Investigation on surface roughness and sub-surface damage in ISF

2018 ◽  
Vol 13 (4) ◽  
pp. 287
Author(s):  
Yicun Meng ◽  
Sheng Liu
Keyword(s):  
Surface Roughness ◽  
Surface Damage

Reactive Ion Etching Induced Surface Damage of Silicon Carbide

2005 ◽  
Vol 483-485 ◽  
pp. 765-768 ◽  
Author(s):  
Jun Hai Xia ◽  
E. Rusli ◽  
R. Gopalakrishnan ◽  
S.F. Choy ◽  
Chin Che Tin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Reactive Ion Etching ◽  
Surface Damage ◽  
Textured Surface ◽  
Rf Power ◽  
Power Devices ◽  
Ion Etching ◽  
Maximum Value ◽  
Wide Range ◽  
Coarse Surface

Reactive ion etching of SiC induced surface damage, e.g., micromasking effect induced coarse and textured surface, is one of the main concerns in the fabrication of SiC based power devices [1]. Based on CHF3 + O2 plasma, 4H-SiC was etched under a wide range of RF power. Extreme coarse and textured etched surfaces were observed under certain etching conditions. A super-linear relationship was found between the surface roughness and RF power when the latter was varied from 40 to 160 W. A further increase in the RF power to 200 W caused the surface roughness to drop abruptly from its maximum value of 182.4 nm to its minimum value of 1.3 nm. Auger electron spectroscopy (AES) results revealed that besides the Al micromasking effect, the carbon residue that formed a carbon-rich layer, could also play a significant role in affecting the surface roughness. Based on the AES results, an alternative explanation on the origin of the coarse surface is proposed.

Temperature Dependence of Surface Morphology of Silicon Grown on CaF2/Si by Electron Beam Assisted Mbe

1994 ◽  
Vol 367 ◽  
Author(s):  
P.O. Pettersson ◽  
R.J. Miles ◽  
T.C. Mcgill
Keyword(s):  
Surface Roughness ◽  
Electron Beam ◽  
Photoelectron Spectroscopy ◽  
Silicon Layer ◽  
Surface Damage ◽  
Low Energy ◽  
Growth Mode ◽  
Optimal Range ◽  
Low Energy Electrons ◽  
Ordered Array

AbstractWe present the results of electron beam assisted molecular beam epitaxy (EB-MBE) on the growth mode of silicon on CaF2/Si(111). By irradiating the CaF2 surface with low energy electrons, the fluorine is desorbed, leaving an ordered array of F-centers behind. Using atomic force microscopy (AFM), we do not detect any surface damage on the CaF2 layer due to the low energy electron irradiation. The surface free energy of the CaF2 is raised due to the F-center array and the subsequent silicon layer is smoother. Using AFM and X-ray photoelectron spectroscopy (XPS), we find an optimal range of exposures for high temperature (650°C) growth of the silicon overlayer that minimizes surface roughness of the silicon overlayer and we present a simple model based on geometrical thermodynamics to explain this.We observed a similar optimal range of exposures that minimizes the surface roughness for medium (575°C) and low (500°C) growth temperatures of the silicon layer. We present an explanation for this growth mode based on kinetics.

Tubing String Thread Sealing Surfaces Damage Evaluation Based on Acoustic Elasticity Theory

2019 ◽  
Vol 944 ◽  
pp. 828-834 ◽  
Author(s):  
Jian Jun Wang ◽  
Jian Hua Sun ◽  
Shang Yu Yang ◽  
Yao Rong Feng ◽  
Kai Lin
Keyword(s):  
Surface Roughness ◽  
Elasticity Theory ◽  
Contact Stress ◽  
Surface Characterization ◽  
Surface Damage ◽  
Center Frequency ◽  
Sealing Performance ◽  
Tubing String ◽  
Acoustic Elasticity

During the processing of tubing premium threaded made up, the degree of the thread sealing surface intactness will directly affect the sealing performance of the string. Nevertheless, there are some difficulties to detect the damage of the engaged sealing surface effectively. In the present study the sealing surface damage was judged by the sealing surface contact stress’s relative changes according to the acoustic elasticity theory,. At the same time, the wear defects generated at the tubing sealing surface, during the tubing made up, contrasted with the wear and unworn surface roughness of coupling ultrasonic detected about the sealing surface. The results showed that with the acoustic amplitude evaluated the sealing contact stress was susceptible to the influence of surface roughness of coupling. But the reflection wave with the center frequency on the sealing surface characterization of the contact stress could avoid this problem effectively.

