| AVS 58th Annual International Symposium and Exhibition | |
| Helium Ion Microscopy Focus Topic | Tuesday Sessions |
| Session HI-TuP |
| Session: | Aspects of Helium Ion Microscopy Poster Session |
| Presenter: | F.H.M. Faridur Rahman, Carl Zeiss NTS |
| Authors: | F.H.M. Rahman, Carl Zeiss NTS L.A. Stern, Carl Zeiss NTS J.A. Notte, Carl Zeiss NTS |
| Correspondent: | Click to Email |
From the time of its conception, the gas field ion source (GFIS) was operated with a variety of gas species - each considered for some particular virtue that depended on the particular application. However, practical issues such as vibration, cost, and stability prevented the commercial introduction of the GFIS for 50 years. The one gas species that was deemed to be most suitable was helium, and this was recently offered as a commercial product in the form of the ORION helium ion microscope in 2006. Now with several years of continued learning, the neon GFIS is being reconsidered in order to determine its suitability for the GFIS and the applications that it might enable.
The virtues of neon arise from its intermediate mass, one third the mass of gallium, and five times the mass of helium. While the helium probe offers minimal damage under normal imaging dosages (1015 ions/cm2), the neon beam can sputter at much higher yield (typically 10 times the rate of helium – nearly half the yield of gallium). Compared to helium, the neon ions also penetrate less deeply, and produce many fewer sub-surface dislocations per surface sputtering event. For example, with a helium beam normally incident upon aluminum at 30 keV, there are about 1200 vacancies per sputtered atom according to SRIM. Under these same conditions, the neon beam produces just about 212 vacancies per sputtered atom, and these are located much closer to the surface. Also, the distribution of sputtering atoms is more localized to the incident beam location when neon is used. Compared to gallium, neon is expected to offer a much smaller probe size, and permit nanofabrication with much higher fidelity.
Experimental results will be presented to characterize the basic properties of the focused ion beam from our prototype neon GFIS system. Images will be provided to demonstrate our first cross-section milling and imaging characteristics.
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(See supplementary PDF online)