Arsenic‐terminated silicon and germanium surfaces studied by scanning tunnelling microscopy

Abstract

SUMMARY The epitaxial growth of As on the (111) and (100) faces of Si and the (111) face of Ge has been studied with vacuum tunnelling microscopy. The (111) faces of both semiconductors display a principally 1×1 termination, but differ with the presence of point defects on the Si(111): As‐1×1 surface and trenches separating large (∼ 100 Å) domains on the Ge(111): As‐1×1 surface. I‐V characteristics of the tunnel junction show a surface energy gap of approximately 1·9 eV for the Si(111): As‐1×1 surface and 0·9 eV for the Ge(111): As‐1×1 surface, in good agreement with recent theoretical calculations for these systems. As deposition on Si(001) results in a nominal 2×1 reconstruction of symmetric As dimers and elimination of missing dimer defects characteristic of the native Si(001) 2×1 surface. Further studies on vicinal, double‐stepped substrates shows the orientation of the dimers with respect to the substrate depends critically on the substrate temperature during the growth phase, with destruction of the single principle domain surface order occurring at temperatures in excess of 700°C.

A scanning tunneling microscopy study of As/Ge(mnn) and P/Ge(mnn) surfaces

“…For miscut orientations near (100) and (111), we find (100) and (111) terraces [1,2], in complete agreement with previously published results [3][4][5][6][7][8]. Prior to this study, little was known about the higher-angle miscuts, however.…”

“…Although this bonding configuration is very desirable chemically, it places the surface As atoms under tension [10]. It has been shown that this strain produces a network of threeatom-wide trenches [7,8]. The AsH 3 :Ge(111) surfaces we have observed are quite similar and contain all of the same basic features.…”

“…As/Ge(111) surfaces formed by As 4 exposure under UHV consist of a simple 1 × 1 reconstruction in which As atoms terminate the Ge bulk lattice [7][8][9]. Each As atom is bonded to three Ge atoms, leaving a lone electron pair protruding away from the surface.…”

High-quality III–V semiconductor MBE growth on Ge/Si virtual substrates for metal-oxide-semiconductor device fabrication

“…However, arsenic atoms tend to interact with Si or Ge surfaces and change surface reconstructions to reduce the number of dangling bonds [24,25]. Several researchers have reported As-As dimers form on the Si surface [25][26][27]. Some of these results are, however, contradictory in defining which growth condition produces different orientations of As dimers (perpendicular or parallel to the step edges) on vicinal Si surfaces.…”

Selective area metalorganic vapor-phase epitaxy of gallium arsenide on silicon

“…with all double-height steps, so as to prevent anti-phase domains from forming. This structure has been obtained by several groups on single-domain Si (1 0 0) starting surfaces [27][28][29]. However, obtaining a single-domain As-passivated structure on Si (1 0 0) surfaces that are not originally single domain is difficult.…”