Martin Setvín

Heterogeneous nucleation and adatom detachment at one-dimensional growth of In on Si(100)-2 X 1

Growth of atomic indium chains - 1D islands - on the Si(100)-2x1 surface was observed by scanning tunneling microscopy (STM) at room temperature and simulated by means of a kinetic Monte Carlo method. Density of indium islands and island size distribution were obtained for various deposition rates and coverage. STM observation of growth during deposition of indium provided information on growth kinetics and relaxation of grown layers. Important role of C-type defects at adsorption of metal atoms was observed. Measured growth characteristics were simulated using a microscopic model with anisotropic surface diffusion and forbidden zones along the metal chains. An analysis of experimental and simulation data shows that detachment of indium adatoms from the chains substantially influences a growth scenario and results in monotonously decreasing chain length distribution function at low coverage. Diffusion barriers determined from the simulations correspond to almost isotropic diffusion of indium adatoms on the surface. The results are discussed with respect to data reported in earlier papers for other metals.

Chemical identification of single atoms in heterogeneous III-IV chains on Si(100) surface by means of nc-AFM and DFT calculations.

Chemical identification of individual atoms in mixed In-Sn chains grown on a Si(100)-(2 × 1) surface was investigated by means of room temperature dynamic noncontact AFM measurements and DFT calculations. We demonstrate that the chemical nature of each atom in the chain can be identified by means of measurements of the short-range forces acting between an AFM tip and the atom. On the basis of this method, we revealed incorporation of silicon atoms from the substrate into the metal chains. Analysis of the measured and calculated short-range forces indicates that even different chemical states of a single atom can be distinguished.

Electronic structure of Bi lines on clean and H-passivated Si(100)

By means of scanning tunnelling microscopy and spectroscopy, we have investigated the electronic structure of Bi nanolines on clean and H-passivated Si(100) surfaces. Maps of the local density of states (LDOS) images of the Bi nanolines are presented for the first time. The spectra obtained for nanolines on a clean Si surface and the LDOS images agree with abxa0initio predicted spectra for the Haiku structure. For nanolines on a H-passivated surface, the spectra obtained suggest that the Bi nanoline may locally pin the surface Fermi level, and the LDOS images taken at low bias show a distribution of states different to what was expected at the Bi nanolines. The results are discussed with respect to use of the nanolines as atomic wire interconnections.

Kinetics of In growth on Si(100)2?1 surface at low coverage - STM study

Scanning tunneling microscopy (STM) was used for studying nucleation and growth of 1-dimensional indium islands (chains) at coverage below 0.5 ML on the reconstructed Si(100)2×1 surface at room temperature (RT). In-vivo measurements - direct observations of growth during deposition - provided data on growth kinetics and showed a substantial role of C-defects at adsorption of metal atoms. Density of the metal chains and distribution of the chain lengths were obtained for various amounts of deposited indium. The length of the indium chains was specified with atomic accuracy. The real time observations showed that surface mobility of indium atoms at RT is probably not entirely restricted by the forbidden zones accepted in previous growth models.