The localization and crystallographic dependence of Si suboxide species at the SiO2/Si interface

Grunthaner, P. J.; Hecht, M. H.; Grunthaner, F. J.; Johnson, N. M.

doi:10.1063/1.338215

Cited by 292 publications

(140 citation statements)

References 22 publications

Supporting

Mentioning

123

Contrasting

Order By: Relevance

“…Many theoretical studies have attempted to reproduce or explain these statistics [6,9], but the interpretation is surprisingly subtle [14]. Nevertheless, there appears to be some concensus that the primary connection between Si and SiO 2 occurs via Si +2 [3,14], as in our model.…”

mentioning

confidence: 87%

See 1 more Smart Citation

Structure and Energetics of the Si-SiO2Interface

2000

View full text Add to dashboard Cite

Silicon has long been synonymous with semiconductor technology. This unique role is due largely to the remarkable properties of the Si-SiO 2 interface, especially the (001)-oriented interface used in most devices [1]. AlthoughSi is crystalline and the oxide is amorphous, the interface is essentially perfect, with an extremely low density of dangling bonds or other electrically active defects. With the continual decrease of device size, the nanoscale structure of the silicon/oxide interface becomes more and more important. Yet despite its essential role, the atomic structure of this interface is still unclear. Using a novel Monte Carlo approach, we identify low-energy structures for the interface. The optimal structure found consists of Si-O-Si "bridges" ordered in a stripe pattern, with very low energy. This structure explains several puzzling experimental observations. Experiments offer many clues to the interface structure, but their interpretation remains controversial, because of the complexities inherent in studying disordered materials. Proposed models range from a graded interface [2,3] to a sharp interface [4] and even to a crystalline oxide layer at the interface [5]. Most theoretical studies have involved guessing reasonable structures [6], sometimes even using hand-built models [7]. More recently, there have been attempts to obtain an unbiased structure using unconstrained molecular dynamics (MD) [8] and Monte Carlo (MC) studies [9]. However, because of kinetic limitations these studies have not been able to identify the equilibrium structure. Calculations of the interface energy are also not possible with existing methods.

show abstract

mentioning

confidence: 87%

“…Finally we note that in several experiments, photoemission has been used to measure the number of Si atoms at the interface having intermediate oxidation states [2,3,14]. Many theoretical studies have attempted to reproduce or explain these statistics [6,9], but the interpretation is surprisingly subtle [14].…”

mentioning

confidence: 99%

Structure and Energetics of the Si-SiO2Interface

2000

View full text Add to dashboard Cite

show abstract

“…Figure 3 shows O 1s XPS spectra of Si surface freshly etched by HF (Figure 3A) Figure 3C). The peaks at 531.8±0.1, 532.6±0.1 and 533.7±0.1 eV were assigned to SiO x , SiO 2 and SiOH, respectively 28,29 . Figure 3B shows that the exposure to an HF solution has removed most of SiO 2 and SiO x from the surface.…”

Section: Representative Resultsmentioning

confidence: 99%

Selective Area Modification of Silicon Surface Wettability by Pulsed UV Laser Irradiation in Liquid Environment

Liu

Moumanis

Dubowski

2015

JoVE

View full text Add to dashboard Cite

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of biosensing devices. We report on a protocol of using KrF and ArF lasers irradiating Si (001) samples immersed in a liquid environment with low number of pulses and operating at moderately low pulse fluences to induce Si wettability modification. Wafers immersed for up to 4 hr in a 0.01% H 2 O 2 /H 2 O solution did not show measurable change in their initial contact angle (CA) ~75°. However, the 500-pulse KrF and ArF lasers irradiation of such wafers in a microchamber filled with 0.01% H 2 O 2 /H 2 O solution at 250 and 65 mJ/cm 2 , respectively, has decreased the CA to near 15°, indicating the formation of a superhydrophilic surface. The formation of OH-terminated Si (001), with no measurable change of the wafer's surface morphology, has been confirmed by X-ray photoelectron spectroscopy and atomic force microscopy measurements. The selective area irradiated samples were then immersed in a biotin-conjugated fluorescein-stained nanospheres solution for 2 hr, resulting in a successful immobilization of the nanospheres in the non-irradiated area. This illustrates the potential of the method for selective area biofunctionalization and fabrication of advanced Si-based biosensing architectures. We also describe a similar protocol of irradiation of wafers immersed in methanol (CH 3 OH) using ArF laser operating at pulse fluence of 65 mJ/cm 2 and in situ formation of a strongly hydrophobic surface of Si (001) with the CA of 103°. The XPS results indicate ArF laser induced formation of Si-(OCH 3 ) x compounds responsible for the observed hydrophobicity. However, no such compounds were found by XPS on the Si surface irradiated by KrF laser in methanol, demonstrating the inability of the KrF laser to photodissociate methanol and create -OCH 3 radicals. Video LinkThe video component of this article can be found at

show abstract

“…For the PSi sample, two peaks are observed around 99 and 104 eV, which correspond to the bare Si (Si-Si) and SiO 2 peaks, respectively. 24 With increasing C n , the bare Si peak clearly decreases, and at the highest concentration (C n = 125 g/L), it completely disappears. This decrease suggests that at the higher NiCl 2 concentration, the surface of the PSi layer is more vigorously oxidized owing to the redox reaction between Si and Ni ions.…”

Section: A Composition and Morphology Of Ni/psi Powdersmentioning

confidence: 99%

Properties of magnetic nickel/porous-silicon composite powders

Nakamura

Adachi

2012

AIP Advances

View full text Add to dashboard Cite

The magnetic and photoluminescence (PL) properties of nickel/porous-silicon (Ni/PSi) composite powders are investigated. Ni/PSi composite powders are prepared by stain etching of Si powder in a HF/HNO3 solution followed by electroless plating of Ni nanoparticles on the stain-etched PSi powder in a NiCl2 solution. The Ni/PSi powders exhibit hydrophillicity, superparamagnetism caused by the deposited Ni nanoparticles, and orange-red PL owing to the nanostructured PSi surface. The degree of magnetization decreases with increasing Ni plating time, indicating its dependence on the size of the Ni nanoparticles. The Ni/PSi composite powders also show a stronger magnetization as compared to that of the Ni-particle-plated Si powder. The stronger magnetization results from the larger surface area of PSi. The PL intensity, peak wavelength, and lifetime of Ni/PSi are strongly dependent on the NiCl2 concentration. This dependence is due to the different thickness of the oxide overlayer on the PSi surface formed during the Ni plating process. The existence of the oxide overlayer also results in a small change in the PL intensity against excitation time

show abstract

The localization and crystallographic dependence of Si suboxide species at the SiO2/Si interface

Cited by 292 publications

References 22 publications

Structure and Energetics of the Si-SiO2Interface

Structure and Energetics of the Si-SiO2Interface

Selective Area Modification of Silicon Surface Wettability by Pulsed UV Laser Irradiation in Liquid Environment

Properties of magnetic nickel/porous-silicon composite powders

Contact Info

Product

Resources

About