Photo-Chemical Etching on Silicon-Carbide by Using Krf Excimer Laser and Xe2* Excimer Lamp

1995 ◽  
Vol 397 ◽  
Author(s):  
K. Hasegawa ◽  
M. Murahara
Keyword(s):  
Silicon Carbide ◽  
Chemical Etching ◽  
Laser Light ◽  
Sample Surface ◽  
High Melting Point ◽  
Excimer Lamp ◽  
Photochemical Etching ◽  
Gas Atmosphere ◽  
Krf Laser ◽  
Krf Excimer Laser

ABSTRACTSilicon-carbide (SiC) has excellent refractivity in the range of soft X-ray and is well-used as a diffraction grating for Synchrotron-radiation (SR) light. This material has a high melting point, hardness and chemical stability. Therefore, etching of the material by chemical or physical methods is very difficult. We reported a photo-chemical etching method in which a SiC surface is placed in NF3 gas atmosphere and irradiated by the Xe2* excimer lamp light parallelly and the grating patterned KrF laser light of 248nm perpendicularly on the sample surface. The Xe2* excimer lamp light are employed for NF3 gas decomposition, and KrF laser light used for excitation on the sample surface. This photochemical etching reaction are detected by XPS, QMS and FTIR measurements. This method achieved 0.18 Å/shot in etching efficiency, and became maximum approximately 7 times as high as ArF laser light for photodecomposition.

Photochemical Pattern Etching of Single-Crystalline 3C-SiC

1997 ◽  
Vol 495 ◽  
Author(s):  
T. Mori ◽  
K. Hatao ◽  
M. Murahara
Keyword(s):  
Excimer Laser ◽  
Surface Reaction ◽  
Laser Light ◽  
Sample Surface ◽  
Etch Depth ◽  
Reaction Cell ◽  
Single Crystalline ◽  
Excimer Lamp ◽  
Krf Laser ◽  
Krf Excimer Laser

ABSTRACTA single-crystalline 3C-SiC is very difficult to etch compared with a polycrystalline SiC. Thus, a photochemical pattern etching of the SiC was demonstrated by using Xe2* excimer lamp and ArF or KrF excimer laser. To promote the surface reaction, a Xe2* excimer lamp was employed to produce many radicals on the sample surface; simultaneously, ArF or KrF laser light irradiated the surface via a circuit pattern to dissociate the Si-C bonds. The Si and C reacted with the F and N radicals photo-dissociated from NF3 gas to form SiF4, CFn and CN, which diffused in the reaction cell. As a result, the single-crystalline 3C-SiC was photo-chemically etched effectively. With the NF3 gas of 200Torr, the Xe2* excimer lamp of 7mW/cm2, and the KrF excimer laser of 650mJ/cm2, 20Hz and 10,000shots, the etch depth of 700 Å was successfully achieved.

scholarly journals Fabrication of Silicon Carbide Quantum Dots via Chemical-Etching Approach and Fluorescent Imaging for Living Cells

2014 ◽  
Vol 05 (04) ◽  
pp. 177-182
Author(s):  
Yuepeng Song ◽  
Dongsheng Gao ◽  
Hyoung Seop Kim ◽  
Cuiqin Qu ◽  
Jie Kang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Silicon Carbide ◽  
Chemical Etching ◽  
Living Cells ◽  
Fluorescent Imaging

scholarly journals Decontamination Effect of the Spindle and 222-Nanometer Krypton-Chlorine Excimer Lamp Combination against Pathogens on Apples (Malus domesticaBorkh.) and Bell Peppers (Capsicum annuumL.)

