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

MRS Advances ◽  
2019 ◽  
Vol 4 (41-42) ◽  
pp. 2249-2263
Author(s):  
Sukesh Ram ◽  
Amber A. Chow ◽  
Shaurya Khanna ◽  
Nikhil C. Suresh ◽  
Franscesca J. Ark ◽  
...  
Keyword(s):  
Surface Energy ◽  
Photoelectron Spectroscopy ◽  
Ion Beam ◽  
Surface Processing ◽  
X Ray ◽  
Native Oxides ◽  
Beam Analysis ◽  
Oxygen Coverage ◽  
Before And After ◽  
Contact Angle Analysis

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.

GaAs to Si Direct Wafer Bonding at T ≤ 220°C in Ambient Air via Nano-BondingTM and Surface Energy Engineering (SEE)

2021 ◽  
Author(s):  
Aashi R. Gurijala ◽  
Amber A. Chow ◽  
Shaurya Khanna ◽  
Nikhil C. Suresh ◽  
Pranav V. Penmatcha ◽  
...  
Keyword(s):  
Surface Energy ◽  
Wafer Bonding ◽  
Photoelectron Spectroscopy ◽  
Ion Beam ◽  
Ambient Air ◽  
Native Oxides ◽  
Direct Wafer Bonding ◽  
Beam Analysis ◽  
Modify Surface ◽  
Energy Engineering

Abstract When different semiconductors are integrated into hetero-junctions, native oxides generate interfacial defects and cause electronic recombination. Two state-of-the-art integration methods, hetero-epitaxy and Direct Wafer Bonding (DWB), require temperatures > 400°C to reduce native oxides. However, T > 400°C leads to defects due to lattice and thermal expansion mismatches. In this work, DWB temperatures are lowered via Nano-Bonding™ (NB) at T ≤ 220°C and P ≤ 60 kPa (9 psi). NB uses Surface Energy Engineering (SEE) at 300K to modify surface energies (γT) to far-from-equilibrium states, so cross-bonding occurs with little thermal activation and compression. SEE modifies γT and hydro-affinity (HA) via chemical etching, planarization, and termination that are optimized to yield 2-D Precursor Phases (2D-PP) metastable in ambient air and highly planar at the nano- and micro- scales. Complementary 2D-PPs nano-contact via carrier exchange from donor 2D-PP surfaces to acceptor ones. Here, NB models and SEE are applied to the DWB of GaAs to Si for photo-voltaics. SEE modifies (1) the initial γT0 and HA0 measured via Three Liquid Contact Angle Analysis, (2) the oxygen coverage measured via High Resolution Ion Beam Analysis, and (3) the oxidation states measured via X-Ray Photoelectron Spectroscopy. SEE etches hydrophobic GaAs oxides with γT = 33.4 ± 1 mJ/m2, and terminates GaAs (100) with H+, rendering GaAs hydrophilic with γT = 60 ± 2 mJ/m2. Similarly, hydrophilic Si native oxides are etched into hydrophobic SiO4H2. H+- GaAs nano-bonds reproducibly to Si, as measured via Surface Acoustic Wave Microscopy, validating the NB model and SEE design.

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

MRS Advances ◽  
2018 ◽  
Vol 3 (57-58) ◽  
pp. 3403-3411 ◽  
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.

Oxidation of Alloy-X in Subcritical, Transition, and Supercritical Water

CORROSION ◽  
10.5006/3881 ◽  
2021 ◽  
Author(s):  
Zachary Karmiol ◽  
Dev Chidambaram
Keyword(s):  
Supercritical Water ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Elevated Temperatures ◽  
Subcritical Water ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Based Superalloy ◽  
Before And After

This work investigates the oxidation of a nickel based superalloy, namely Alloy X, in water at elevated temperatures: subcritical water at 261°C and 27 MPa, the transition between subcritical and supercritical water at 374°C and 27 MPa, and supercritical water at 380°C and 27 MPa for 100 hours. The morphology of the sample surfaces were studied using scanning electron microscopy coupled with focused ion beam milling, and the surface chemistry was investigated using X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy before and after exposure studies. Surfaces of all samples were identified to comprise of a ferrite spinel containing aluminum.

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

MRS Advances ◽  
2018 ◽  
Vol 3 (57-58) ◽  
pp. 3379-3390 ◽  
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.

scholarly journals Synthesis of Novel Arginine-Based Flame Retardant and Its Application in Lyocell Fabric

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3588
Author(s):  
Jiayi Chen ◽  
Yansong Liu ◽  
Jiayue Zhang ◽  
Yuanlin Ren ◽  
Xiaohui Liu
Keyword(s):  
Fourier Transform ◽  
Heat Release ◽  
Flame Retardant ◽  
Photoelectron Spectroscopy ◽  
Fourier Transform Infrared ◽  
Ftir Analysis ◽  
Excellent Thermal Stability ◽  
X Ray ◽  
Cone Calorimeter Test ◽  
Before And After

Lyocell fabrics are widely applied in textiles, however, its high flammability increases the risk of fire. Therefore, to resolve the issue, a novel biomass-based flame retardant with phosphorus and nitrogen elements was designed and synthesized by the reaction of arginine with phosphoric acid and urea. It was then grafted onto the lyocell fabric by a dip-dry-cure technique to prepare durable flame-retardant lyocell fabric (FR-lyocell). X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated that the flame retardant was successfully introduced into the lyocell sample. Thermogravimetric (TG) and Raman analyses confirmed that the modified lyocell fabric featured excellent thermal stability and significantly increased char residue. Vertical combustion results indicated that FR-lyocell before and after washing formed a complete and dense char layer. Thermogravimetric Fourier-transform infrared (TG-FTIR) analysis suggested that incombustible substances (such as H2O and CO2) were produced and played a significant fire retarding role in the gas phase. The cone calorimeter test corroborated that the peak of heat release rate (PHRR) and total heat release (THR) declined by 89.4% and 56.4%, respectively. These results indicated that the flame retardancy of the lyocell fabric was observably ameliorated.

