Understanding GaAs Native Oxides By Correlating Three Liquid Contact Angle Analysis (3LCAA) and High Resolution Ion Beam Analysis (HR-IBA) to X-Ray Photoelectron Spectroscopy (XPS) as Function of Surface Processing

ABSTRACTChemical bonding in native oxides of GaAs, before and after etching, is detected by X-Ray Photoelectron Spectroscopy (XPS). It is correlated with surface energy engineering (SEE), measured via Three Liquid Contact Angle Analysis (3LCAA), and oxygen coverage, measured by High Resolution Ion Beam Analysis (HR-IBA).Before etching, GaAs native oxides are found to be hydrophobic with an average surface energy, γT, of 33 ± 1 mJ/m2, as measured by 3LCAA. After dilute NH4OH etching, GaAs becomes highly hydrophilic and its surface energy, γT, increases by a factor 2 to a reproducible value of 66 ± 1 mJ/m2. Using HR-IBA, oxygen coverage on GaAs is found to decrease from 7.2 ± 0.5 monolayers (ML) to 3.6 ± 0.5 ML. The 1.17 ratio of Ga to As, measured by HR-IBA, remains constant after etching.XPS is used to measure oxidation of Ga and As, as well as surface stoichiometry on two locations of several GaAs(100) wafers before and after etching. The relative proportions of Ga and As are unaffected by adventitious carbon contamination. The 1.16 Ga:As ratio, measured by XPS, matches HR-IBA analysis. The proportions of oxidized Ga and As do not change significantly after etching. However, the initial ratio of As2O5 to As2O3, within the oxidized As, significantly decreases after etching from approximately 3:1 to 3:2.Absolute oxygen coverage, as a function of surface processing, is determined within 0.5 ML by HR-IBA. XPS offers insight into these modifications by detecting electronic states and phase composition changes of GaAs oxides. The changes in surface chemistry are correlated to changes in hydro-affinity and surface energies measured by 3LCAA.

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Measuring Surface Energies of GaAs (100) and Si (100) by Three Liquid Contact Angle Analysis (3LCAA) for Heterogeneous Nano-BondingTM

MRS Advances ◽

10.1557/adv.2018.529 ◽

2018 ◽

Vol 3 (57-58) ◽

pp. 3403-3411 ◽

Cited By ~ 2

Author(s):

Christian E. Cornejo ◽

Michelle E. Bertram ◽

Timoteo C. Diaz ◽

Saaketh R. Narayan ◽

Sukesh Ram ◽

...

Keyword(s):

Contact Angle ◽

Surface Engineering ◽

Ion Beam ◽

Van Der Waals ◽

Native Oxides ◽

Boron Doped ◽

Measuring Surface ◽

Beam Analysis ◽

Oxygen Coverage ◽

Contact Angle Analysis

ABSTRACTAnalysis of the total surface energy γTand its three components as established by the van Oss-Chaudhury-Good Theory (vOCG) is conducted via Three Liquid Contact Angle Analysis (3LCAA). γTis correlated with the composition of the top monolayers (ML) obtained from High-Resolution Ion Beam Analysis (HR-IBA). Control of γTenables surface engineering for wafer bonding (Nano-BondingTM) and/or epitaxial growth. Native oxides on boron-doped p-Si(100) are found to average γTof 53 ± 1.4 mJ/m2) and are always hydrophilic. An HF in methanol or aqueous HF etch for 60 s always renders Si(100) hydrophobic. Its γTdecreases by 20% to 44 ± 3 mJ/m2in HF in methanol etch and by 10% to 48 ± 3 mJ/m2in aqueous HF. On the contrary, GaAs(100) native oxides are found to always be hydrophobic. Tellurium n+-doped GaAs(100) yields an average of γTof 37 ± 2 mJ/m2, 96% of which is due to the Lifshitz-Van der Waals molecular interactions (γLW= 36 ± 1 mJ/m2). However, hydrophobic GaAs(100) can be made highly hydrophilic. After etching, γTincreases by almost 50% to 66 ± 1.4 mJ/m2. 3LCAA shows that the γTincrease is due to electron acceptor and donor interactions, while the Lifshitz-van der Waals energy γLWremains constant. IBA combining the 3.039 ± 0.01 MeV oxygen nuclear resonance with <111> channeling, shows that oxygen on Si(100) decreases by 10% after aqueous HF etching, from 13.3 ± 0.3 monolayers (ML) to 11.8 ± 0.4 ML 1 hour after etch.Te-doped GaAs(100) exhibits consistent oxygen coverage of 7.2 ± 1.4 ML, decreasing by 50% after etching to a highly hydrophilic surface with 3.6 ± 0.2 oxygen ML. IBA shows that etching does not modify the GaAs surface stoichiometry to within 1% . Combining 3LCAA with HR-IBA provides a quantitative metrology to measure how GaAs and Si surfaces can be altered to a different hydroaffinity and surface termination.

