Ge molecular beam epitaxy on Si(113): surface structures, nanowires and nanodots

Abstract

By performing epitaxial growth of Ge on Si(113) layer by layer, observed using scanning tunnelling microscopy, we show the Ge/Si(113) surface structure and island shape transition with an increase of Ge coverage and we discuss the transition in terms of epitaxial stress evolution and relaxation of the epitaxial morphologies. Nanofeatures of Ge epitaxial islands, such as nanowires and nanodots, are highlighted.

Study of H:Si(113)2&times;2 Structure by Scanning Tunneling Microscopy and <i>Ab Initio</i> Calculation

“…The surface structure is the 2×n (n = 2, 3) phase, which corresponds to previous research [19,22]. One-dimensional islands that grow toward the [1][2][3][4][5][6][7][8][9][10] direction are observed locally [black arrow in Fig. 2(a)].…”

“…3(a), three types of protrusion (defined as α, β, and γ protrusions) are observed in the 2×2 phase (defined as 2×2:H structure). The α and γ protrusions are ball-shaped, and the interval is 0.38 nm toward the [1][2][3][4][5][6][7][8][9][10] direction. The β protrusion is elliptical, and the interval is 0.80 nm toward the [1][2][3][4][5][6][7][8][9][10] direction.…”

“…At a high substrate temperature, the 2×n reconstructed structures tend to be formed by adsorption of metal atoms and molecules of gas [5][6][7][8][9][10][11][12][13][14][15]. This surface structure often leads to formation of one-dimensional structures: nanowires and nanodots [5][6][7][8][9][10][11][12]. This is assumed to be caused by the anisotropic surface strain of the surface structure [12,13].…”

“…Furthermore, the effect of the substrate anisotropy characteristic of high-index surfaces often appears during epitaxial growth. In addition, one-dimensional structures called nanowires are formed as a result of the adsorption of metal atoms on a Si(113) surface [5][6][7][8][9][10][11][12][13]. Therefore, the Si(113) surface has also attracted increasing interest due to possible application as the substrate in nanostructure fabrication, and the adsorption structure of metal atoms and gas molecules on this surface has been studied [14][15][16].…”

One-dimensional electronic structure of the Sb-decorated Si(113)2×2 surface

“…For this reason, the 1D growths reported on Si(1 1 3) [14,15] may be based on the intrinsic anisotropy of the unreconstructed Si(1 1 3)1 · 1 structure rather than one of the reconstructed 3 · 2 structure.…”