Semiconductor Optoelectronic Device Fabrication Using Dry Etching

1988 ◽  
Vol 144 ◽  
Author(s):  
Adam J. Carter ◽  
Ben Thomas ◽  
David V. Morgan ◽  
Jyoti K. Bhardwaj
Keyword(s):  
Surface Roughness ◽  
Plasma Etching ◽  
Surface Characteristics ◽  
Optoelectronic Device ◽  
Dry Etching ◽  
Device Fabrication ◽  
Material Composition ◽  
Process Gas ◽  
Etched Surface

ABSTRACTPlasma etching of GaAs and InP using a CH4/H2 process gas and AlxGa1−xAs using a SiCl4 plasma are reported. Particular attention to etching characteristics as a function of gas and material composition, r.f. power, pressure and temperature are shown. Etching of GaAs and InP highlight two separate etching mechanisms. Surface roughness data at the etched surface is presented and Cl and CH4/H2 process chemistries are compared which shows the latter to yield significant improvements in etch surface characteristics.

Surface Characteristics of Monocrystalline ß-SiC dry etched in fluorinated gases

1986 ◽  
Vol 76 ◽  
Author(s):  
John W. Palmour ◽  
R. F. Davis ◽  
P. Astell-Burt ◽  
P. Blackborow
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Plasma Etching ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Surface Characteristics ◽  
Native Oxide ◽  
Surface Plasma ◽  
Etched Surface ◽  
Scanning Electron

ABSTRACTMonocrystalline ß-SiC (100) thin films were dry etched in CF4 and NF3 by reactive ion etching (RIE) and in SF6 by plasma etching. The etched surfaces were characterized by Auger Electron Spectroscopy (AES) and Scanning Electron Microscopy (SEM). The use of a stainless steel or an anodized Al cathode during RIE created a roughened SiC surface, which was contaminated with Fe or Al2 O3respectively. The roughness was caused by a micromasking effect produced by the deposition of these contaminants. By contrast, a carbon cathode yielded a very smooth and a much cleaner etched surface. Plasma etching of SiC in SF6 resulted in a very rough surface, but the AES spectra indicated almost no contamination and very little native oxide or fluorine. The optimal condition for etching SiC was determined to be RIE in NF 3 on a C cathode.

Silicon layers grown over SiO2 by liquid phase epitaxy: Electron Microscopical study

1990 ◽  
Vol 48 (4) ◽  
pp. 566-567
Author(s):  
F. Banhart ◽  
F.O. Phillipp ◽  
R. Bergmann ◽  
E. Czech ◽  
M. Konuma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Liquid Phase ◽  
Plasma Etching ◽  
Liquid Phase Epitaxy ◽  
Three Dimensional ◽  
Microscopical Study ◽  
Sample Temperature ◽  
Structural Defects ◽  
Si Substrates ◽  
Etched Surface

Defect-free silicon layers grown on insulators (SOI) are an essential component for future three-dimensional integration of semiconductor devices. Liquid phase epitaxy (LPE) has proved to be a powerful technique to grow high quality SOI structures for devices and for basic physical research. Electron microscopy is indispensable for the development of the growth technique and reveals many interesting structural properties of these materials. Transmission and scanning electron microscopy can be applied to study growth mechanisms, structural defects, and the morphology of Si and SOI layers grown from metallic solutions of various compositions.The treatment of the Si substrates prior to the epitaxial growth described here is wet chemical etching and plasma etching with NF3 ions. At a sample temperature of 20°C the ion etched surface appeared rough (Fig. 1). Plasma etching at a sample temperature of −125°C, however, yields smooth and clean Si surfaces, and, in addition, high anisotropy (small side etching) and selectivity (low etch rate of SiO2) as shown in Fig. 2.

scholarly journals Biofilm inhibition and bactericidal activity of NiTi alloy coated with graphene oxide/silver nanoparticles via electrophoretic deposition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sirapat Pipattanachat ◽  
Jiaqian Qin ◽  
Dinesh Rokaya ◽  
Panida Thanyasrisung ◽  
Viritpon Srimaneepong
Keyword(s):  
Surface Roughness ◽  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Electrophoretic Deposition ◽  
Biofilm Formation ◽  
Niti Alloy ◽  
Surface Characteristics ◽  
Dependent Manner ◽  
Biofilm Inhibition ◽  
Coating Time