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Comparative Study of Surface Energies of Native Oxides of Si(100) and Si(111) via Three Liquid Contact Angle Analysis

MRS Advances ◽

10.1557/adv.2018.473 ◽

2018 ◽

Vol 3 (57-58) ◽

pp. 3379-3390 ◽

Cited By ~ 5

Author(s):

Saaketh R. Narayan ◽

Jack M. Day ◽

Harshini L. Thinakaran ◽

Nicole Herbots ◽

Michelle E. Bertram ◽

...

Keyword(s):

Contact Angle ◽

Surface Energy ◽

Sessile Drop ◽

Surface Composition ◽

Ion Beam ◽

Contact Angles ◽

Van Der Waals Interactions ◽

Native Oxides ◽

Relative Errors ◽

Contact Angle Analysis

ABSTRACTThe effects of crystal orientation and doping on the surface energy, γT, of native oxides of Si(100) and Si(111) are measured via Three Liquid Contact Angle Analysis (3LCAA) to extract γT, while Ion Beam Analysis (IBA) is used to detect Oxygen. During 3LCAA, contact angles for three liquids are measured with photographs via the “Drop and Reflection Operative Program (DROP™). DROP™ removes subjectivity in image analysis, and yields reproducible contact angles within < ±1°. Unlike to the Sessile Drop Method, DROP can yield relative errors < 3% on sets of 20-30 drops. Native oxides on 5 x 1013 B/cm3 p- doped Si(100) wafers, as received in sealed, 25 wafer teflon boats continuously stored in Class 100/ISO 5 conditions at 24.5°C in 25% controlled humidity, are found to be hydrophilic. Their γT, 52.5 ± 1.5 mJ/m2, is reproducible between four boats from three sources, and 9% greater than γT of native oxides on n- doped Si(111), which averages 48.1 ± 1.6 mJ/m2 on four 4” Si(111) wafers. IBA combining 16O nuclear resonance with channeling detects 30% more oxygen on native oxides of Si(111) than Si(100). While γT should increase on thinner, more defective oxides, Lifshitz-Van der Waals interactions γLW on native oxides of Si(100) remain at 36 ± 0.4 mJ/m2, equal to γLW on Si(111), 36 ± 0.6 mJ/m2, since γLW arises from the same SiO2 molecules. Native oxides on 4.5 x 1018 B/cm3 p+ doped Si(100) yield a γT of 39 ± 1 mJ/m2, as they are thicker per IBA. In summary, 3LCAA and IBA can detect reproducibly and accurately, within a few %, changes in the surface energy of native oxides due to thickness and surface composition arising from doping or crystal structure, if conducted in well controlled clean room conditions for measurements and storage.

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THE NEW LOW ENERGY ION BEAM ANALYSIS FACILITY AT MAPUTO UNIVERSITY

International Journal of PIXE ◽

10.1142/s0129083595000289 ◽

1995 ◽

Vol 05 (04) ◽

pp. 249-253

Author(s):

R.J. UTUI ◽

N.P.O. HOMMAN ◽

K.G. MALMQVIST

Keyword(s):

Ion Beam ◽

Low Energy ◽

Proton Accelerator ◽

Nuclear Reaction Analysis ◽

Beam Diagnostics ◽

Ion Beam Analysis ◽

X Ray ◽

Beam Analysis ◽

Set Up ◽

Eduardo Mondlane University

A new Ion Beam Analysis (IBA) facility which was recently installed in the Department of Physics of the Eduardo Mondlane University of Maputo, Mozambique, is described. The set up is based on a low energy (500 keV) Van de Graaff proton accelerator and is intended to be used in particle induced X-ray emission (PIXE), Rutherford Backscattering (RBS) and nuclear reaction analysis (NRA). Preliminary experiments on beam diagnostics were performed successfully and the followed procedure is described.

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Aluminium incorporation in AlxGa1−xN/GaN heterostructures: A comparative study by ion beam analysis and X-ray diffraction

Thin Solid Films ◽

10.1016/j.tsf.2008.04.069 ◽

2008 ◽

Vol 516 (23) ◽

pp. 8447-8452 ◽

Cited By ~ 10

Author(s):

A. Redondo-Cubero ◽

R. Gago ◽

F. González-Posada ◽

U. Kreissig ◽

M.-A. di Forte Poisson ◽

...

