scholarly journals Laser-Induced Backside Wet Etching of Transparent Materials with Organic and Metallic Absorbers

2008 ◽  
Vol 2008 ◽  
pp. 1-13 ◽  
Author(s):  
K. Zimmer ◽  
R. Böhme
Keyword(s):  
Periodic Structures ◽  
Pulse Length ◽  
Surface Region ◽  
Fused Silica ◽  
Wet Etching ◽  
Near Surface ◽  
Transparent Materials ◽  
Etched Surface ◽  
The Impact ◽  
Selection Of

Laser-induced backside wet etching (LIBWE) allows the high-quality etching of transparent materials for micro- and nanopatterning. Recent own results of LIBWE with hydrocarbon and metallic absorbers (H- and M-LIBWE) are summarized and compared with selected results of other groups regarding the etching process and the etched surface. Significant results on the impact of the liquid absorber, the material and the wavelength, and the pulse length of the laser to the etching are selected for this comparison. The etching of submicron-sized periodic structures in sapphire and fused silica with interference techniques and the selection of the preferred method in dependence on the material and the processing goal discussed. The experimental results are discussed on a thermal model considering both interface and volume absorption of the laser beam. These results have the conclusion that the etching at M-LIBWE is mainly due to material melting and evaporation whereas at H-LIBWE, a modified near-surface region with a very high absorption is ablated.

scholarly journals Decadal regional air quality simulations over Europe in present climate: near surface ozone sensitivity to external meteorological forcing

2010 ◽  
Vol 10 (23) ◽  
pp. 11805-11821 ◽  
Author(s):  
E. Katragkou ◽  
P. Zanis ◽  
I. Tegoulias ◽  
D. Melas ◽  
I. Kioutsioukis ◽  
...  
Keyword(s):  
Air Quality ◽  
Solar Radiation ◽  
Boundary Conditions ◽  
Surface Ozone ◽  
Regional Climate ◽  
Radiation Temperature ◽  
Meteorological Forcing ◽  
Near Surface ◽  
The Impact ◽  
Selection Of

Abstract. Regional climate-air quality decadal simulations over Europe were carried out with the RegCM3/CAMx modeling system for the time slice 1991–2000, in order to study the impact of different meteorological forcing on surface ozone. The RegCM3 regional climate model was firstly constrained by the ERA40 reanalysis dataset which is considered as an experiment with perfect meteorological boundary conditions and then it was constrained by the global circulation model ECHAM5. A number of meteorological parameters were examined including the 500 mb geopotential height, solar radiation, temperature, cloud liquid water path, planetary boundary layer height and surface wind. The different RegCM meteorological forcing resulted in changes of near surface ozone over Europe ranging between ± 4 ppb for winter and summer. The area showing the greatest sensitivity in O3 during winter is central and southern Europe while in summer central north continental Europe. The different meteorological forcing impacts on the atmospheric circulation, which in turn affects cloudiness and solar radiation, temperature, wind patterns and the meteorology depended biogenic emissions. For comparison reasons, the impact of chemical boundary conditions on surface ozone was additionally examined with a series of sensitivity studies, indicating that surface ozone changes are comparable to those caused by the different meteorological forcing. These findings suggest that, when it comes to regional climate-air quality simulations, the selection of external meteorological forcing can be as important as the selection of adequate chemical lateral boundary conditions.

Comparison of Chlorine Based In Situ Etching of 4H SiC Substrates

2007 ◽  
Vol 556-557 ◽  
pp. 69-72
Author(s):  
Mike F. MacMillan ◽  
Mark J. Loboda ◽  
Jian Wei Wan ◽  
Gil Yong Chung ◽  
E.P. Carlson ◽  
...  
Keyword(s):  
Gas Phase ◽  
Buffer Layer ◽  
Epitaxial Layer ◽  
Wafer Surface ◽  
Epitaxial Deposition ◽  
Silicon Vapor ◽  
Etched Surface ◽  
The Impact ◽  
Selection Of

Gas phase etching of 4H SiC n+ substrates was performed utilizing chlorine containing etch chemistries in a hot wall CVD system. Carbon and silicon vapor were added to explore selective etching reactions on the wafer surface. The impact of the etch on the bare wafer surface as a function of temperature and etch chemistry is investigated. Selection of the etch chemistry and temperature are critical to ensure a smooth etched surface on which to begin epitaxial deposition. Etching also influences defect propagation from the substrate into the epitaxial layer. The results show etch chemistry reactions will influence the conversion of micropipes in the epi buffer layer.

