Towards a scanning probe microscope with multiple and different tips

Towards a scanning probe microscope with multiple and different tips

Scanning Probe Microscopy (SPM) is the “Swiss Army Knife” of nanoscience. The tip of an SPM can be used to measure different magnitudes, including interaction forces, topography, current, capacitance, surface potential, and temperature, among many others. Moreover, it can also be used to manipulate materials at the nanoscale, as it allows depositing metals, growing oxides, and etching all kinds of surfaces. After nearly 30 years improving each of these techniques individually, now it is the time to combine them to carry out advanced experiments.

In June of 2019, we published a Perspective paper in Nature Electronics entitled “Scanning probe microscopy for advanced nanoelectronics” [1], in which we reviewed the status of this field and proposed multiple setups for advanced nanoelectronic characterization. Among them, the most remarkable is a multiprobe SPM that combines different types of probes to carry out advanced experiments (both fabrication and characterization) simultaneously and under vacuum conditions. We also made multiple comments on the main challenges to solve, such as how to position multiple tips near each other, and how to find the same nanoscale feature under different tips (sequentially). We feel very happy that our paper is attracting attention. Our perspective paper has been mentioned in the Metrology Report of the 2020 International Roadmap for Devices and Systems (IRDS) [2]; given the importance that this report has for the community working on nanoelectronics, this is a very important recognition for us.

The field of advanced nanoelectronic characterization using SPM is growing fast. On December 10th I had the opportunity to co-chair the 2020 NanoScientific Symposium China (https://live.parksystems.com/nssc2020/), and I happily saw that more and more people are getting interested in this family of techniques: the number of persons registered (560) was the highest compared to the previous eight editions. We interviewed one of the co-inventors of conductive atomic force microscopy [3-4] (Prof. Sean Joseph O’Shea), enjoyed seven invited talks, and hosted one roundtable discussion with expert scientists in the field. Most of the content was recorded and it can be viewed free of charge on this website:

https://live.parksystems.com/nssc2020/symposium-videos/

Overall, SPM is a very advanced tool for nanoelectronic characterization, and everything indicates that it will gain more and more importance in the next years, due to its constant improvement and the growing need for high spatial resolution. But the key revolution will come when we are able to combine multiple SPM techniques to fabricate and characterize nanostructures in situ under a vacuum atmosphere [1].

References

[1]   Hui, F., Lanza, M.*, “Scanning probe microscopy for advanced nanoelectronics”, Nature Electronics 2, 221-229 (2019).

[2]   International Roadmap for Devices and Systems (IRDS, 2020); https://irds.ieee.org/editions/2020

[3]   Murrell, M.P. et al. “Spatially resolved electrical measurements of SiO2 gate oxides using atomic force microscopy”, Appl. Phys. Lett. 62, 786–788 (1993).

[4]   Lanza, M. “Conductive Atomic Force Microscopy: Applications in Nanomaterials”, Publisher: Wiley-VCH, ISBN: 978-3-527-34091-0, August 2017.