3D simulation for scatter light distribution of optical surface defects

2018 ◽  
Author(s):  
Huiting Chai ◽  
Pengfei Zhang ◽  
Yongying Yang ◽  
Jian Bai ◽  
Yihui Zhang
Keyword(s):  
Surface Defects ◽  
Light Distribution ◽  
3D Simulation ◽  
Optical Surface ◽  
Scatter Light

Spherical optical surface defects digitizing evaluation system

2018 ◽  
Author(s):  
Yihui Zhang ◽  
Fan Wu ◽  
Yongying Yang ◽  
Jian Bai ◽  
Huiting Chai ◽  
...  
Keyword(s):  
Evaluation System ◽  
Surface Defects ◽  
Optical Surface

Simulation of microscopic metal surfaces based on measured microgeometry

2017 ◽  
Vol 84 (7-8) ◽  
Author(s):  
Haiyue Yang ◽  
Tobias Haist ◽  
Marc Gronle ◽  
Wolfgang Osten
Keyword(s):  
Ray Tracing ◽  
Metal Surfaces ◽  
Surface Defects ◽  
Training Data ◽  
Surface Inspection ◽  
Approximation Methods ◽  
Optical Surface ◽  
Scalar Diffraction ◽  
Training Samples ◽  
Inspection Systems

AbstractLack of training data is one of the main problems when realizing optical surface inspection systems. In the best case, provision of enough representative training samples is difficult and most of the time expensive. In some cases, it is not possible at all. Here we present an alternative method where the surface defects are simulated. Thereby, we focus on metal surfaces in the microscale where diffraction phenomena start to play a major role. Ray tracing and scalar diffraction approximation methods are applied and compared.

Detection Status of Surface Defect for Precise Optical Element

2011 ◽  
Vol 291-294 ◽  
pp. 1733-1737
Author(s):  
Hong Yu Chu ◽  
Zhi Jiang Xie ◽  
Xu Xu ◽  
Li Dan Zhou ◽  
Qin Liu
Keyword(s):  
Large Scale ◽  
Surface Defect ◽  
Surface Defects ◽  
Optical Element ◽  
Solid State Laser ◽  
Optical Surface ◽  
Laser Device ◽  
Technical Problems ◽  
Detection Technology ◽  
Surface Flaws

The optical surface defects have a significant impact on functions and reliability of the whole optical system. In recent years, with the great attention on research of large-scale high-power solid-state laser device at home and abroad, the detection of optical surface defect has also been highly valued. Through continuous exploration, defect detection technology has made some achievements, but there are still some urgent technical problems to be solved. In this paper, the technology situation of optical surface defect will be summarized in two aspects: the surface cleanliness and surface flaws. Moreover, the technical difficulties and the problems which are currently facing will be analysis.

Effects of Friction Modifier Additives on HDD Substrate Defects and Surface Topography during CMP

2013 ◽  
Vol 845 ◽  
pp. 894-898
Author(s):  
Salleh Sideq ◽  
S. Izman
Keyword(s):  
Surface Topography ◽  
Chemical Mechanical Polishing ◽  
Surface Defects ◽  
Substrate Surface ◽  
Disk Drive ◽  
Optical Surface ◽  
Friction Modifier ◽  
Atomic Force ◽  
Afm Analysis ◽  
Substrate Defects

This study investigates the effects of Friction Modifier Additives (FMA) added into the polishing slurry on Aluminium Nickel Phosphorous plated (Al-NiP) Hard-Disk Drive (HDD) substrates surface topography and surface defects during Chemical Mechanical Polishing (CMP) process. It is confirmed that addition of Friction Modifier Additives into the slurry reduces the overall coefficient of friction (CoF) during CMP process. By increasing the FMA concentration in the polishing slurry, the substrate surface topography such as waviness and surface roughness were improved significantly. It also lowered the defects counts especially scratch and sub-micron damage as revealed under Optical Surface Analyser (OSA) and Atomic Force Microscope (AFM) analysis.

Variation of the amount of hydrogen along the galactic ridge

1967 ◽  
Vol 31 ◽  
pp. 171-172
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Surface Brightness ◽  
Milky Way ◽  
Neutral Hydrogen ◽  
Line Of Sight ◽  
Optical Surface ◽  
Hydrogen Density ◽  
Continuous Radiation ◽  
Galactic Longitude

The integralNHof neutral-hydrogen density along the line of sight is determined from the Kootwijk and Sydney surveys. The run ofNHwith galactic longitude agrees well with that of thermal continuous radiation and that of the optical surface brightness of the Milky Way.

