Surface Protection during Plasma Hydrogenation for Acceptor Passivation in InP

1989 ◽  
Vol 163 ◽  
Author(s):  
J. Lopata ◽  
W. C. Dautremont-Smith ◽  
S. J. Pearton ◽  
J. W. Lee ◽  
N. T. Ha ◽  
...  
Keyword(s):  
Depth Profiling ◽  
Protective Layer ◽  
Coated Sample ◽  
Dielectric Films ◽  
Wafer Surface ◽  
Plasma Exposure ◽  
Surface Protection ◽  
P Loss ◽  
Inp Substrate ◽  
Sputter Deposited

AbstractVarious dielectric and metallic films were examined as H-permeable surface protection layers on InP during H2 or D2 plasma exposure for passivation of acceptors in the InP. Plasma deposited SiNx, SiO2, and a-Si(H) films ranging in thickness from 85 to 225 Å were used to protect p-InP during D2 plasma exposure at 250°C. Optimum protective layer thicknesses were determined by a trade-off between the effectiveness of the layer to prevent P loss from the wafer surface and the ability to diffuse atomic H or D at a rate greater than or equal to that in the underlying InP. SIMS and capacitance-voltage depth profiling were used to determine the extent of D in-diffusion and acceptor passivation respectively. Sputter deposited W and e-beam evaporated Ti films ~100 Å thick were also evaluated. The W coated sample yielded similar results to those with dielectric films in that acceptors in p-InP were passivated to a similar depth for the same plasma exposure. The 100 Å Ti film, however, did not allow the D to diffuse into the InP substrate. It is surmised that the Ti film trapped the D, thus preventing diffusion into the substrate.

In-Situ, Time Resolved, Kinetics of Reactions in Co-Ge thin Films

1991 ◽  
Vol 237 ◽  
Author(s):  
R. M. Walser ◽  
Byung-Hak Lee ◽  
Alaka Valanju ◽  
Winston Win ◽  
M. F. Becker
Keyword(s):  
Depth Profiling ◽  
Laser Interferometry ◽  
Semiconductor Interface ◽  
Time Resolved ◽  
Interface Reactions ◽  
Valuable Adjunct ◽  
Diffusion Controlled ◽  
Sputter Deposited ◽  
Time Required

ABSTRACTWe report the first kinetic study of metal-semiconductor interface reactions using in-situ, time resolved, laser interferometry. Diffusion couples with Co/Ge thicknesses of 1500 Å/1500 Å were sputter deposited on silicon wafers, and vacuum-annealed at temperatures between 300°C-400°C. Under these conditions polycrystalline CoGe was expected to form [1]. Real time laser (HeNe 6328 Å) interferograms for each anneal were recorded in-situ. These data were supplemented by information from AES and X-ray.For temperatures below 400°C the diffusion controlled formation of CoGe was observed. The composition was confirmed by Auger depth profiling that showed uniform Co and Ge concentrations when the reaction went to completion. The well defined interferences fringes were formed by the dissolution of amorphous Ge. The activation energy = 1.6 eV for the formation of CoGe were determined with precision from the temperature dependence of the time required to anneal the fixed λ/4 distance between adjacent minima and maxima of the interferogram. We discuss the evidence for formation of an intermediate Co-rich compound following the initial diffusion of Co into Ge. The results of these experiments indicate that optical interferometry will be a valuable adjunct to other techniques used to study metal-semiconductor interface reactions.

scholarly journals An overview on the non-destructive in-depth surface analysis of corrosion-resistant films: A case study of W-xCr deposits in 12 M HCl solution

BIBECHANA ◽  
2021 ◽  
Vol 18 (1) ◽  
pp. 201-213
Author(s):  
Jagadish Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Depth Profiling ◽  
Surface Films ◽  
High Corrosion Resistance ◽  
Corrosion Rates ◽  
High Corrosion ◽  
Depth Analysis ◽  
Sputter Deposited ◽  
Non Destructive ◽  
Hcl Solution

Non-destructive in-depth analysis of the surface films formed on the sputter-deposited binary W-xCr (x = 25, 57, 91 at %) alloys in 12 M HCl solution open to air at 30 °C was investigated using an angle-resolved X-ray photoelectron spectroscopic (AR-XPS) technique to understand the synergistic corrosion resistance effects of showing very low corrosion rates, even lower than both alloying metals of the deposits. The average corrosion rates of these three tungsten-based sputter deposits found to be more than five orders of magnitude (between 3.1 × 10−3 and 7.2 × 10−3 mm/y) to that of chromium and also nearly one order of magnitude lower than that of tungsten metals. Such high corrosion resistance of the sputter-deposited W-xCr alloys is due to the formation of homogeneous passive double oxyhydroxide film consisting of Wox and Cr4+ cations without any concentration gradient in-depth after immersion in 12 M HCl solution open to air at 30 °C from the study of the non-destructive depth profiling technique of AR-XPS. Consequently, both alloying elements of tungsten and niobium are acted synergistically in enhancing high corrosion resistance properties of the alloys in such aggressive electrolyte. BIBECHANA 18 (2021) 201-213