Periodic Surface Damage in Germanium: The Spectrum in K→ Space and its Theoretical Interpretation

1981 ◽  
Vol 4 ◽  
Author(s):  
Jeff F. Young ◽  
J. E. Sipe ◽  
M. I. Gallant ◽  
J. S. Preston ◽  
H. M. Van Driel
Keyword(s):  
Surface Roughness ◽  
Fourier Transforms ◽  
Surface Damage ◽  
Laser Pulses ◽  
Theoretical Interpretation ◽  
Periodic Surface ◽  
Yag Laser ◽  
Damage Structure

ABSTRACTThe Fourier transforms of the grating-like damage patterns formed on the surface of Ge by single 1.06μm YAG laser pulses reveal a great deal of information about the damage structure. A theory is presented based on scattering from surface roughness which accurately accounts for both the spacing and orientation of the fringes produced at various angles of incidence by beams of different polarizations.

Optimization of Coated SiC Belt Grinding of Alumina Ceramics

2009 ◽  
Vol 76-78 ◽  
pp. 38-42 ◽  
Author(s):  
Xavier Kennedy ◽  
S. Gowri
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
High Hardness ◽  
Surface Damage ◽  
High Temperature Strength ◽  
Structural Ceramics ◽  
Alumina Ceramics ◽  
Belt Grinding ◽  
Grinding Parameters ◽  
Surface Damages

Advanced structural ceramics have been increasingly used in automotive, aerospace, military, medical and other applications due to their high temperature strength, low density, thermal and chemical stability. However, the Grinding of advanced ceramics such as alumina is difficult due to its low fracture toughness and sensitivity to cracking, high hardness and brittleness. In this paper, surface integrity and material removal mechanisms of Alumina ceramics ground with SiC abrasive belts, have been investigated. The surface damage have been studied with scanning electron microscope (SEM). The significance of grinding parameters on the responses was evaluated using Signal to Noise ratios.This research links the surface roughness and surface damages to grinding parameters. The optimum levels for maximum material removal and surface roughness been discussed.

Study of Magnetorheological Brush Finishing (MRBF) for Concave Surface of Conformal Optics

2012 ◽  
Vol 497 ◽  
pp. 170-175
Author(s):  
Yun Zhang ◽  
Jing Feng Zhi ◽  
Yue Wang Yu ◽  
Xu Xing Zhu ◽  
Wei Zuo
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Surface Damage ◽  
Aspheric Surface ◽  
Precision Turning ◽  
Good Surface ◽  
Steel Material ◽  
Stainless Steel Material ◽  
Ultra Precision ◽  
Magnetorheological Polishing

Stainless steel; Aspheric mould; Ultra-precision turning; Magnetorheological polishing The ultra precision turning and the inclined-axis type of magnetorheological polishing were introduced for the small aspheric mould of stainless steel. The method was based on the principle of two kinds of processing methods, and the processing feature of stainless steel material. Firstly, the ultra-precision turning was employed to shape aspheric surface rapidly and obtain a relatively good surface. And then, the inclined-axis type of magnetorheological polishing as the final finishing was used to decrease sub-surface damage to obtain better precision. Several of experiments were carried out, the experimental results show that surface roughness can be achieved for Ra 0.0073μm.

Prediction of Surface Quality for Silicon Carbide Wheel Grinding of Silicon Nitride

2006 ◽  
Vol 532-533 ◽  
pp. 297-300
Author(s):  
Li Ming Xu ◽  
Albert J. Shih ◽  
Bin Shen ◽  
Chun Xiang Ma ◽  
De Jin Hu
Keyword(s):  
Surface Roughness ◽  
Silicon Carbide ◽  
Silicon Nitride ◽  
Surface Quality ◽  
Prediction Accuracy ◽  
Surface Damage ◽  
Small Samples ◽  
Support Vector ◽  
Grinding Parameters ◽  
Grinding Efficiency