Keyword(s):

Comparative Study ◽

Ion Beam ◽

X Ray Diffraction ◽

Ion Beam Analysis ◽

X Ray ◽

Beam Analysis

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A high resolution magnetic spectrograph for ion beam analysis

Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms ◽

10.1016/0168-583x(96)00259-5 ◽

1996 ◽

Vol 118 (1-4) ◽

pp. 566-572 ◽

Cited By ~ 35

Author(s):

W.M. Arnoldbik ◽

W. Wolfswinkel ◽

D.K. Inia ◽

V.C.G. Verleun ◽

S. Lobner ◽

...

Keyword(s):

High Resolution ◽

Ion Beam ◽

Ion Beam Analysis ◽

Beam Analysis

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AIR PARTICULATE RESEARCH CAPABILITY AT THE NEW ZEALAND ION BEAM ANALYSIS FACILITY USING PIXE AND IBA TECHNIQUES

International Journal of PIXE ◽

10.1142/s0129083505000581 ◽

2005 ◽

Vol 15 (03n04) ◽

pp. 249-255 ◽

Cited By ~ 25

Author(s):

W. J. TROMPETTER ◽

A. MARKWITZ ◽

P. DAVY

Keyword(s):

Particulate Matter ◽

New Zealand ◽

Limit Of Detection ◽

Ion Beam ◽

Anthropogenic Sources ◽

Ion Beam Analysis ◽

Air Particulate Matter ◽

X Ray ◽

Air Particulate ◽

Beam Analysis

PIXE and Ion Beam Analysis are one of the few techniques that can be used to identify the elemental composition of air particulates without destroying the filter sample. They are key tools for identifying the sources and determining the relative contribution of biogenic and anthropogenic sources of air particulate matter pollution in our environment. Over the last 8 years, specialised equipment has been designed and built at the New Zealand Ion Beam Analysis facility in Lower Hutt for semi automated analysis of air filters. The equipment and experimental techniques have been refined to improve sensitivities for many of the elements in the periodic table. At GNS, sensitivities have recently been further improved by using two X-ray detectors simultaneously with different amounts of X-ray filtering and collimation. The average limit of detection is improved from 66 ng/cm2 (typical for a setup using a single detector) to 35 ng/cm2 using two detectors simultaneously. The New Zealand Ion Beam Analysis facility now routinely analyses air particulate matter collected on filters from several locations around New Zealand. In this paper, results of air particulate studies from several locations in the Wellington region are presented.

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Fundamentals and Present Aspects of Ion Beam Technology. IV. Ion Beam Analysis. 1. Ion-induced X-ray emmission spectrometry.

RADIOISOTOPES ◽

10.3769/radioisotopes.44.275 ◽

1995 ◽

Vol 44 (4) ◽

pp. 275-279

Author(s):

Koichiro SERA

Keyword(s):

Ion Beam ◽

Ion Beam Analysis ◽

X Ray ◽

Beam Analysis

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Effect of Plasticizer of Sizing Agent on the Surface of Carbon Fibers and Interface of its Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.337.10 ◽

2011 ◽

Vol 337 ◽

pp. 10-15 ◽

Cited By ~ 1

Author(s):

Huan Xia Zhang ◽

Amin Cao ◽

Yong Kang Luo ◽

Li Wei

Keyword(s):

Contact Angle ◽

Carbon Fibers ◽

Photoelectron Spectroscopy ◽

Interfacial Shear Strength ◽

Dynamic Contact Angle ◽

Dynamic Contact ◽

Interfacial Shear ◽

X Ray ◽

Physical Changes ◽

Contact Angle Analysis

In this work, carbon fibers were sized with different plasticizer of sizing agent in order to improve the performances of carbon fibers and the interface of carbon fibers composites. The chemical and physical changes induced by the treatments on carbon fibers surface are examined using dynamic contact angle analysis test(DCAT) , X-ray photoelectron spectroscopy (XPS). The interfacial shear strength (IFSS) of CF/EP composites are analysised by micro-droplet test. At the same time, the wear resistance was also studied in order to understand the effect of the plasticizer of sizing agent on the carbon fibers. The study shows that the 3# sized carbon fiber has the better wetting and surface energy. XPS results reveal that the 3# samples show a significant increase in oxygen-containing groups, such as–C–OH, -COOH, -C–O–C- and -COOR. 3#sizing agent also show better interface adhesion between fibers and matrix and has better wear resistant properties.

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