Abstract: Silicon Device Surface Protection With Dielectric Films and Coatings

1973 ◽  
Vol 10 (1) ◽  
pp. 284-284
Author(s):  
J. R. Szedon ◽  
T. A. Temofonte ◽  
J. A. Jackson ◽  
D. C. Philips
Keyword(s):  
Dielectric Films ◽  
Surface Protection ◽  
Silicon Device

Sol-Gel Protective Films for Metal Solar Mirrors

1988 ◽  
Vol 121 ◽  
Author(s):  
Scott Reed ◽  
Carol Ashley
Keyword(s):  
Protective Coatings ◽  
Sol Gel ◽  
Protective Layer ◽  
Front Surface ◽  
Optical Measurements ◽  
Preliminary Evaluation ◽  
Environmental Testing ◽  
Specular Reflectance ◽  
Outdoor Environments ◽  
Sputter Deposited

ABSTRACTFront-surface metal mirrors were coated with a variety of sol-gel derived glass films for preliminary evaluation as protective coatings for silver. Optical measurements (hemispherical, diffuse and specular reflectance) were used to characterize changes in the mirror resulting from the application of the sol, subsequent processing, or environmental testing. The abrasion resistance of the films was determined on sol-gel coated silicon wafers per ASTM procedures. The mirrors were exposed to outdoor environments in Albuquerque, N.M., as well as accelerated testing in H2SO4, with periodic monitoring of optical properties. A two layer coating scheme, consisting of a thin primary protective layer of sputter deposited SiO2 followed by a thicker sol-gel overcoat, was also evaluated.

Depth Profiling in Thin Dielectric Films

1991 ◽  
Vol 22 (1-2) ◽  
pp. 455-470 ◽  
Author(s):  
P. W. Bohn ◽  
D. R. Miller
Keyword(s):  
Depth Profiling ◽  
Dielectric Films ◽  
Thin Dielectric Films

Depth Profiling Biaxial Stresses in Sputter Deposited Molybdenum Films; Use of the Cos2ϕ Method

1997 ◽  
pp. 363-370 ◽  
Author(s):  
B. L. Ballard ◽  
P. K. Predecki ◽  
T. R. Watkins ◽  
K. J. Kozaczek ◽  
D. N. Braski ◽  
...  
Keyword(s):  
Depth Profiling ◽  
Sputter Deposited

Interfacial Reactions of Refractory Metals Niobium and Tantalum with Ceramics Silicon Carbide and Alumina

1989 ◽  
Vol 170 ◽  
Author(s):  
A. Joshl ◽  
H. S. Hu ◽  
J. Wadsworth
Keyword(s):  
Silicon Carbide ◽  
Ternary Phase ◽  
Depth Profiling ◽  
Interfacial Reactions ◽  
Matrix Composites ◽  
Sapphire Substrates ◽  
Polycrystalline Silicon Carbide ◽  
Sputter Deposited ◽  
Strength And Ductility ◽  
Made In

AbstractRecent interest in the development of advanced metal matrix composites has prompted research on interfacial reactions of Nb and Ta with candidate reinforcements such as silicon carbide and alumina. Formation of reaction layers as small as 0.1 μm can be detrimental to composite strength and ductility and in some instances to the corrosion behavior, which suggests the importance of understanding the early stages of interfacial reactions. Thin films of Nb and Ta were sputter deposited on single crystal and polycrystalline silicon carbide and on sapphire substrates, and the nature and extent of reaction evahiated using Auger depth profiling and electron microscopy. In the Nb/SiC system, NbCX is the first reaction product to form, but the overall extent of the reaction is dominated by the formation of the more stable NbCXSiY ternary phase. Little or no interfacial reaction was observed in the Nb/Al2O3 system for up to 4 hburs at 1100°C, which also suggests that Al2O3 may be a potential diffusion barrier to minimize reactions in the Nb/SiC system. Similar interesting observations were made in the Ta/SiC and Ta/Al2O3 systems.

scholarly journals Evaluation of corrosion resistance of powder coatings after various surface chemical pre-treatment

2017 ◽  
Vol 61 (2) ◽  
pp. 80-85
Author(s):  
D. Draganovská ◽  
J. Brezinová
Keyword(s):  
Corrosion Resistance ◽  
Protective Layer ◽  
Powder Coating ◽  
Conversion Coating ◽  
Powder Coatings ◽  
Surface Protection ◽  
Pre Treatment ◽  
Respective Surface ◽  
System Selection

