Heterogeneous nucleation and adatom detachment at one-dimensional growth of In onSi(100)−2×1

Abstract

Growth of atomic indium chains -1D islands -on the Si(100)-2×1 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.

Scale invariance of continuum size distribution upon irreversible growth of surface islands

“…This result is important from the fundamental point of view and can serve as an explanation of scalability of experimental DFs of lin ear chains of In adatoms on a reconstructed Si(100)-2 × 1 surface [12], as well as in the case of other metals [13,14]. At the same time, we note that the "triangle" DF shape typical for the continuum approximation with the first derivative with respect to size [17] strongly differs in its shape from the spectrum obtained based on exact discrete BKEs in the same problem [13,14].…”

“…This concerns, in particular, methods for constructing analytical DFs based on balance kinetic equations (BKEs) [6][7][8][9][10][11], approximations of capture coefficients as a function of the island size beyond the mean field approximation [3][4][5]9], comparative analysis of the homogeneous and heterogeneous growth [12][13][14], and the applica bility of BKEs for describing DFs of one dimensional…”

“…chains of adatoms [12,14] and nonplanar structures of the type of filamental nanocrystals [15,16]. In con trast to the theory of nucleation with the decay of par ticles, where DFs are rather symmetric [17][18][19][20], DFs in irreversible growth models acquire a pronounced asymmetry with a long tail in the region of small sizes [8,11].…”

Analytic scaling function for island-size distributions

“…Linear and © -independent correlation as = a + s in the REs has been considered once [29] in the case o f heterogeneous nucleation. Such a size linearity o f the capture rates yields sim ple analytic ISDs in the form o f a Polya (or G am m a) distribution w hich autom atically acquires the scaling form in the continuum lim it [29], On the other hand, purely heterogeneous nucleation, for exam ple, form ation o f linear chains o f metal adatom s on (2 x 1 (-reconstructed Si(100) surfaces with a high concentration o f C-type defects [30,31], applies only to som e growth scenarios and is not a general situation studied for the scaling behavior o f the ISDs.…”

Quantum Size Effect and Electronic Stability of Freestanding Metal Atom Wires

“…Usually, surfaces with a periodic step structures like vicinal metal or semiconductor surfaces are employed in molecular beam epitaxy to fabricate arrays of atom wires. Once adatoms diffuse anisotropically on these surfaces, well-ordered 1-D atom wires are possibly self-assembled [16,17].…”