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!
Turbomachine expander offers efficient, safe strategy for heating, cooling
25.02.2020 | Purdue University
New graphene-based metasurface capable of independent amplitude and phase control of light
20.02.2020 | The Korea Advanced Institute of Science and Technology (KAIST)
Researchers at the University of Bayreuth have discovered an unusual material: When cooled down to two degrees Celsius, its crystal structure and electronic properties change abruptly and significantly. In this new state, the distances between iron atoms can be tailored with the help of light beams. This opens up intriguing possibilities for application in the field of information technology. The scientists have presented their discovery in the journal "Angewandte Chemie - International Edition". The new findings are the result of close cooperation with partnering facilities in Augsburg, Dresden, Hamburg, and Moscow.
The material is an unusual form of iron oxide with the formula Fe₅O₆. The researchers produced it at a pressure of 15 gigapascals in a high-pressure laboratory...
Study by Mainz physicists indicates that the next generation of neutrino experiments may well find the answer to one of the most pressing issues in neutrino physics
Among the most exciting challenges in modern physics is the identification of the neutrino mass ordering. Physicists from the Cluster of Excellence PRISMA+ at...
Fraunhofer researchers are investigating the potential of microimplants to stimulate nerve cells and treat chronic conditions like asthma, diabetes, or Parkinson’s disease. Find out what makes this form of treatment so appealing and which challenges the researchers still have to master.
A study by the Robert Koch Institute has found that one in four women will suffer from weak bladders at some point in their lives. Treatments of this condition...
The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.
Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...
Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.
Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...
12.02.2020 | Event News
16.01.2020 | Event News
15.01.2020 | Event News
25.02.2020 | Power and Electrical Engineering
25.02.2020 | Earth Sciences
25.02.2020 | Life Sciences