Since 1727, scientists and engineers have used Young’s modulus as a measure of the stiffness of a given material. Defined as the ratio of stress (such as the force per unit area pushing on both ends of a beam) to strain (the amount the beam is deflected), Young’s modulus allows the behavior of a material under load to be calculated.
Young’s modulus predicts the length a wire will stretch under tension or the amount of compression that will buckle a thin film. A standard method to determine this important parameter—a necessity to ensure that measurements of Young’s modulus made at different locations are comparable—has eluded those who design, manufacture and test MEMS devices, particularly in the semiconductor industry.
A team at NIST recently led the effort to develop SEMI Standard MS4-1107, “Test Method for Young’s Modulus Measurements of Thin, Reflecting Films Based on the Frequency of Beams in Resonance.” The new standard applies to thin films (such as those found in MEMS materials) that can be imaged using an optical vibrometer or comparable instrument for non-contact measurements of surface motion. In particular, measurements are obtained from resonating beams—comprised of the thin film layer—that oscillate out-of-plane.
The frequency at which the maximum amplitude (or velocity) of vibration is achieved is a resonance frequency, which is used to calculate the Young’s modulus of the thin film layer. The group also developed a special Web-based “MEMS calculator” (http://www.eeel.nist.gov/812/test-structures/MEMSCalculator.htm) that can be used to determine specific thin film properties from data taken with an optical interferometer.
Knowledge of the Young’s modulus values and the residual strain (using ASTM International Standard E 2245) for thin film layers can lead to calculations of residual stress, which in turn, enable semiconductor manufacturers to develop circuit design strategies, fabrication systems and post-processing methods that could increase fabrication yield by reducing the frequency of failures from electromigration, stress migration and delamination.
Michael E. Newman | EurekAlert!
New test procedure for developing quick-charging lithium-ion batteries
07.12.2017 | Forschungszentrum Jülich
Plug & Play Light Solution for NOx measurement
01.12.2017 | Heraeus Noblelight GmbH
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."
Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...
08.12.2017 | Event News
07.12.2017 | Event News
05.12.2017 | Event News
08.12.2017 | Life Sciences
08.12.2017 | Information Technology
08.12.2017 | Information Technology