Solid Phase Epitaxy Process Of Ar-Ion Bombarded Silicon Surfaces and Recovery of Crystallinity by Thermal Annealing Observed With Scanning Tunneling Microscopy

1993 ◽  
Vol 321 ◽  
Author(s):  
Katsuhiro Uesugi ◽  
Masamichi Yoshimura ◽  
Takafumi Yao
Keyword(s):  
Thermal Annealing ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Amorphous Layer ◽  
Silicon Surfaces ◽  
Scanning Tunneling ◽  
Layer By Layer ◽  
Solid Phase Epitaxy ◽  
Tunneling Microscopy ◽  
Reconstructed Surface

ABSTRACTThe solid-phase epitaxy (SPE) process of Ar+-ion bombarded Si (001) surfaces and recovery of crystallinity by thermal annealing are studied “in situ” by using a scanning tunneling Microscope (STM). As-bombarded surfaces consist of grains of 0.63–1.6 nm in diameter. The grains gradually coalesce and form clusters of 2–3.6 nm in diameter at annealing temperature of 245° C (2×1) and (1×2) reconstructed regions surrounded by amorphous regions are partially observed on the surface by prolonged annealing, which suggests the onset of SPE. Successive observation reveals that the smoothing of the surface occurs layer by layer. As annealing temperature is raised up to 445 °C, the amorphous layer epitaxially crystallizes up to the topmost surface, and (2×1) reconstructed surface with Monatomic-height steps is observed. The smoothing of the surface structures and the formation of nucleation of Si islands are observed during annealing at 500 °C.

Stm Observation of Solid Phase Epitaxy Processes of Ar-Sputtered Si(100) Surfaces

1992 ◽  
Vol 280 ◽  
Author(s):  
Katsuhiro Uesugi ◽  
Masamichi Yoshimura ◽  
Takafumi Yao ◽  
Tomoshige Sato ◽  
Takashi Sueyoshi ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Scanning Tunneling Microscopy ◽  
Double Layer ◽  
Solid Phase ◽  
The Other ◽  
Scanning Tunneling ◽  
Nanometer Scale ◽  
Solid Phase Epitaxy ◽  
Tunneling Microscopy ◽  
Partially Observed

ABSTRACTScanning tunneling microscopy (STM) is used to investigate the surface morphology of Ar+-ion bombarded Si(100) surfaces and to elucidate the very beginning stages of solid phase epitaxy (SPE) processes of the Ar+-ion bombarded Si surfaces. The Ar+-ion bombarded Si surface consists of hillocks of 1–2 nm in diameter and 0.35–0.75 nm in height. The onset of SPE initiates at around 590°C, at which temperature a (2×2) structure surrounded by amorphous regions is partially observed on terraces of the surface. During annealing at 590–620°C, the areas of the c(2×2) and c(4×4) reconstruction surrounded by amorphous regions develops. New defect models for the (2×2) and c(4×4) structures are proposed w here alternating arrangements of the buckled dimers together with missing dimer defects are considered. On the other hand, after thermal annealing of the Ar+-ion bombarded Si at 830°C for 10 sec, terraces of (2×1) and (1×2) orientations arc observed on the surface, and pyramidal structures on a nanometer-scale which consists of double-layer step edges (dimer rows perpendicular to terrace edge) arc observed.

Evolution and Degeneration of Dimer-Adatom-Stacking-Fault Structure in Solid-Phase Epitaxy on Si(111) Surface Observed by Scanning Tunneling Microscopy

1998 ◽  
Vol 05 (01) ◽  
pp. 21-25
Author(s):  
Z. Zhang ◽  
M. A. Kulakov ◽  
B. Bullemer
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Solid Phase ◽  
Stacking Fault ◽  
Structure Evolution ◽  
Scanning Tunneling ◽  
Solid Phase Epitaxy ◽  
Dangling Bonds ◽  
Tunneling Microscopy ◽  
Fault Structure ◽  
Unit Cells

Large unit cells of dimer-adatom-stacking-fault structure and related 2 × 2 and c(4 × 2) reconstructions have been prepared by low-temperature solid-phase epitaxy and observed by scanning tunneling microscopy. The size-different unit cells of the DAS structure are considered to be a structure evolution in which more electron charge transfers in a larger unit cell from the adatom dangling bonds to the rest-atom dangling bonds. In some cases the DAS structure can degenerate into triangular 2 × 2 domains and bundlinke c(4 × 2) domains. The rest atoms are always fully filled by electrons due to the charge transfer. The adatom dangling bonds are partially filled in a c(4 × 2) symmetry and essentially empty in a 2 × 2 symmetry. As a result, the rest atoms in 2 × 2 domains can be imaged without the adatom protrusions while in the c(4 × 2) domains the protrusions of the adatoms and the rest atoms appear in zigzag chains, when the sample is negatively biased.

Surface studies of phase formation in Co–Ge system: Reactive deposition epitaxy versus solid-phase epitaxy

2001 ◽  
Vol 16 (3) ◽  
pp. 744-752 ◽  
Author(s):  
I. Goldfarb ◽  
G. A. D. Briggs
Keyword(s):  
Lattice Constant ◽  
Solid Phase ◽  
Morphological Evolution ◽  
Three Dimensional ◽  
High Energy ◽  
Scanning Tunneling ◽  
Solid Phase Epitaxy ◽  
Wetting Layer ◽  
Tunneling Microscopy ◽  
Reactive Deposition

Morphological evolution of cobalt germanide epilayers, CoxGey, was investigated in situ by scanning tunneling microscopy and spectroscopy and reflection high-energy electron diffraction, as a function of deposition method and, hence, the phase content of the epilayer. During reactive deposition epitaxy, in which Co atoms were evaporated onto a flat pseudomorphic Ge/Si(001) wetting layer at 773 K, the first phase formed was cobalt digermanide, CoGe2, in the form of elongated pyramidal islands. Each of these three-dimensional islands has locally exerted an additional strain on the Ge wetting layer already strained at the Ge/Si(001) interface, lifting the layer metastability and causing, in turn, the formation of three-dimensional Ge pyramids underneath every CoGe2 island. Solid-phase epitaxy of Co onto the same Ge/Si(001) epilayer resulted in the formation of more Co-rich germanide islands. Coupling of strain from these germanides to the epitaxial Ge/Si(001) strain has also facilitated a two-dimensional-to-three-dimensional transition of the Ge layer, however, with the germanide islands located at the Ge pyramid troughs, rather than crests. The difference in the relative location of germanide and germanium islands in these two cases is explained by accommodation of the large lattice-constant germanides at the more relaxed regions of the Ge pyramid crests and the smaller lattice-constant at the compressed Ge pyramid troughs.

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