X-Ray Photoemission Study of Silicon Nitride-GaAs Interfaces in Relation with GaAs Mesfet Passivation

1987 ◽  
Vol 98 ◽  
Author(s):  
Patrick Alnot ◽  
J. Olivier ◽  
F. Wyczisk ◽  
J. F. Peray ◽  
R. Joubart
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Excitation Frequency ◽  
Chemical Vapor ◽  
Gaas Surface ◽  
Surface Pretreatment ◽  
X Ray ◽  
Chemical Vapor Deposited ◽  
Plasma Excitation ◽  
Photoemission Study

ABSTRACTWe have studied the influence of different GaAs surface treatments on the chemical composition and electrical behavior of the Si 3 N4 -GaAs interface, where Si 3 N4 was plasma enhanced chemical vapor deposited (PECVD) onto the treated GaAs(100) substrate. The chemistry of the resulting interface has been studied by X-ray photoelectron spectroscopy (XPS). It has been demonstrated that the chemical composition of the Si 3 N4-GaAs interface is drastically dependent on GaAs surface pretreatment and r.f. plasma excitation frequency. Output-input powers characteristics have been measured on chemically treated planar MESFET after Si3N4. passivation.

scholarly journals Characterization and Applications of Nanoparticles Modified in-Flight with Silica or Silica-Organic Coatings

Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 530 ◽  
Author(s):  
Patrick Post ◽  
Lisa Wurlitzer ◽  
Wolfgang Maus-Friedrichs ◽  
Alfred Weber
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Elevated Temperatures ◽  
Chemical Vapor ◽  
Organic Coatings ◽  
Coated Particles ◽  
X Ray ◽  
Transmission Electron ◽  
Coating Composition ◽  
Modification Of The Surface

Nanoparticles are coated in-flight with a plasma-enhanced chemical vapor deposition (PECVD) process at ambient or elevated temperatures (up to 300 °C). Two silicon precursors, tetraethyl orthosilicate (TEOS) and hexamethyldisiloxane (HMDSO), are used to produce inorganic silica or silica-organic shells on Pt, Au and TiO2 particles. The morphology of the coated particles is examined with transmission electron microscopy (TEM) and the chemical composition is studied with Fourier-transform infrared spectroscopy (FTIR), Energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). It is found that both the precursor and certain core materials have an influence on the coating composition, while other parameters, such as the precursor concentration, aerosol residence time and temperature, influence the morphology, but hardly the chemical composition. The coated particles are used to demonstrate simple applications, such as the modification of the surface wettability of powders and the improvement or hampering of the photocatalytic activity of titania particles.

Improvement in the Activation Efficiency of Implanted Si in GaAs using Oxygen Plasma Pretreatment

1992 ◽  
Vol 259 ◽  
Author(s):  
Jaeshin Cho ◽  
Leszek M. Pawlowicz ◽  
Naresh C. Saha
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxygen Plasma ◽  
Chemical Vapor ◽  
Gaas Surface ◽  
Oxygen Plasma Treatment ◽  
Surface Conditions ◽  
X Ray ◽  
Plasma Pretreatment ◽  
Activation Efficiency ◽  
Thick Oxide Layer

ABSTRACTWe have investigated the effect of GaAs surface conditions prior to plasma enhanced chemical vapor deposition of a silicon nitride cap on the activation efficiency of implanted Si in GaAs. The oxygen plasma treatment improved the activation efficiency of implanted Si by ∼35% over (1:10) NH4OH:H2O treatment. X-ray photoelectron spectroscopy (XPS) analysis of the oxygen plasma treated GaAs surface indicated the formation of ∼25Å thick oxide layer consisting of Ga2O3, As2O3, As2O5 and elemental As. During the activation anneal, the arsenic-containing oxides react with the GaAs substrate to form Ga2O3 and elemental As. The presence of excess As between the GaAs and the nitride cap film increases the probability that the implanted Si incorporates in the Ga sites over the As sites, and thereby improves the activation efficiency. This surface-related mechanism suggests that the variation in activation efficiency is mostly attributed to variation in surface conditions, and may explain the wide variety of reported values of activation efficiency.

scholarly journals The Structure and Chemical Composition of the Cr and Fe Pyrolytic Coatings on the MWCNTs’ Surface According to NEXAFS and XPS Spectroscopy

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 374 ◽  
Author(s):  
Danil Sivkov ◽  
Olga Petrova ◽  
Alena Mingaleva ◽  
Anatoly Ob’edkov ◽  
Boris Kaverin ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Diffraction Order ◽  
Charge Compensation ◽  
Organic Chemical ◽  
Total Electron ◽  
X Ray ◽  
Metal Atoms ◽  
Mwcnts Surface

