion -ME536 ( 2001 - 02) „Application of Scanning Tunneling Microscopy and Spectroscopy for the study of atomic surface structures“

Other activities:

• the coordinator of the two EU TEMPUS projects No. JEP-02559-91 and No. JEN -02559 CZ in the field of advanced material technologies (1991-94 and 1995-96, respectively)

• one of the two priciple organizers of the four international summer schools held at Tři Studně (CR) on thin films, surfaces and nanotechnologies (1993, 1996, 1999, and 2002)

Selected related publications from last 5 years:

• T. Šikola, J. Spousta, L. Dittrichová, M. Stránský, J. Zlámal, F. Matějka, A. Nebojsa, J. Zemek, V. Peřina, D. Rafaja, and L. Ranno: Deposition of Magnetic Thin Films by IBAD, Nuclear Instr. Methods B 148, 1-4, 907 – 911(1999)

• R. Roučka, J. Jiruše, and T. Šikola: Spot Intensity Processing in LEED Images, Vacuum 65 (2), 121 - 126 (2002)

• R. Kalousek, F. Lopour, P. Dub and T. Šikola: Vibrational Analysis of the Cantilever in Noncontact Scanning Force Microscopy, Surface and Interface Analysis 30 (1), 292 - 296 (2000)

• F. Lopour, R. Kalousek, D. Škoda, J. Spousta, F. Matějka, and T. Šikola: Application of AFM in Microscopy and in Fabrication of Micro/Nanostructures, Surface and Interface Analysis 34 (1), 352 - 355 (2002)
• S. Voborný, M. Kolíbal, J. Mach, J. Čechal, P. Bábor, S. Průša, J. Spousta, and T. Šikola: Deposition and In-Situ characterization of Ultra Thin Films, Thin Solid Films, in print.

Group members:

Tomáš Šikola, Radek Kalousek, Jiří Spousta, P. Dub, David Škoda, Filip Lopour, Miroslav Bartošík, Klára Maturová, Vít Křenek, Ondřej Tomanec, Petr Kostelník, Petr Bábor, Vladan Buš, Libuše Dittrichová, Stanislav Voborný, Jiří Vais, Stanislav Průša, Miroslav Kolíbal, Jindřich Mach

Main Research Subjects:

Using nanolithography carried out by a scanning probe microscope (SPM) one can reach a resolution that may exceed the standard of other lithographic processes and, contrary to them, under optimum conditions (UHV) to carry out atom manipulation by the same instrument as well (scanning tunneling microscopes - STM). Although a variety of SPM nanolithography methods have been demonstrated, they are still at the early stage of their development, without no direct comparison and systematisation and limited to laboratory-scale research. On the other hand, by this technique nanoelements of specific sizes and shapes can be built and, hence, their properties as the function of these parameters studied. There are two major tasks: (i) to develope reliable techniques for building nanoelements and arrays of them by SPM and some supportive techniques (e.g. ultrathin-film deposition), and (ii) to study fundamental properties of nanostructures on these model systems.

Properties to be studied: quantum transport phenomena (quantum conductance steps, tunneling effects, Coulomb blockade, etc.).on assembly of nanoelements and nanodevices (conducting channels, insulating barriers, SETs); plasmon-polariton coupling and local properties of the nanoelements (e.g. LDOS) in the metallic nanoparticle chains; integral and local (photo)luminiscence properties of regular arrays of semiconductor nanoelements; ability of nanocontacts to inject charge carriers into molecular nanostructures and devices, etc.

Selected Specific Equipment:

The SPM nanolithography can be carried out both under ambient conditions with a commercial STM/AFM (AutoProbe, VEECO) and under UHV conditions by a home-built STM/AFM unit installed into a complex UHV apparatus. In case of both microscopes, arbitrary nanopatterns can be drawn using special software codes for nanolithography.

A HV apparatus with two Kaufman ion beam sources can be used for ion-beam etching (transfer of nanopatterns prepared by SPM into the films) and ion beam assisted deposition of ultra-thin films (lift-off technique). A complex UHV apparatus, comprising UHV STM/AFM unit, accommodates the techniques for ion-beam assisted molecular beam evaporation of ultra thin films, and their in-situ analysis (TOF-LEIS, XPS, SIMS, LEED/AES, spectroscopic ellipsometry; except XPS and LEED/AES all the techniques built in the group).

To study photonic and optoelectronic properties of nanostructures, an optical microscope (Nicon) coupled with a fibre spectrophotometer (Ocean) will be used. An imaging spectrophotometer for photoluminiscence properties of single nanodots will be available as well.

Additional recent selected publications by group members:

• J. Jiruše, T. Šikola, and P. Dub: Application of Simple Kinematic Predictions for the Structural Search in LEED, Vacuum 55 (1999), 141 - 146

• F. Lopour, P. Bábor, T. Šikola, J. Spousta, L. Dittrichová, F. Matějka, and J. C. C. Duarte: Etching of Microstructures and Modification of Solid Surfaces by Low Energy Ion Beams, Proc. of the 3rd International Conference MicroMat 2000, Berlin 2000, editors B. Michel, T. Winkler, M. Werner, and H. Fecht, 919 - 922

• P. Dub and O. Litzman: A note on the problem of scattering from a single atomic plane and a stack of planes. Differences between the Ewald an dother diffraction theories. ACTA CRYSTALL. A 57, 212-216 (2001)

• P. Dub and O. Litzman: Is the border surface of a crystal indeed the weakest point of the dynamical theory of diffraction? ACTA CRYSTALL. A55, 686-689 (2001)

• R. Roučka, J. Jiruše, and T. Šikola: Spot Intensity Processing in LEED Images, Vacuum 65 (2), 121 -126 (2002)

• P. Tichopádek, A. Nebojsa, J. Čechal, P. Bábor, P. Jurkovič, K. Navrátil, and T. Šikola: A Study of Thin Oxide Films by Ellipsometry and AR XPS, Surface and Interface Analysis 34 (1), 2002, 531 – 534

• T. Šikola, F. Lopour, R. Kalousek, D. Škoda, P. Bábor, V. Buš, and J. C. C. Duarte: Application of SPM in Surface Studies and Nanotechnology, Fine Mechanics and Optics, Nr. 6 – 7, 210 -213 (2002)

• J. Spousta, M. Urbánek, R. Chmelík, J. Jiruše, J. Zlámal, K. Navrátil, A. Nebojsa, and T. Šikola: In Situ Measurements of Surface Homogeneity of Optical Parameters of Weakly Absorbing Thin Films, Surface and Interface Analysis 34 (1), 664 – 667 (2002).