AbstractBiofilm formation on medical devices can induce complications. Graphene oxide/silver nanoparticles (GO/AgNPs) coated nickel-titanium (NiTi) alloy has been successfully produced. Therefore, the aim of this study was to determine the anti-bacterial and anti-biofilm effects of a GO/AgNPs coated NiTi alloy prepared by Electrophoretic deposition (EPD). GO/AgNPs were coated on NiTi alloy using various coating times. The surface characteristics of the coated NiTi alloy substrates were investigated and its anti-biofilm and anti-bacterial effect on Streptococcus mutans biofilm were determined by measuring the biofilm mass and the number of viable cells using a crystal violet assay and colony counting assay, respectively. The results showed that although the surface roughness increased in a coating time-dependent manner, there was no positive correlation between the surface roughness and the total biofilm mass. However, increased GO/AgNPs deposition produced by the increased coating time significantly reduced the number of viable bacteria in the biofilm (p < 0.05). Therefore, the GO/AgNPs on NiTi alloy have an antibacterial effect on the S. mutans biofilm. However, the increased surface roughness does not influence total biofilm mass formation (p = 0.993). Modifying the NiTi alloy surface using GO/AgNPs can be a promising coating to reduce the consequences of biofilm formation.

Modeling of surface roughness in a novel magnetorheological gear profile finishing process

2020 ◽  
pp. 095440622097826
Author(s):  
Ravi Datt Yadav ◽  
Anant Kumar Singh ◽  
Kunal Arora
Keyword(s):  
Surface Roughness ◽  
Gear Tooth ◽  
Surface Characteristics ◽  
Spur Gear ◽  
Tooth Profile ◽  
Tooth Surface ◽  
Magnetic Flux Density ◽  
Element Analysis ◽  
Finishing Process ◽  
Gear Profile

Fine finishing of spur gears reduces the vibrations and noise and upsurges the service life of two mating gears. A new magnetorheological gear profile finishing (MRGPF) process is utilized for the fine finishing of spur gear teeth profile surfaces. In the present study, the development of a theoretical mathematical model for the prediction of change in surface roughness during the MRGPF process is done. The present MRGPF is a controllable process with the magnitude of the magnetic field, therefore, the effect of magnetic flux density (MFD) on the gear tooth profile has been analyzed using an analytical approach. Theoretically calculated MFD is validated experimentally and with the finite element analysis. To understand the finishing process mechanism, the different forces acting on the gear surface has been investigated. For the validation of the present roughness model, three sets of finishing cycle experimentations have been performed on the spur gear profile by the MRGPF process. The surface roughness of the spur gear tooth surface after experimentation was measured using Mitutoyo SJ-400 surftest and is equated with the values of theoretically calculated surface roughness. The results show the close agreement which ranges from −7.69% to 2.85% for the same number of finishing cycles. To study the surface characteristics of the finished spur gear tooth profile surface, scanning electron microscopy is used. The present developed theoretical model for surface roughness during the MRGPF process predicts the finishing performance with cycle time, improvement in the surface quality, and functional application of the gears.

scholarly journals Post-Processing and Surface Characterization of Additively Manufactured Stainless Steel 316L Lattice: Implications for BioMedical Use

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1376
Author(s):  
Alex Quok An Teo ◽  
Lina Yan ◽  
Akshay Chaudhari ◽  
Gavin Kane O’Neill
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Surface Characterization ◽  
High Surface ◽  
Surface Characteristics ◽  
Post Processing ◽  
Stainless Steel 316L ◽  
Processing Methods ◽  
Particulate Debris

Additive manufacturing of stainless steel is becoming increasingly accessible, allowing for the customisation of structure and surface characteristics; there is little guidance for the post-processing of these metals. We carried out this study to ascertain the effects of various combinations of post-processing methods on the surface of an additively manufactured stainless steel 316L lattice. We also characterized the nature of residual surface particles found after these processes via energy-dispersive X-ray spectroscopy. Finally, we measured the surface roughness of the post-processing lattices via digital microscopy. The native lattices had a predictably high surface roughness from partially molten particles. Sandblasting effectively removed this but damaged the surface, introducing a peel-off layer, as well as leaving surface residue from the glass beads used. The addition of either abrasive polishing or electropolishing removed the peel-off layer but introduced other surface deficiencies making it more susceptible to corrosion. Finally, when electropolishing was performed after the above processes, there was a significant reduction in residual surface particles. The constitution of the particulate debris as well as the lattice surface roughness following each post-processing method varied, with potential implications for clinical use. The work provides a good base for future development of post-processing methods for additively manufactured stainless steel.

