A new method for high resolution curvature measurement applied to stress monitoring in thin films

2022 ◽  
Author(s):  
Sergey Grachev ◽  
Quentin Hérault ◽  
Jun Wang ◽  
Matteo Balestrieri ◽  
Hervé Montigaud ◽  
...  
Keyword(s):  
Compressive Stress ◽  
Film Growth ◽  
Image Correlation ◽  
New Method ◽  
Stress Monitoring ◽  
Correlation Algorithm ◽  
Curvature Measurement ◽  
Deposition Processes ◽  
Conventional Laser

Abstract By combining the well-known grid reflection method with a digital image correlation algorithm and a geometrical optics model, a new method is proposed for measuring the change of curvature of a smooth reflecting substrate, a common reporter of stress state of deposited layers. This tool, called Pattern Reflection for Mapping of Curvature (PReMC), can be easily implemented for the analysis of the residual stress during deposition processes and is sufficiently accurate to follow the compressivetensile-compressive stress transition during the sputtering growth of a Ag film on a Si substrate. Unprecedented resolution below 10-5m-1can be reached when measuring a homogeneous curvature. A comparison with the conventional laser-based tool is also provided in terms of dynamical range and resolution. In addition, the method is capable of mapping local variations in the case of a non-uniform curvature as illustrated by the case of a non-homogeneous Mo film under high compressive stress. PReMC offers interesting perspectives for in situ accurate stress monitoring in the field of thin film growth.

Real time in-situ stress evolution investigation of highly textured electrodeposited bismuth thin films

2003 ◽  
Vol 781 ◽  
Author(s):  
Donglei Fan ◽  
Frank Q. Zhu ◽  
Ingrid X. Shao ◽  
P. C. Searson ◽  
R. C. Cammarata
Keyword(s):  
Real Time ◽  
Compressive Stress ◽  
Film Growth ◽  
Stress Measurement ◽  
Mean Free Path ◽  
In Situ Stress ◽  
Stress Generation ◽  
In Situ Stress Measurement ◽  
Bismuth Films

AbstractBismuth, a semi-metal with very long mean free path and large magnetoresistance (MR) effect, is a novel candidate material for thin film spintronic devices. Electrochemical deposition followed by a post-deposition anneal has resulted in highly textured bismuth films as characterized by x-ray diffractometry and pole figure measurements. A highly sensitive, real time in-situ stress measurement system was designed and employed to study stress generation during bismuth film growth. Bismuth films displayed a monotonically increasing compressive stress during deposition. The magnitude of the compressive stress decreased with the deposition rate in the range 1.5 Å/sec to 50 Å/sec.

Direct Local Strain Measurement In Damascene Interconnects

2007 ◽  
Vol 990 ◽  
Author(s):  
Moustafa Kasbari ◽  
Christian Rivero ◽  
Sylvain Blayac ◽  
Florian Cacho ◽  
Ola Bostrom ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Local Stress ◽  
Local Strain ◽  
Geometrical Model ◽  
Copper Interconnects ◽  
Cmos Process ◽  
Stress Monitoring ◽  
Curvature Measurement ◽  
The One

ABSTRACTA new mechanical stress characterization method has been developed for Damascene copper interconnects. The micro strain gauge based on a rotating beam has been fabricated in situ on a standard industrial CMOS production line. Comparison of the beam deviation in the fabricated sensor with usual geometrical model is discussed. The saturation of the beam deviation leads to an analytical model which takes the stiffness of the anchoring points into account. This model gives a direct value of the local stress in the copper line for different annealing times. We show that this value is different from the one given by a curvature measurement method. The microstructure of the Damascene copper induces a higher stress level than full sheet deposition copper. The sensor was developed to be compatible within a CMOS process. It is suitable for in situ mechanical stress monitoring in Damascene lines and process optimization.

Direct Observations of the Epitaxial Growth of Sputtered Ag on Si

1973 ◽  
Vol 31 ◽  
pp. 122-123
Author(s):  
J. S. Maa ◽  
Thos. E. Hutchinson
Keyword(s):  
Epitaxial Growth ◽  
Film Growth ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
Microscopy Technique ◽  
Direct Observations ◽  
In Situ Electron Microscopy ◽  
Beam Sputtering ◽  
The Subject

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.

Modifications of a JEOL 2000EX TEM for insSitu surface studies

1993 ◽  
Vol 51 ◽  
pp. 640-641
Author(s):  
Michael T. Marshall ◽  
Xianghong Tong ◽  
J. Murray Gibson
Keyword(s):  
Electron Diffraction ◽  
Surface Science ◽  
Film Growth ◽  
High Vacuum ◽  
High Energy ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Transmission Electron ◽  
Fundamental Insight

We have modified a JEOL 2000EX Transmission Electron Microscope (TEM) to allow in-situ ultra-high vacuum (UHV) surface science experiments as well as transmission electron diffraction and imaging. Our goal is to support research in the areas of in-situ film growth, oxidation, and etching on semiconducter surfaces and, hence, gain fundamental insight of the structural components involved with these processes. The large volume chamber needed for such experiments limits the resolution to about 30 Å, primarily due to electron optics. Figure 1 shows the standard JEOL 2000EX TEM. The UHV chamber in figure 2 replaces the specimen area of the TEM, as shown in figure 3. The chamber is outfitted with Low Energy Electron Diffraction (LEED), Auger Electron Spectroscopy (AES), Residual Gas Analyzer (RGA), gas dosing, and evaporation sources. Reflection Electron Microscopy (REM) is also possible. This instrument is referred to as SHEBA (Surface High-energy Electron Beam Apparatus).The UHV chamber measures 800 mm in diameter and 400 mm in height. JEOL provided adapter flanges for the column.

