Sub-10 nm writing: focused electron beam-induced deposition in perspective

Abstract

Over the past decade, focused electron beaminduced deposition has become a mature necessary part of the tool box engineers and scientists. This review presents the current state of the art in sub-10 nm focused electron beam deposition and describes the dominant mechanisms that have been found so far for this regime. Several questions regarding patterning at the highest resolution are addressed. What do our findings mean for using sub-10 nm focused electron beam deposition for industrial applications? And which fundamental issues remain to be solved? The overview shows that low-energy secondary electrons dominate the deposition process. As a result, the highest obtainable spatial resolution (averaged over many deposits) is limited by the mean free path of those electrons. Therefore, the only route to improve the resolution beyond the current appears to be using complexes that are sensitive to the high-energy electrons in the incident beam, rather than to the secondaries. Focused electron beam-induced deposition is compared to related techniques. It is on par with resist-based sub-10 nm electron beam lithography, showing similar spatial resolutions at similar electron doses. Regarding ion beam lithography, there are several distinguishing issues. Sub-10 nm writing has yet to be demonstrated for ion deposition, and although the deposition rate is relatively low when writing with electrons, electrons do not induce damage to the sample. The latter is a crucial advantage for focused electron beam-induced deposition. Finally, the main challenges regarding the applicability of sub-10 nm focused electron beam-induced deposition are discussed.

Simulation-Guided 3D Nanomanufacturing via Focused Electron Beam Induced Deposition

“…A fraction of the energy loss (f) leads to secondary electron generation according to (1) where n SE is the number of secondary electrons (SE) created, ε is the energy required to create a secondary electron, and Δs is the path length of the electron trajectory that intersects the specific "B" voxel. Data for f is unavailable for the deposited material composition PtC 5 , so f was arbitrarily set to equal to 1 and ε = 73 eV was calculated from atomic values available for Pt (ε = 30 eV) and C (ε = 80 eV), using atomic averaging from Lin et al 28 Conveniently, these values recovered the experimentally measured SE yield of 0.1, which provided an additional calibration between simulations and experiments.…”

Electron-Induced Surface Reactions of η3-Allyl Ruthenium Tricarbonyl Bromide [(η3-C3H5)Ru(CO)3Br]: Contrasting the Behavior of Different Ligands

“…3,4 To gain more fundamental insights into the EBID process, we have employed an ultrahigh vacuum (UHV) surface science approach to study the reactions of EBID precursors under electron irradiation. In contrast to traditional EBID studies, the UHV surface science approach examines the effects of electron irradiation on nanometer-thick films of precursor molecules adsorbed onto chemically inert substrates at low temperatures.…”

Thermal decomposition of fullerene nanowhiskers protected by amorphous carbon mask

“…Since the SEs are important to the EBID and IBID, the resolution of the a C deposition is a bit larger than the SE image resolution15. With some special techniques, sub 10 nm patterns have been obtained by EBID17343536. Typical resolution of electron beam induced deposition with a 2 nm primary beam is about 15~20 nm measured by experiments and Monte Carlo simulation37.…”