Abstract The surface treatment by a powder coating is one of the progressive technologies. Such coatings are resistant to corrosion and mechanical wearing. The quality of surface protection is affected primarily by a layer pre-treatment, the type of surface tretment, the system selection and the method and quality of application. Taking into account all the surface pre-tretment methods, the chemical pre-modification is a leading method. One of the methods is pre-treatment using a conversion coating which was developed on the nanotechnology basis - BONDRITE NT. That non-phosphate chemical pre-treatment is utilized at a surrounding temperature. It creates nano-ceramic protective layer on steel, zinc and aluminium surfaces, and as the result the coating has a significant adhesion. In the paper, the possibilities for the improvement of corrosion resistance of powder coatings using the subject conversion coating are presented at the current pasivation of respective surface.

scholarly journals Coherent Transport in Nb/δ-Doped-GaAs Hybrid Microstructures

2003 ◽  
Vol 17 (18) ◽  
pp. 955-971 ◽  
Author(s):  
F. Giazotto ◽  
P. Pingue ◽  
F. Beltram
Keyword(s):  
Matrix Theory ◽  
Protective Layer ◽  
Ex Situ ◽  
Interference Effects ◽  
Coherent Transport ◽  
Fabrication Procedure ◽  
Sputter Deposited ◽  
The Impact ◽  
Complex Semiconductor

Coherent transport in Nb/GaAs superconductor-semiconductor microstructures is presented. The structure fabrication procedure is based on δ-doped layers grown by molecular-beam-epitaxy near the GaAs surface, followed by an As cap layer to protect the active semiconductor layers during ex situ transfer. The superconductor is then sputter deposited in situ after thermal desorption of the protective layer. Two types of structures in particular will be discussed, i.e. a reference junction and the engineered one that contains an additional insulating AlGaAs barrier inserted during the growth in the semiconductor. This latter configuration may give rise to controlled interference effects and realizes the model introduced by de Gennes and Saint-James in 1963. While both structures show reflectionless tunneling-dominated transport, only the engineered junction shows additionally a low-temperature single marked resonance peaks superimposed to the characteristic Andreev-dominated subgap conductance. The analysis of coherent magnetotransport in both microstructures is successfully performed within the random matrix theory of Andreev transport and ballistic effects are included by directly solving the Bogoliubov–de Gennes equations. The impact of junction morphology on reflectionless tunneling and the application of the employed fabrication technique to the realization of complex semiconductor-superconductor systems are also discussed.

Laser treatment of high strength low alloy steel and electrochemical response of the surface

2015 ◽  
Vol 67 (2) ◽  
pp. 166-171 ◽  
Author(s):  
B. S. Yilbas ◽  
Ihsan-ul-Haq Toor ◽  
Jahanzaib Malik ◽  
F. Patel
Keyword(s):  
Corrosion Resistance ◽  
Laser Treatment ◽  
Hsla Steel ◽  
Protective Layer ◽  
High Strength ◽  
Content Type ◽  
Surface Protection ◽  
Corrosive Environments ◽  
Insight Into ◽  
Treated Layer

Purpose – The purpose of the present study is to report the results of the laser treatment of high-strength low-alloy (HSLA) steel surface and corrosion response of the treated surface that was carried out. Metallurgical and morphological changes in the laser-treated layer are also examined. Laser treatment of the alloy surface improves the surface properties; however, development of high thermal stress field in the treated layer can exceed the yielding limit of the alloy lowers, particularly, the corrosion resistance of the resulting surface. Design/methodology/approach – Pre-prepared workpiece surfaces are laser-treated and electrochemically tested in an electrolytic solution. Corrosion rate of the resulting surface is analyzed and pit sites are examined. Findings – It is found that the presence of nitride compounds and fine grains acts like as a self-protective layer at the laser-treated surface while lowering the corrosion resistance. Consequently, laser gas-assisted treatment provides a positive effect on the corrosion properties of the treated surface through lowering the corrosion current. The pits are shallow and do not form a regular pattern at the workpiece surface. The secondary pitting is prevented by the protective layer formed at the laser-treated surface. Research limitations/implications – The study can be extended to include laser treatment including the hard particles, such as carbides, at the surface. However, this extension is left to another study. Practical implications – Laser treatment can be used for protection of surfaces from wear and corrosive environments. The findings of this study give insight into the improvement of the surface characteristics for this purpose. It serves to industry for the practical solution of the surface protection from corrosive environments. Social implications – The researchers and scientists working in the area get the benefit from the outcome of this work. Originality/value – It is an original work and gives insight into the enhancement of the corrosion resistance of HSLA steel after the laser treatment process.

Sign in / Sign up

Export Citation Format

Share Document