Self-assembled nanowires on semiconductor surfaces

Abstract

A number of different families of nanowires which self-assemble on semiconductor surfaces have been identified in recent years. They are particularly interesting from the standpoint of nanoelectronics, which seeks non-lithographic ways of creating interconnects at the nanometre scale (though possibly for carrying signal rather than current), as well as from the standpoint of traditional materials science and surface science. We survey these families and consider their physical and electronic structure, as well as their formation and reactivity. Particular attention is paid to rare earth nanowires and the Bi nanoline, both of which self-assemble on Si(001).Comment: 32 pages, 30 figure

Pb chains on reconstructed Si(335) surface

“…The DZP utilizes two radial functions for each angular momentum and additional polarization shell. The radii of the orbitals for different species were following (in Bohrs): Si -5.13 (3s), 6.59 (3p) and 5.96 (3d), Au -4.39 (5d), 6.24 (6s) and 5.79 (6p), Pb -3.56 (5d), 4.68 (5f ), 5.30 (6s) and 6.48 (6p), and H -5.08 (1s) and 4.48 (2p). A Brillouin zone sampling of 24 nonequivalent k points, and a real-space grid equivalent to a planewave cutoff 100 Ry (up to 82 k points and 300 Ry in the convergence tests) have been employed.…”

The Energetics of Hut-Cluster Self-Assembly in Ge/Si(001) from Linear-Scaling DFT Calculations

“…), but our understanding of the underlying processes is limited. In the initial stages of growth, structures which are metastable and whose formation is dominated by kinetic effects can often form before the energetically stable structure; 1) this is particularly true on semiconductor surfaces where the interplay between strain and electronic energies compete to give a rich variety of one-dimensional 2) and two-dimensional (2D) structures.3) Atomistic modeling based on electronic structure theory has a key role to play in this area, but progress depends on addressing a number of issues, including accuracy, the scaling of computer effort with system size, the control of computational artefacts, and the sampling of energetically competing geometries. The much studied system of self-assembled Ge hut clusters on Si (001) 4,5) serves as a paradigm where modeling encounters all these issues.…”

“…), but our understanding of the underlying processes is limited. In the initial stages of growth, structures which are metastable and whose formation is dominated by kinetic effects can often form before the energetically stable structure; 1) this is particularly true on semiconductor surfaces where the interplay between strain and electronic energies compete to give a rich variety of one-dimensional 2) and two-dimensional (2D) structures.…”

Time-dependent annealing and deposition on substrates with repulsive interactions

“…The growth of nanowires is of considerable current interest [26][27][28] . Thus we are interested in the conditions under which these wires may grow.…”