Surface Conversion Effects in Plasma-Damaged p-GaN

1999 ◽  
Vol 595 ◽  
Author(s):  
X.A. Cao ◽  
S.J. Pearton ◽  
G.T. Dang ◽  
A.P. Zhang ◽  
F. Ren ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Thermal Annealing ◽  
Surface Region ◽  
High Density ◽  
Wet Etching ◽  
Ion Fluxes ◽  
Type Conversion ◽  
Near Surface ◽  
Ion Energies ◽  
Surface Conversion

AbstractThe near-surface (400-500Å) of p-GaN exposed to high density plasmas is found to become more compensated through the introduction of shallow donors. At high ion fluxes or ion energies there can be type-conversion of this surface region. Two different methods for removal of the damaged surface were investigated; wet etching in KOH, which produced self-limiting etch depths or thermal annealing under N2 which largely restored the initial electrical properties.

Consequences of Hot Rolling of Recycled AA5050 on Filiform Corrosion

2006 ◽  
Vol 519-521 ◽  
pp. 687-692 ◽  
Author(s):  
P. Premendra ◽  
W. Loven ◽  
H. Terryn ◽  
J.H.W. de Wit ◽  
Laurens Katgerman
Keyword(s):  
Hot Rolling ◽  
Corrosion Behaviour ◽  
Surface Region ◽  
Surface Activation ◽  
Metal Production ◽  
Near Surface ◽  
Filiform Corrosion ◽  
Hot And Cold Rolling ◽  
The Impact ◽  
Effect Of Surface

The presence of a heavily deformed and corrosion susceptible surface/near-surface region on rolled aluminium alloy has been amongst the most important problems which the aluminium manufacturers are dealing with. While primarily the composition of the alloying elements and the thermo-mechanical treatment play an important role in determining surface activation, the importance of several other secondary parameters cannot be ignored. This paper tries to identify the impact of several factors, associated with sheet metal production, on the corrosion behaviour e.g. (a) type of the cast bar fed into the hot rolling mill, whether scalped or not scalped, (b) importance of homogenisation and in-line heat treatment, in relation to pre-existing understanding of surface activation on AA3005, (c) effect of hot and cold rolling (d) effect of surface finish, etc. The alloy under investigation was recycled AA5050, containing high Fe and Si as impurities, and used commercially for architectural purpose, eg. window facades.

POSSIBLE CONNECTION BETWEEN THE SEISMIC SHOCKS AND THE IMPACT OF SOLAR WIND ON THE LITHOSPHERE (LOCAL CASES)

2021 ◽  
Vol 43 (1) ◽  
pp. 29-40
Author(s):  
Dmitriy GONSIROVSKYI
Keyword(s):  
Solar Wind ◽  
Surface Region ◽  
Solar Wind Plasma ◽  
Magnetic Clouds ◽  
Solar Wind Parameter ◽  
Tectonic Structures ◽  
Additional Energy ◽  
Near Surface ◽  
Parameter Values ◽  
The Impact

Disruptions of unstable equilibrium in the corresponding tectonic structures causing the onset of earthquakes are put in relation to Sun spot flares and coronal mass ejections. They generate magnetic clouds of solar wind plasma moving at much higher speed than the constant background to the Earth. The author assumes that additional energy is introduced to shallow earthquake foci due to the action of breakthrough injections into the Earth’s near-surface region of plasma clumps of geoeffective solar wind components disconnected into the magnetosphere. As a research tool, we used the method of graphical correlation between bursts of geoeffective solar wind parameter values and the occurrence of subsequent starts and repetitions of earthquake shocks. The examples given for Europe, South Asia, the Indian and Pacific oceans coasts consistently confirm the validity of the author's analytical understanding of the earthquake shocks beginning as a result of the destruction of the subsurface by injections of solar wind plasma clots in earthquake-prone zones. The problem under study is considered to be relevant in connection with the implementation of targeted forecast work. In the General scientific plan, consideration of the influence of solar-meter origins of factors are proposed to be included in the programs of studying earthquakes as one of their items. The obtained results should serve as a dynamic addition to the information placed on the maps of seismic zoning.

scholarly journals Surface Conversion Effects in Plasma-Damaged p-GaN

2000 ◽  
Vol 5 (S1) ◽  
pp. 558-569 ◽  
Author(s):  
X.A. Cao ◽  
S.J. Pearton ◽  
G.T. Dang ◽  
A.P. Zhang ◽  
F. Ren ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Thermal Annealing ◽  
Surface Region ◽  
High Density ◽  
Wet Etching ◽  
Ion Fluxes ◽  
Type Conversion ◽  
Near Surface ◽  
Ion Energies ◽  
Surface Conversion

The near-surface (400-500Å) of p-GaN exposed to high density plasmas is found to become more compensated through the introduction of shallow donors. At high ion fluxes or ion energies there can be type-conversion of this surface region. Two different methods for removal of the damaged surface were investigated; wet etching in KOH, which produced self-limiting etch depths or thermal annealing under N2 which largely restored the initial electrical properties.