Experimental Measurement of In-Plane Rolling Nonpneumatic Tire Vibrations Using High-Speed Imaging

2019 ◽  
Vol 47 (3) ◽  
pp. 196-210
Author(s):  
Meghashyam Panyam ◽  
Beshah Ayalew ◽  
Timothy Rhyne ◽  
Steve Cron ◽  
John Adcox
Keyword(s):  
High Speed ◽  
Image Correlation ◽  
Dynamic Mode Decomposition ◽  
Dynamic Mode ◽  
High Speed Imaging ◽  
Correlation Algorithm ◽  
Mode Decomposition ◽  
Series Of Experiments ◽  
Plane Deformations ◽  
Dominant Frequencies

ABSTRACT This article presents a novel experimental technique for measuring in-plane deformations and vibration modes of a rotating nonpneumatic tire subjected to obstacle impacts. The tire was mounted on a modified quarter-car test rig, which was built around one of the drums of a 500-horse power chassis dynamometer at Clemson University's International Center for Automotive Research. A series of experiments were conducted using a high-speed camera to capture the event of the rotating tire coming into contact with a cleat attached to the surface of the drum. The resulting video was processed using a two-dimensional digital image correlation algorithm to obtain in-plane radial and tangential deformation fields of the tire. The dynamic mode decomposition algorithm was implemented on the deformation fields to extract the dominant frequencies that were excited in the tire upon contact with the cleat. It was observed that the deformations and the modal frequencies estimated using this method were within a reasonable range of expected values. In general, the results indicate that the method used in this study can be a useful tool in measuring in-plane deformations of rolling tires without the need for additional sensors and wiring.

A new method for the in situ assay of α-glucosidase activity and inhibitor screening through an enzyme substrate-mediated DNA hybridization chain reaction

2019 ◽  
Vol 43 (24) ◽  
pp. 9458-9465
Author(s):  
Xiquan Yue ◽  
Lihong Su ◽  
Xu Chen ◽  
Junfeng Liu ◽  
Longpo Zheng ◽  
...  
Keyword(s):  
Small Molecule ◽  
Dna Hybridization ◽  
New Method ◽  
Hybridization Chain Reaction ◽  
Chain Reaction ◽  
Inhibitor Screening ◽  
Glucosidase Activity ◽  
Enzyme Substrate ◽  
In Situ Assay

The strategy is based on small molecule-mediated hybridization chain reaction.

scholarly journals Digital Image Correlation for Evaluation of Cracks in Reinforced Concrete Bridge Slabs

2021 ◽  
Vol 6 (7) ◽  
pp. 99
Author(s):  
Christian Overgaard Christensen ◽  
Jacob Wittrup Schmidt ◽  
Philip Skov Halding ◽  
Medha Kapoor ◽  
Per Goltermann
Keyword(s):  
Reinforced Concrete ◽  
Digital Image Correlation ◽  
Crack Initiation ◽  
Laboratory Test ◽  
Digital Image ◽  
Crack Detection ◽  
Image Correlation ◽  
In Situ Tests ◽  
Stop Criterion

In proof-loading of concrete slab bridges, advanced monitoring methods are required for identification of stop criteria. In this study, Two-Dimensional Digital Image Correlation (2D DIC) is investigated as one of the governing measurement methods for crack detection and evaluation. The investigations are deemed to provide valuable information about DIC capabilities under different environmental conditions and to evaluate the capabilities in relation to stop criterion verifications. Three Overturned T-beam (OT) Reinforced Concrete (RC) slabs are used for the assessment. Of these, two are in situ strips (0.55 × 3.6 × 9.0 m) cut from a full-scale OT-slab bridge with a span of 9 m and one is a downscaled slab tested under laboratory conditions (0.37 × 1.7 × 8.4 m). The 2D DIC results includes full-field plots, investigation of the time of crack detection and monitoring of crack widths. Grey-level transformation was used for the in situ tests to ensure sufficient readability and results comparable to the laboratory test. Crack initiation for the laboratory test (with speckle pattern) and in situ tests (plain concrete surface) were detected at intervals of approximately 0.1 mm to 0.3 mm and 0.2 mm to 0.3 mm, respectively. Consequently, the paper evaluates a more qualitative approach to DIC test results, where crack indications and crack detection can be used as a stop criterion. It was furthermore identified that crack initiation was reached at high load levels, implying the importance of a target load.

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