QuMat seminar
2024-12-11, 16:00 – BBG 7.12Electromigration, from pain to gainSpeaker: Alejandro Silhanek – University of Liege Host: Matthieu Verstraete |
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Abstract
Electromigration is the displacement of ions in a metal resulting from the momentum transfer between conducting electrons and diffusing atoms. Although already investigated more than 100 years ago, it became a major problem only when the severe operation conditions of integrated circuits (IC) made it apparent in the late 1960s. Electromigration remains a major concern due to the continuous striving for miniaturization, the use of flexible substrates, and 3D integration of IC, the negative perception of this phenomenon has progressively changed during the last decades. The scientific community first understood the physical mechanisms involved in the process, learnt to mitigate the wearout problem and more recently started to master it. Nowadays, controlled electromigration can be regarded as a appealing tool for modifying the physical properties of micro and nanoscale materials with single atom resolution and with a high degree of flexibility.
In this lecture, we will present a comprehensive overview of the evolution of electromigration from a device failure mechanism to a nanofabrication tool. We will briefly review the historical evolution of the topic, discuss the physical mechanisms and some material aspects, propose a method to efficiently and safely control its rate, and finish with some recent applications to the study of superconducting circuitry. The proposed postprocessing technique of controlled electromigration is particularly appealing in view of its simplicity, robustness and applicability to a large diversity of materials.
Figure: High current density in a narrow constriction produces local heating which in turn thermally activate the directional displacement of oxygen atoms
Biography
Alejandro Silhanek is head of the group Experimental Physics of Nanostructured Materials at the University of Liège, Belgium. He is Professor at the Physics Department since 2011. He has obtained his Ph.D. at the Instituto Balseiro (Bariloche, Argentina) in 2001, followed by two postdoctoral experiences at the KULeuven (Belgium) and Los Alamos National Laboratory (USA). He has more than 200 scientific publications in a large diversity of domains in mesoscopic physics and nanoscience, including magnetism, superconductivity, metamaterials, and quantum transport. More information on our website http://www.mate.ulg.ac.be/