| AVS 66th International Symposium & Exhibition | |
| Nanometer-scale Science and Technology Division | Thursday Sessions |
| Session NS-ThP |
| Session: | Nanometer-scale Science and Technology Poster Session |
| Presenter: | Umberto Celano, IMEC, Belgium |
| Authors: | U. Celano, IMEC, Belgium X. Hu, University of California-Merced L. Wouters, IMEC, Belgium K. Paredis, IMEC, Belgium T. Hatschel, IMEC, Belgium P.A.W. van der Heide, IMEC, Belgium A. Martini, University of California-Merced |
| Correspondent: | Click to Email |
The ability of contact-mode atomic force microscopy (AFM) to remove material while scanning has repeatedly been used for surface modification and small-scale tip-induced nanofabrication.[1] In the simplest form, the physical removal of material can be achieved by scanning the nanosized probe against the surface at high enough pressure.[2] More recently, tomographic capability has been explored for various electrical AFM modes by leveraging the same concept and alternating tip-induced removal and probing, in what is often referred to as Scalpel AFM.[3] Here, high-pressure AFM scans (i.e., high load force) are used for a controlled material removal and alternated with conventional contact-mode scans (i.e., standard load force). The alternation of scanning conditions delivers a slice-and-view methodology that generates three-dimensional (3D) datasets, with nm-precision in depth. This method has found wide application in the analysis of ultra-scaled nanoelectronics, where 3D architectures are currently dominating and the probing of confined volumes is mandatory.[4] However, for complex nanostructures such as integrated electronic devices, a detailed comprehension of the tip-sample interaction it’s required for the precise control of the removal process in heterogenous materials. In this work, we combine experimental AFM data with molecular dynamics (MD) simulations that study the fundamentals of high-pressure tip-induced material removal for heterogenous nanostructures. Metal-oxide nanopillars (80 -120 nm diameter) embedded in SiO2 are experimentally probed using high pressure sliding contacts (i.e., diamond probes). We select a regime whereby tens of nm3 are removed targeting a controllable removal rate below 3 nm/scan. The impact of the tip-sample interaction inside the worn regions is investigated in order to generate understanding on the physical wear mechanisms. The experimental results are compared with MD simulations that allow us to study the removal processes as a function of different parameters of the AFM scan, including removal rate and the quality of the machined area. As such, this work paves the way for the development of accurate models to improve the quality of tip-induced material removal in complex nanostructures, with great scientific and technological interest for tomographic probing using AFM.
References
[1] A.A. Tseng, Small. 7 (2011), 3409–3427.
[2] A. A. Tseng, et al., J. Vac. Sci. Technol. B, (2005), 23, 877.
[3] U. Celano, et al., Nano Lett., (2015), 15, 7970–5.
[4] W. Vandervorst, et al., Mater. Sci. Semicond. Process., (2017), 62, 31.