2019 ◽  
Vol 85 (12) ◽  
Author(s):  
Jun-Won Kang ◽  
Dong-Hyun Kang
Keyword(s):  
Pathogenic Bacteria ◽  
Fresh Produce ◽  
Free Water ◽  
Consumer Preference ◽  
Sample Surface ◽  
Bell Pepper ◽  
Tween 20 ◽  
Content Type ◽  
Excimer Lamp ◽  
Serovar Typhimurium

ABSTRACTIn this study, we developed a washing system capable of decontaminating fresh produce by combining the Spindle apparatus, which detaches microorganisms on sample surfaces, and a 222-nm krypton-chlorine excimer lamp (KrCl excilamp) (Sp-Ex) and investigated their decontamination effect againstEscherichia coliO157:H7,Salmonella entericaserovar Typhimurium, andListeria monocytogeneson apple (Malus domesticaBorkh.) and bell pepper (Capsicum annuumL.) surfaces. Initial levels of the three pathogens were approximately 108CFU/sample. BothE. coliO157:H7 andS.Typhimurium were reduced to below the detection limit (2.0 log CFU/sample) after 5 and 7 min of treatment on apple and bell pepper surfaces, respectively. The amounts ofL. monocytogeneson apple and bell pepper surfaces were reduced by 4.26 and 5.48 logs, respectively, after 7 min of treatment. The decontamination effect of the Sp-Ex was influenced by the hydrophobicity of the sample surface as well as the microbial cell surface, and the decontamination effect decreased as the two hydrophobicity values increased. To improve the decontamination effect of the Sp-Ex, Tween 20, a surfactant that weakens the hydrophobic interaction between the sample surface and pathogenic bacteria, was incorporated into Sp-Ex processing. It was found that its decontamination effect was significantly (P < 0.05) increased by the addition of 0.1% Tween 20. Sp-Ex did not cause significant quality changes in apple or bell pepper surfaces during 7 days storage following treatment (P > 0.05). Our results suggest that Sp-Ex could be applied as a system to control pathogens in place of chemical sanitizer washing by the fresh-produce industry.IMPORTANCEAlthough most fresh-produce processing currently controls pathogens by means of washing with sanitizers, there are still problems such as the generation of harmful substances and changes in product quality. A combination system composed of the Spindle and a 222-nm KrCl excilamp (Sp-Ex) developed in this study reduced pathogens on apple and bell pepper surfaces using sanitizer-free water without altering produce color and texture. This study demonstrates the potential of the Sp-Ex to replace conventional washing with sanitizers, and it can be used as baseline data for practical application by industry. In addition, implementation of the Sp-Ex developed in this study is expected not only to meet consumer preference for fresh, minimally processed produce but also to reduce human exposure to harmful chemicals while being beneficial to the environment.

Improving Mechanical Strength and Surface Uniformity to Prepare High Quality Thinned 4H-SiC Epitaxial Wafer Using Si-Vapor Etching Technology

2017 ◽  
Vol 897 ◽  
pp. 375-378 ◽  
Author(s):  
Satoshi Torimi ◽  
Koji Ashida ◽  
Norihito Yabuki ◽  
Masato Shinohara ◽  
Takuya Sakaguchi ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Mechanical Strength ◽  
Chemical Etching ◽  
Imaging Technique ◽  
Low Energy ◽  
Indentation Hardness ◽  
High Quality ◽  
Surface Step ◽  
Low Energy Electron ◽  
Sic Wafer

As a new thinning and surface planarizing process of Silicon Carbide (SiC) wafer, we propose the completely thermal-chemical etching process; Si-vapor etching (Si-VE) technology. In this work, the effects of mechanical strength and surface step-terrace structure by Si-VE are investigated on the 4° off-axis 4H-SiC (0001) Si-face substrates. The indentation hardness of Si-VE surface is superior to the conventional chemo-mechanical polishing (CMP) surface even after epitaxial growth. The transverse strength of thinned Si-VE substrate is also superior to the conventional mechanically ground substrate. The surface step-terrace structures are observed by the low energy electron channeling contrast (LE-ECC) imaging technique. The latent scratch causes bunched step lines (BSLs) with various inhomogeneous step morphologies only on the CMP surface.