Characterization of Natural and Synthesized FeTiO3 Crystals With RBS/PIXE/XRD

1997 ◽  
Vol 07 (03n04) ◽  
pp. 265-275
Author(s):  
R. Q. Zhang ◽  
S. Yamamoto ◽  
Z. N. Dai ◽  
K. Narumi ◽  
A. Miyashita ◽  
...  
Keyword(s):  
Single Crystals ◽  
Ion Beam ◽  
Pressure Control ◽  
Floating Zone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Beam Analysis ◽  
Ppm Level

Natural FeTiO 3 (illuminate) and synthesized FeTiO 3, single crystals were characterized by Rutherford backscattering spectroscopy combined with channeling technique and particle-induced x-ray emission (RBS-C and PIXE). The results obtained by the ion beam analysis were supplemented by the x-ray diffraction analysis to identify the crystallographic phase. Oriented single crystals of synthesized FeTiO 3 were grown under the pressure control of CO 2 and H 2 mixture gas using a single-crystal floating zone technique. The crystal quality of synthesized FeTiO 3 single crystals could be improved by the thermal treatment but the exact pressure control is needed to avoid the precipitation of Fe 2 O 3 even during the annealing procedure. Natural FeTiO 3 contains several kinds of impurities such as Mn , Mg , Na and Si . The synthesized samples contain Al , Si and Na which are around 100 ppm level as impurities. The PBS-C results of the natural sample imply that Mn impurities occupy the Fe sublattice in FeTiO 3 or in mixed phase between ilmenite and hematite.

Chemical Structures of Native Oxides Formed During Wet Chemical Treatments on NH4F Treated Si(111) Surfaces

1992 ◽  
Vol 259 ◽  
Author(s):  
Takeo Hattori ◽  
Hiroki Ogawa
Keyword(s):  
Photoelectron Spectroscopy ◽  
Attenuated Total Reflection ◽  
Native Oxide ◽  
X Ray ◽  
Chemical Treatments ◽  
Chemical Structures ◽  
Native Oxides ◽  
Ft Ir ◽  
Wet Chemical ◽  
Silicon Interface

ABSTRACTChemical structures of native oxides formed during wet chemical treatments on NH4F treated Si(111) surfaces were investigated using X-ray Photoelectron Spectroscopy (XPS) and Fourier Transformed Infrared Attenuated Total Reflection(FT-IR-ATR). It was found that the amounts of Si-H bonds in native oxides and those at native oxide/silicon interface are negligibly small in the case of native oxides formed in H2SO4-H2O2-H2O solution. Based on this discovery, it was confirmed that native oxides can be characterized by the amount of Si-H bonds in native oxides. Furthermore, it was found that the combination of various wet chemical treatments with the treatment in NH4OH-H2O2-H2O solution results in the drastic decrease in the amount of Si-H bonds in native oxides.

scholarly journals A Novel Synthetic UV-Curable Fluorinated Siloxane Resin for Low Surface Energy Coating

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 979 ◽  
Author(s):  
Chunfang Zhu ◽  
Haitao Yang ◽  
Hongbo Liang ◽  
Zhengyue Wang ◽  
Jun Dong ◽  
...  
Keyword(s):  
Surface Energy ◽  
Photoelectron Spectroscopy ◽  
Contact Angles ◽  
Proton Nuclear Magnetic Resonance ◽  
Energy Materials ◽  
Uv Curable ◽  
X Ray ◽  
Low Surface Energy ◽  
Low Concentrations ◽  
Siloxane Polymers

Low surface energy materials have attracted much attention due to their properties and various applications. In this work, we synthesized and characterized a series of ultraviolet (UV)-curable fluorinated siloxane polymers with various fluorinated acrylates—hexafluorobutyl acrylate, dodecafluoroheptyl acrylate, and trifluorooctyl methacrylate—grafted onto a hydrogen-containing poly(dimethylsiloxane) backbone. The structures of the fluorinated siloxane polymers were measured and confirmed by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. Then the polymers were used as surface modifiers of UV-curable commercial polyurethane (DR-U356) at different concentrations (1, 2, 3, 4, 5, and 10 wt %). Among three formulations of these fluorinated siloxane polymers modified with DR-U356, hydrophobic states (91°, 92°, and 98°) were obtained at low concentrations (1 wt %). The DR-U356 resin is only in the hydrophilic state at 59.41°. The fluorine and siloxane element contents were investigated by X-ray photoelectron spectroscopy and the results indicated that the fluorinated and siloxane elements were liable to migrate to the surface of resins. The results of the friction recovering assays showed that the recorded contact angles of the series of fluorinated siloxane resins were higher than the original values after the friction-annealing progressing.

Sign in / Sign up

Export Citation Format

Share Document