Preparation of cross-sectional samples for near-surface TEM studies

1987 ◽  
Vol 45 ◽  
pp. 380-381
Author(s):  
R.C. Dickenson ◽  
K.R. Lawless
Keyword(s):  
Standard Sample ◽  
Surface Region ◽  
Specimen Preparation ◽  
Thick Sheet ◽  
Drill Bit ◽  
Sample Holder ◽  
Metal Interface ◽  
Cross Sectional ◽  
Near Surface ◽  
Cold Worked

In thermal oxidation studies, the structure of the oxide-metal interface and the near-surface region is of great importance. A technique has been developed for constructing cross-sectional samples of oxidized aluminum alloys, which reveal these regions. The specimen preparation procedure is as follows: An ultra-sonic drill is used to cut a 3mm diameter disc from a 1.0mm thick sheet of the material. The disc is mounted on a brass block with low-melting wax, and a 1.0mm hole is drilled in the disc using a #60 drill bit. The drill is positioned so that the edge of the hole is tangent to the center of the disc (Fig. 1) . The disc is removed from the mount and cleaned with acetone to remove any traces of wax. To remove the cold-worked layer from the surface of the hole, the disc is placed in a standard sample holder for a Tenupol electropolisher so that the hole is in the center of the area to be polished.

The Effects of Ion Implantation on the Surface Features of Inconel 600

1985 ◽  
Vol 43 ◽  
pp. 288-289
Author(s):  
John D. Rubio
Keyword(s):  
Grain Boundary ◽  
Ion Implantation ◽  
Nuclear Power ◽  
Power Plants ◽  
Surface Region ◽  
Selective Dissolution ◽  
Boundary Region ◽  
Near Surface ◽  
Inconel 600 ◽  
Steam Generator Tubing

The degradation of steam generator tubing at nuclear power plants has become an important problem for the electric utilities generating nuclear power. The material used for the tubing, Inconel 600, has been found to be succeptible to intergranular attack (IGA). IGA is the selective dissolution of material along its grain boundaries. The author believes that the sensitivity of Inconel 600 to IGA can be minimized by homogenizing the near-surface region using ion implantation. The collisions between the implanted ions and the atoms in the grain boundary region would displace the atoms and thus effectively smear the grain boundary.To determine the validity of this hypothesis, an Inconel 600 sample was implanted with 100kV N2+ ions to a dose of 1x1016 ions/cm2 and electrolytically etched in a 5% Nital solution at 5V for 20 seconds. The etched sample was then examined using a JEOL JSM25S scanning electron microscope.

Microstructural changes of Aluminum Nitride after laser irradiation and electroless copper deposition

1994 ◽  
Vol 52 ◽  
pp. 636-637
Author(s):  
S. Cao ◽  
A. J. Pedraza ◽  
L. F. Allard
Keyword(s):  
Aluminum Nitride ◽  
Laser Irradiation ◽  
Electroless Deposition ◽  
Thermal Evaporation ◽  
Surface Region ◽  
Near Surface ◽  
Laser Patterning ◽  
Electroless Copper ◽  
Excimer Laser Irradiation ◽  
Laser Effect

Excimer-laser irradiation strongly modifies the near-surface region of aluminum nitride (AIN) substrates. The surface acquires a distinctive metallic appearance and the electrical resistivity of the near-surface region drastically decreases after laser irradiation. These results indicate that Al forms at the surface as a result of the decomposition of the Al (which has been confirmed by XPS). A computer model that incorporates two opposing phenomena, decomposition of the AIN that leaves a metallic Al film on the surface, and thermal evaporation of the Al, demonstrated that saturation of film thickness and, hence, of electrical resistance is reached when the rate of Al evaporation equals the rate of AIN decomposition. In an electroless copper bath, Cu is only deposited in laser-irradiated areas. This laser effect has been designated laser activation for electroless deposition. Laser activation eliminates the need of seeding for nucleating the initial layer of electroless Cu. Thus, AIN metallization can be achieved by laser patterning followed by electroless deposition.

Sign in / Sign up

Export Citation Format

Share Document