The paper is devoted to the structure and properties of the composite material based on multi-walled carbon nanotubes (MWCNTs) covered with pyrolytic iron and chromium. Fe/MWCNTs and Cr/MWCNTs nanocomposites have been prepared by the metal organic chemical vapor deposition (MOCVD) growth technique using iron pentacarbonyl and bis(arene)chromium compounds, respectively. Composites structures and morphologies preliminary study were performed using X-ray diffraction, scanning and transmission electron microscopy and Raman scattering. The atomic and chemical composition of the MWCNTs’ surface, Fe-coating and Cr-coating and interface—(MWCNTs surface)/(metal coating) were studied by total electron yield method in the region of near-edge X-ray absorption fine structure (NEXAFS) C1s, Fe2p and Cr2p absorption edges using synchrotron radiation of the Russian-German dipole beamline (RGBL) at BESSY-II and the X-ray photoelectron spectroscopy (XPS) method using the ESCALAB 250 Xi spectrometer and charge compensation system. The absorption cross sections in the NEXAFS C1s edge of the nanocomposites and MWCNTs were measured using the developed approach of suppressing and estimating the contributions of the non-monochromatic background and multiple reflection orders radiation from the diffraction grating. The efficiency of the method was demonstrated by the example of the Cr/MWCNT nanocomposite, since its Cr2p NEXAFS spectra contain additional C1s NEXAFS in the second diffraction order. The study has shown that the MWCNTs’ top layers in composite have no significant destruction; the MWCNTs’ metal coatings are continuous and consist of Fe3O4 and Cr2O3. It is shown that the interface between the MWCNTs and pyrolytic Fe and Cr coatings has a multilayer structure: a layer in which carbon atoms along with epoxy –C–O–C– bonds form bonds with oxygen and metal atoms from the coating layer is formed on the outer surface of the MWCNT, a monolayer of metal carbide above it and an oxide layer on top. The iron oxide and chromium oxide adhesion is provided by single, double and epoxy chemical binding formation between carbon atoms of the MWCNT top layer and the oxygen atoms of the coating, as well as the formation of bonds with metal atoms.

scholarly journals Effect of Cellulose Nanocrystals on the Coating of Chitosan Nanocomposite Film Using Plasma-Mediated Deposition of Amorphous Hydrogenated Carbon (a–C:H) Layers

2020 ◽  
Vol 6 (3) ◽  
pp. 51 ◽  
Author(s):  
Torben Schlebrowski ◽  
Zineb Kassab ◽  
Mounir El Achaby ◽  
Stefan Wehner ◽  
Christian B. Fischer
Keyword(s):  
Chemical Composition ◽  
Cellulose Nanocrystals ◽  
Photoelectron Spectroscopy ◽  
Nanocomposite Film ◽  
Chemical Vapor ◽  
Good Alternative ◽  
Ex Situ ◽  
X Ray ◽  
Wide Range ◽  
Amorphous Hydrogenated Carbon

The substitution of petroleum-based polymers with naturally derived biopolymers may be a good alternative for the conservation of natural fossil resources and the alleviation of pollution and waste disposal problems. However, in order to be used in a wide range of applications, some biopolymers’ properties should be enhanced. In this study, biocompatible, non-toxic, and biodegradable chitosan (CS) film and CS reinforced with 10 wt% of cellulose nanocrystals (CN–CS) were coated with amorphous hydrogenated carbon layers (a–C:H) of different thickness. To investigate the effect of the nano-reinforcement on the a–C:H layer applied, mild radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) was used to coat the CS and its CN–CS bio-nanocomposite film. Both the surface characteristics and the chemical composition were analyzed. The surface morphology and wettability were examined by ex-situ atomic force microscopy (AFM) and contact angle measurements (CA), respectively. Hereby, the relationship between sp2/sp3 ratios on a macroscopic scale was also evaluated. For the investigation of the chemical composition, the surface sensitive synchrotron X-ray radiation techniques near edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS) as well as diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) were used.

Surface Modification of Chemical Vapor Deposited Diamond Induced by Power Ultrasound: An X-Ray Photoelectron Spectroscopy Study

2001 ◽  
Vol 4 (7) ◽  
pp. E29 ◽  
Author(s):  
Christiaan H. Goeting ◽  
Frank Marken ◽  
Anthony R. Osborn ◽  
Richard G. Compton ◽  
John S. Foord
Keyword(s):  
Surface Modification ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Spectroscopy Study ◽  
Power Ultrasound ◽  
X Ray ◽  
Chemical Vapor Deposited

Chemical Stability of Reactively Sputtered AlN with Plasma Enhanced Chemical Vapor Deposited SiO2 and SiNx

1994 ◽  
Vol 343 ◽  
Author(s):  
Jaeshin Cho ◽  
Naresh C. Saha
Keyword(s):  
Chemical Stability ◽  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Etch Rate ◽  
Auger Electron ◽  
Chemical Vapor ◽  
Nitride Film ◽  
X Ray ◽  
Chemical Vapor Deposited ◽  
Wet Etch

ABSTRACTWe have studied the chemical stability of reactively sputtered aluminum nitride film with plasma-enhanced chemical vapor deposited SiO2 and SiNx films. It was found that the PECVD SiO2 film reacted with A1N to form aluminosilicate (3Al2O3·2SiO2) at the SiO2/A1N interface after annealing above 550°C. The presence of Al-0 bonds at the SiO2/AlN interface was verified with x-ray photoelectron spectroscopy and x-ray induced Auger electron spectroscopy. The formation of aluminosilicate resulted in significant decrease in the wet etch rate of A1N layer. For SiNx/AlN/Si layered structure, no interfacial reactions were detected at the SiNx/AlN interface after annealing up to 850°C. These results confirm the thermodynamic predictions on the mutual stability of SiNx/AlN and SiO2/AlN.

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