| AVS 62nd International Symposium & Exhibition | |
| Helium Ion Microscopy Focus Topic | Wednesday Sessions |
| Session HI-WeA |
| Session: | GFIS Based Nanostructuring |
| Presenter: | Chung-Soo Kim, MIT |
| Authors: | C.S. Kim, MIT R.G. Hobbs, MIT V.R. Manfrinato, MIT A. Agarwal, MIT K.K. Berggren, MIT D. Wei, Carl Zeiss NTS |
| Correspondent: | Click to Email |
Scaling the dimensions of materials to the nanoscale creates new opportunities and many applications. Nanomaterials display unique properties relative to their bulk counterparts due to surface/interface effects, quantum confinement/coherence, which have been investigated to understand new materials physics. Applications driven by nanostructures can benefit from their enhanced functionalities by modifying material properties and geometries via ion irradiation. Specifically in nanostructures, ion irradiation with a focused ion beam can play a critical role in modifying properties and geometries locally in those nanostructures. This local modification had already been proven to have applications in quantum optics and circuits by creating localized material modification at the nanoscale in bulk materials via focused helium ion beam (FHIB) irradiation However, local modification may occur in different ways in nanostructures. Therefore, one needs to investigate the effect of FHIB irradiation on nanostructures in order to control local modification in a desirable way and understand new physics.
In this work, we primarily study the interaction of a FHIB and nanostructures with two materials, single crystal silicon and diamond. Our experimental approach using thin vertical membranes fabricated by focused gallium ion beam enabled us to observe ion-nanostructure interaction in 3-dimension by preserving defects by ion irradiation. We have investigated new physical phenomena; (1) strain-induced volume expansion, (2) long-range ion propagation, and (3) material behavior’s transition from a bulk to a small-scale where the size-dependent characteristic exists. We have explained these mechanisms between nanostructure (material, crystal orientation, and geometry) and helium ion (energy and dose). We have also extended our study to focused neon ion beam (FNIB) irradiation. We have investigated and compared the difference of ion-nanostructure interaction between neon and helium.
Furthermore, we have expanded our study to new nanofabrication method by embedding a 3D geometry on nanostructures with the consideration of a geometrical constraint, decided by crystal-to-amorphous boundary.