Surface Roughness of Two CAD/CAM Restorative Materials as Affected by Chewing Simulation v1

2022 ◽  
Author(s):  
eaeldwakhly not provided
Keyword(s):  
Surface Roughness ◽  
Computer Aided Design ◽  
Surface Characteristics ◽  
Ceramic Materials ◽  
Study Groups ◽  
Significance Level ◽  
Chewing Simulation ◽  
Computer Aided ◽  
Cad Cam ◽  
The Individual

This study was conducted to assess the surface characteristics in terms of roughness of two CAD/CAM (Computer-Aided-Design/Computer-Aided Manufacturing)restorative material spre and post chewing simulation exposure. Methods: Specimens were prepared from two CAD/CAM ceramic materials: Cerec Blocs C and IPS e-max ZirCAD. A total of 10 disks were prepared for each study group. 3D optical noncontact surface profiler was used to test the surface roughness (ContourGT, Bruker, Campbell, CA, USA). A silicone mold was used to fix the individual samples using a self-curing resin. Surface roughness (SR) was examined pre and post exposure to chewing simulation. 480,000 simulated chewing cycles were conducted to mimic roughly two years of intraoral clinical service. The results data was first tested for normality and equal variance (Levene’s test >0.05) then examined with paired and independent sample t-test at a significance level of (p < 0.05). Results:The two CAD-CAM materials tested exhibited increased surface roughness from baseline. The highest mean surface roughness was observed in Cerec blocs C group after chewing simulation (2.34 µm± 0.62 µm). Whereas the lowest surface roughness was observed in IPS e.max ZirCAD group before chewing simulation (0.42 µm± 0.16 µm). Both study groups exhibited significantly different surface roughness values (p< 0.05). There was a statistically higher surface roughness values after the chewing simulation in Cerec blocs C when compared to IPS e.max ZirCAD groups (p = 0.000).Conclusion:Even though both tested CAD/CAM materials differ in recorded surface roughness values, results were within clinically accepted values.

A Chemical Perspective of GaN Polarity: The use of Hydrogen Plasma Dry Etching Versus NaOH Wet Etching to Determine Polarity

2002 ◽  
Vol 722 ◽  
Author(s):  
Maria Losurdo ◽  
MariaMichela Giangregorio ◽  
Pio Capezzuto ◽  
Giovanni Bruno ◽  
Gon Namkoong ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Plasma Etching ◽  
Hydrogen Plasma ◽  
Dry Etching ◽  
Surface Reactivity ◽  
Wet Etching ◽  
Hydrogen Treatment

AbstractThe use of dry hydrogen plasma etching is evaluated for determination of GaN polarity and critically compared to wet etching in NaOH. It is shown that hydrogen plasma etching is effective in revealing inversion domains (IDs) and some types of dislocations. This is because the surface morphology is unchanged by the hydrogen treatment, and, hence, the surface reactivity is not masked.

scholarly journals Surface Characteristics of Seersucker Woven Fabrics

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Malgorzata Matusiak ◽  
Vladimir Bajzik
Keyword(s):  
Surface Roughness ◽  
Evaluation System ◽  
Surface Friction ◽  
Surface Characteristics ◽  
Measurement Procedure ◽  
Woven Fabrics ◽  
Point Of View ◽  
Woven Fabric ◽  
Weft Yarn ◽  
Surface Parameters

AbstractThe surface characteristics of fabrics are important from the point of view of the sensorial comfort of clothing users. Surface friction and surface roughness are the most important surface parameters of fabrics. These parameters can be measured using different methods, the most important and well-accepted method being that using the Kawabata evaluation system (KES)-FB4 testing instrument. In this work, the surface roughness and surface friction of the seersucker woven fabric have been determined using the KES-FB4. However, the measurement procedure needs modification. On the basis of the results, the influence of the repeat of the seersucker effect and the linear density of the weft yarn on the surface parameters has been determined.

Sign in / Sign up

Export Citation Format

Share Document