BPD-TED Conversion in the SiC Substrate after High-Temperature Si-VE

2020 ◽  
Vol 1004 ◽  
pp. 401-407
Author(s):  
Yusuke Sudoh ◽  
Makoto Kitabatake ◽  
Tadaaki Kaneko
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Chemical Etching ◽  
Surface Region ◽  
Etching Process ◽  
Koh Etching

We propose the Si-Vapor Etching (Si-VE), which is thermal chemical etching process, as epi-ready treatment for Silicon Carbide (SiC). In this work, we report the evaluation results of BPD-TED conversion by Si-VE treatment using repeated KOH etching process. This method makes it possible to observe BPD-TED conversion in a very shallow surface region of the SiC substrate. 80% of BPDs is converted to TEDs with a depth of more than 80nm under optimized Si-VE 2000°C conditions. Furthermore, 53% of BPDs were converted to TEDs with 140nm or more depth, which has been confirmed under optimized 1800°C Si-VE conditions.

scholarly journals Buckling Porous SiC Membranes

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 785
Author(s):  
Markus Leitgeb ◽  
Christopher Zellner ◽  
Manuel Dorfmeister ◽  
Michael Schneider ◽  
Ulrich Schmid
Keyword(s):  
Thin Film ◽  
Silicon Carbide ◽  
Crystalline Silicon ◽  
Single Crystalline Silicon ◽  
Design Concepts ◽  
Photochemical Etching ◽  
Potential Applications ◽  
Etching Parameters ◽  
Porous Sic ◽  
Highly Porous

In preliminary studies it could be shown that single crystalline silicon carbide wafers can be porosified with metal assisted photochemical etching. Furthermore, the generation of porous areas which are locally defined is possible with this method. By adjusting the etching parameters, a highly porous layer (degree of porosity of 90%) can be formed which is under-etched by a line of breakage. By depositing a compressively stressed amorphous SiC:H thin film on top of a porous region, the a-SiC:H film can be locally separated from the substrate, resulting in a buckled membrane configuration. Such membranes might open up potential applications in MEMS design concepts.

scholarly journals High Temperature Texture Goniometer for in Situ Measurements of Transformation Textures

1998 ◽  
Vol 30 (3-4) ◽  
pp. 125-132
Author(s):  
G. Brückner ◽  
F. R. Reher ◽  
G. Gottstein
Keyword(s):  
High Temperature ◽  
Texture Evolution ◽  
Sample Surface ◽  
Texture Measurement ◽  
X Ray ◽  
Reducing Gas ◽  
Gas Atmosphere ◽  
Computer Controlled

A high temperature stage was designed for mounting onto a computer controlled four circle X-ray texture goniometer. This technique allowed to conduct in situ texture measurement, i.e. the determination of the texture evolution during rather than subsequent to annealing. The device was employed for temperatures up to 1000°C.The furnace consisted of a resistance wire of Pt30Rh, which was isolated against the specimen with Al2O3 glue. The furnace with the specimen was covered by a hemispherical KaptonTM foil. Inside the hemisphere a reducing gas atmosphere was used to avoid oxidation of the sample surface.

Crystal Quality and Orientation of Pulsed Laser Deposited Barium Titanate Thin Films

1998 ◽  
Vol 526 ◽  
Author(s):  
J. Gottmann ◽  
T. Klotzbücher ◽  
B. Vosseler ◽  
E. W. Kreutz
Keyword(s):  
Thin Films ◽  
Kinetic Energy ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
X Ray Diffraction ◽  
Oriented Growth ◽  
Axis Orientation ◽  
Film Forming ◽  
Gas Atmosphere ◽  
Krf Excimer Laser

AbstractKrF excimer laser radiation (λ=248 nm, τ=25 ns) is used for pulsed laser deposition of BaTiO3 thin films on Pt/Ti/Si multilayer substrates. The processing gas atmosphere consists of O2 at typical pressures of p=10-3-5·10-1 mbar. The investigations concentrate on the influence of the substrate temperature and the kinetic energy of the film forming particles on the crystalline structure and orientation of the growing films.X-ray diffraction measurements and polarization dependent micro Raman spectroscopy reveal oriented growth of the films with c-axis orientation normal to the substrate surface and [100] texture if the energy of the particles is > 60 eV, while at lower kinetic energies a [110] or [111] texture with partly a-axis orientation is preferred. The ferroelectricity and the dielectric constant of the films, as determined by polarization versus voltage (P-V) and capacitance versus voltage (C-V) impedance measurements, decreases with increasing kinetic energy of the film forming particles. This decrease of the dielectric properties correlates with the change of the preferred orientation and the crystalline quality of the films.

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