Defects in Crystals

1968 ◽  
Vol 26 ◽  
pp. 244-245
Author(s):  
Kenneth R. Lawless
Keyword(s):  
Electron Microscope ◽  
Point Defects ◽  
Surface Defects ◽  
Chemical Properties ◽  
Material Point ◽  
Crystal Defects ◽  
Defects In Crystals ◽  
Irradiation Effects ◽  
Normal Lattice ◽  
Line Defects

One of the most important applications of the electron microscope in recent years has been to the observation of defects in crystals. Replica techniques have been widely utilized for many years for the observation of surface defects, but more recently the most striking use of the electron microscope has been for the direct observation of internal defects in crystals, utilizing the transmission of electrons through thin samples.Defects in crystals may be classified basically as point defects, line defects, and planar defects, all of which play an important role in determining the physical or chemical properties of a material. Point defects are of two types, either vacancies where individual atoms are missing from lattice sites, or interstitials where an atom is situated in between normal lattice sites. The so-called point defects most commonly observed are actually aggregates of either vacancies or interstitials. Details of crystal defects of this type are considered in the special session on “Irradiation Effects in Materials” and will not be considered in detail in this session.

Characterization of homoepitaxial diamond films by Electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 880-881
Author(s):  
D.P. Malta ◽  
S.A. Willard ◽  
R.A. Rudder ◽  
G.C. Hudson ◽  
J.B. Posthill ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Defects ◽  
Substrate Surface ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Large Degree ◽  
Rf Plasma ◽  
Semiconducting Diamond

Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. A major goal of current device-related diamond research is to achieve a high quality epitaxial film on an inexpensive, readily available, non-native substrate. One step in the process of achieving this goal is understanding the nucleation and growth processes of diamond films on diamond substrates. Electron microscopy has already proven invaluable for assessing polycrystalline diamond films grown on nonnative surfaces.The quality of the grown diamond film depends on several factors, one of which is the quality of the diamond substrate. Substrates commercially available today have often been found to have scratched surfaces resulting from the polishing process (Fig. 1a). Electron beam-induced current (EBIC) imaging shows that electrically active sub-surface defects can be present to a large degree (Fig. 1c). Growth of homoepitaxial diamond films by rf plasma-enhanced chemical vapor deposition (PECVD) has been found to planarize the scratched substrate surface (Fig. 1b).

Microstructure of sputter deposited Ni-Sb ohmic contacts on GaAs

1989 ◽  
Vol 47 ◽  
pp. 450-451
Author(s):  
S. Yegnasubramanian ◽  
V.C. Kannan ◽  
R. Dutto ◽  
P.J. Sakach
Keyword(s):  
High Performance ◽  
Ohmic Contacts ◽  
Surface Defects ◽  
Pure Metal ◽  
Device Fabrication ◽  
Native Oxide ◽  
Metal Thin Films ◽  
Recent Developments ◽  
Different Temperatures ◽  
Sputter Deposited

Recent developments in the fabrication of high performance GaAs devices impose crucial requirements of low resistance ohmic contacts with excellent contact properties such as, thermal stability, contact resistivity, contact depth, Schottky barrier height etc. The nature of the interface plays an important role in the stability of the contacts due to problems associated with interdiffusion and compound formation at the interface during device fabrication. Contacts of pure metal thin films on GaAs are not desirable due to the presence of the native oxide and surface defects at the interface. Nickel has been used as a contact metal on GaAs and has been found to be reactive at low temperatures. Formation Of Ni2 GaAs at 200 - 350C is reported and is found to grow epitaxially on (001) and on (111) GaAs, but is shown to be unstable at 450C. This paper reports the investigations carried out to understand the microstructure, nature of the interface and composition of sputter deposited and annealed (at different temperatures) Ni-Sb ohmic contacts on GaAs by TEM. Attempts were made to correlate the electrical properties of the films such as the sheet resistance and contact resistance, with the microstructure. The observations are corroborated by Scanning Auger Microprobe (SAM) investigations.

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