Feedback-controlled electromigration
{{Short description|Electronic experimental technique}}
{{Use dmy dates|date=June 2024}}
Feedback-controlled electromigration (FCE) is an experimental technique to investigate the phenomenon known as electromigration. By controlling the voltage applied as the conductance varies it is possible to keep the voltage at a critical level for electromigration.
Theory
FCE has been shown to be reversible, demonstrating the fact that the electrons are moving rather than thermomigration or sublimation. The migration occurs due to the electronic wind force experienced by the metallic adatom.{{cite journal | author = H.Ishida | title = Driving force for adatom electromigration within mixed Cu/Al overlayers on Al(111) | journal = Journal of Applied Physics | volume = 89 | issue = 9 | pages = 4809–4814 |date=September 2000 | doi = 10.1063/1.1325385 |bibcode = 2001JAP....89.4809R }} The electromigration occurs at a critical power dissipation in the neck of the bridge.{{cite journal | author = D.R. Strachan | title =Clean Electromigrated Nanogaps Imaged by Transmission Electron Microscopy | journal = Nano Letters | volume = 6 | issue =3 | pages =441–444 | year = 2006 | url = http://pubs.acs.org/wls/journals/query/citationFindResults.html?op=findCitation&cit_qjrn=nalefd&vol=6&spn=441&mscid=&submit.x=24&submit.y=9&submit=FIND |display-authors=etal| doi =10.1021/nl052302a | pmid =16522038 | bibcode =2006NanoL...6..441S | url-access =subscription }} This leads to Electromigrated Nanogaps which hold immense potential for sensing applications, exploiting the quantum tunneling effect.{{Cite journal |last1=Raja |first1=Shyamprasad N. |last2=Jain |first2=Saumey |last3=Kipen |first3=Javier |last4=Jaldén |first4=Joakim |last5=Stemme |first5=Göran |last6=Herland |first6=Anna |last7=Niklaus |first7=Frank |date=2024-07-17 |title=Electromigrated Gold Nanogap Tunnel Junction Arrays: Fabrication and Electrical Behavior in Liquid and Gaseous Media |journal=ACS Applied Materials & Interfaces |language=en |volume=16 |issue=28 |pages=37131–37146 |doi=10.1021/acsami.4c03282 |issn=1944-8244 |pmc=11261569 |pmid=38954436}}{{Cite journal |last1=Raja |first1=Shyamprasad N. |last2=Jain |first2=Saumey |last3=Kipen |first3=Javier |last4=Jaldén |first4=Joakim |last5=Stemme |first5=Göran |last6=Herland |first6=Anna |last7=Niklaus |first7=Frank |date=2024-07-01 |title=High-bandwidth low-current measurement system for automated and scalable probing of tunnel junctions in liquids |url=https://pubs.aip.org/rsi/article/95/7/074710/3303945/High-bandwidth-low-current-measurement-system-for |journal=Review of Scientific Instruments |language=en |volume=95 |issue=7 |doi=10.1063/5.0204188 |pmid=39037302 |bibcode=2024RScI...95g4710R |issn=0034-6748|url-access=subscription |doi-access=free }}
Uses
FCE is often used in forming nanogaps in metallic bridges.
Problems
Thermal runaway can occur when the neck is narrower than about 20 nm.{{cite journal | author = M.Mahadevan and R.m. Bradley | title =Simulations and theory of electromigration-induced slit formation in unpassivated single-crystal metal lines | journal = Physical Review B | volume = 59 | issue =16 | pages =11037–11046 | year = 1999 |doi = 10.1103/PhysRevB.59.11037 |bibcode = 1999PhRvB..5911037M }}