The experimental results for silicon carbide (SiC) wheel with fine grit size grinding of silicon carbide (Si3N4) revealed that the grinding parameters affect not only the ground silicon nitride surface roughness, but also the degree of surface damage. There exists complex non-linear relationship between the grinding parameters and surface quality. Better surface roughness doesn’t surely mean less surface damage. A method of prediction of grinding quality based on support vector regression is then presented according to the condition of small samples. The result shows the prediction accuracy based on this method is obviously higher than neural network, which provides an effective way for optimizing the grinding parameters to ensure the grinding quality as well as grinding efficiency while grinding of silicon carbide using conventional abrasive.

Diamond Coated End Mills in Machining Silicon Carbide

2012 ◽  
Vol 576 ◽  
pp. 531-534 ◽  
Author(s):  
Mohamed Konneh ◽  
Mohammad Iqbal ◽  
Nik Mohd Azwan Faiz
Keyword(s):  
Surface Roughness ◽  
Silicon Carbide ◽  
High Performance ◽  
Removal Rate ◽  
Roughness Parameter ◽  
Surface Damage ◽  
Ceramic Materials ◽  
Real Problem ◽  
Machining Parameters ◽  
Machining Processes

Silicon Carbide (SiC) is a type of ceramic that belongs to the class of hard and brittle material. Machining of ceramic materials can result in surface alterations including rough surface, cracks, subsurface damage and residual stresses. Efficient milling of high performance ceramic involves the selection of appropriate operating parameters to maximize the material removal rate (MRR) while maintaining the low surface finish and limiting surface damage. SiC being a ceramic material, its machining poses a real problem due to its low fracture toughness, making it very sensitive to crack. The paper discusses milling of silicon carbide using diamond coated end mill under different machining conditions in order to determine the surface roughness parameter, Rt after the machining processes and to establish a relationship between the machining parameters and response variables. Based on the surface roughness carried out the lowest Rt obtained is 0.46 µm.

Assessment of Quantitative Methodology for Evaluation of Retrieved Metallic Femoral Components From Total Knee Replacements

2011 ◽  
Author(s):  
Estefania Alvarez ◽  
Marcella E. Elpers ◽  
Hillary M. Cash ◽  
Michelle E. Wabler ◽  
John D. DesJardins
Keyword(s):  
Surface Roughness ◽  
Femoral Component ◽  
Joint Replacement ◽  
Total Joint Replacement ◽  
Articular Surface ◽  
Surface Profile ◽  
Surface Damage ◽  
Damage Score ◽  
Visual Damage

The metallic surfaces of total joint replacement components are subject to surface damage and roughening that can severely limit the service lifetime of the bearing system. To date, there are no standards by which to characterize the severity and modes of this critical surface damage, and therefore it remains difficult to accurately assess how femoral damage influences total joint replacement longevity. This study introduces a novel femoral component damage scoring methodology that combines a semi-quantitative visual damage scoring assessment and a fully quantitative non-contact characterization of the articular surface profile. The femoral surface was divided into 6 pre-determined zones, with 5 possible modes of damage and 4 (0–3) levels of damage severity, to produce a maximum possible damage score of 90. The 5 modes of metallic surface damage were; number of scratches, scratch depth, third body wear, abrasion and pitting. Three independent examiners were trained and then evaluated 33 retrieved TKRs systems (n = 11 Oxinium and n = 23 CoCr) with in-situ times of 3.6 ± 4.2 yrs (range of 0.1–20 yrs). The average damage score was 19.9 ± 30.8 with an inter-observer variability of only 1.5% Articular damage mode frequency was calculated and found to be 61% for scratching, 15% for pitting and 52% for abrasion. The quantitative characterization of the articular surface profile of the femoral component using non-contact profilometry (n = 150/retrieved component) illustrated a positive correlation between damage score and the average surface roughness for implants with an Ra greater than 65 nm (R2 of 0.865). This methodology identified a critical Ra threshold above the standard manufacturing tolerance (∼50nm) wherein visual damage scoring was predictive of increases in quantitative surface roughness. This study validates the use of this novel methodology across most TKR material pairings. Future work will correlate damage scores and measured surface roughness with patient demographic and functional information.

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