Phase transition from Langmuir-type adsorption to two-dimensional oxide island growth during oxidation on Si(0 0 1) surface

Kinetics of Si atoms emission during the oxidation of Si(001) surfaces have been investigated using reflection high energy electron diffraction combined with Auger electron spectroscopy. The area ratio of the 1 × 2 and the 2 × 1 domains on a clean Si(001) surface changed with the oxidation of the surface by Langmuir-type adsorption. This change in the domain ratio is attributed to the emission of Si atoms. We can describe the changes in the domain ratio using the Si emission kinetics model, which states that (1) the emission rate is proportional to the oxide coverage, and (2) the emitted Si atoms migrate on the surface and are trapped at S B steps. Based on our model, we find experimentally that up to 0.4 ML of Si atoms are emitted during

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“…(1), which is constructed based on an oxidation reaction model of Langmuir-type adsorption. 8,9,12,14 …”

Section: Resultsmentioning

confidence: 99%

“…11,12 In particular, in Langmuir-type adsorption regions of passive oxidation where only oxide growth occurs, it has been proven both theoretically 13 as well as experimentally, 14 that oxygen can diffuse easily into Si dimer back-bonds. Diffusion of oxygen into dimer back-bonds causes a large strain.…”

Section: Introductionmentioning

confidence: 99%

Experimental estimation of oxidation-induced Si atoms emission on Si(001) surfaces

2015

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“…Oxidation experiments were performed by an integrated surface analysis apparatus equipped with facilities of UPS, reflection high energy electron diffraction combined with Auger electron spectroscopy (RHEED-AES), O 2 gas introduction and residual gas analysis [3,10]. The base pressure of the apparatus was $1 · 10 À8 Pa and UPS observation was achievable under an O 2 atmosphere up to $7 · 10 À2 Pa. A He-I resonance line (21.22 eV) was used as an excitation light for UPS.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…On the other hand, the dissociative adsorption reaction kinetics of O 2 and H 2 O on Si surfaces is also different from each other as follows. For Si(0 0 1)2 · 1 surface, O 2 adsorption is a first-order reaction with respect to the clean surface area (1 À h O ), where h O is the surface oxide coverage [2,3], while H 2 O adsorption is a zeroth-order reaction [4,5]. Upon exposing to H 2 O, dimer dangling bonds on the Si(0 0 1)2 · 1 surface are terminated with dissociative adsorption products of H and OH [5].…”

Section: Introductionmentioning

confidence: 99%

“…As a consequence of the large oxidation-induced strain, Si atoms are significantly emitted as observed as isolated dimers at RT by STM [9]. Therefore, it is necessary to investigate the O 2 adsorption reaction mechanism on Si surfaces from the viewpoint of the behavior of adsorbed O atoms and the adsorbed-oxygen-induced generation of point defects (emitted Si atoms + vacancies) [10] as well as from the conventional viewpoint of the reaction order and reaction rate [2,3]. Changes in work function, D/, are very sensitive to the lattice site and h O of adsorbed O atoms, especially with respect to the diffusion of adsorbed O atoms to the subsurface [10,11].…”

Section: Introductionmentioning

confidence: 99%

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Simultaneous observation of oxygen uptake curves and electronic states during room-temperature oxidation on Si(0 0 1) surfaces by real-time ultraviolet photoelectron spectroscopy

Ogawa¹,

Takakuwa²

2007

Surface Science

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Mechanisms of concurrent SiO desorption with oxide layer formation at Si(001) surface

Teraoka

Yoshigoe

Moritani

2008

Electrical Engineering Japan

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SUMMARYOxidation reactions at Si(001) surfaces have been studied via real-time in situ photoemission spectroscopy with synchrotron radiation for chemical bonding states of Si and O atoms and mass spectrometry for desorption of SiO molecules with supersonic O 2 molecular beams in a temperature region from 900 K to 1300 K. In our previous studies, the SiO desorption yield decreased with increasing incident energy in a temperature region from 900 K to 1000 K. In that case, the time evolutions of Si 2p photoemission spectra showed that SiO 2 structure on the surface was easily formed by the action of larger incident energy and the increased SiO 2 coverage correlated with the decreased SiO desorption yield. In this study, simultaneous measurements of Si 2p photoemission spectra and SiO desorption yield revealed that the decrease of SiO correlated with the increase of Si 2+ component, and the SiO desorption was terminated at the oxide thickness of 0.22 nm. These facts suggest that the SiO desorption takes place at the topmost Si dimers and a precursor for SiO desorption is a so-called T site, in which O atoms are bonding with the dangling bonds of the dimers. Consequently, M1 and M2 in the Dual-Oxide-Species (DOS) model have been clarified to be a T site and a Si 2+ state, respectively.

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Phase transition from Langmuir-type adsorption to two-dimensional oxide island growth during oxidation on Si(0 0 1) surface

Cited by 36 publications

References 22 publications

Experimental estimation of oxidation-induced Si atoms emission on Si(001) surfaces

Experimental estimation of oxidation-induced Si atoms emission on Si(001) surfaces

Simultaneous observation of oxygen uptake curves and electronic states during room-temperature oxidation on Si(0 0 1) surfaces by real-time ultraviolet photoelectron spectroscopy

Mechanisms of concurrent SiO desorption with oxide layer formation at Si(001) surface

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