Using neutral metastable argon atoms and contamination lithography to form nanostructures in silicon, silicon dioxide, and gold

Abstract

This letter describes the fabrication of ∼80 nm structures in silicon, silicon dioxide, and gold substrates by exposing the substrates to a beam of metastable argon atoms in the presence of dilute vapors of trimethylpentaphenyltrisiloxane, the dominant constituent of diffusion pump oil used in these experiments. The atoms release their internal energy upon contacting the siloxanes physisorbed on the surface of the substrate, and this release causes the formation of a carbon-based resist. The atomic beam was patterned by a silicon nitride membrane, and the pattern formed in the resist material was transferred to the substrates by chemical etching. Simultaneous exposure of large areas (44 cm2) was also demonstrated.

Atom Lithography: Fabricating Arrays of Silicon Microstructures Using Self-Assembled Monolayer Resist and Metastable Helium Beam

“…At high doses, further degradation of the hydrocarbon molecules caused fragmentation of the carbon chain, and cross-linking polymerization between adjacent fragmented SAM molecules might occur, giving rise to the formation of a highly resistant carbonaceous layer and leading to a negative pattern [36]. In addition, the contamination resist, which was induced by hydrocarbon molecules remaining on the inner wall of the vacuum chambers, remained a concern [40][41]. When the metastable atoms impacted the surface, they transferred their internal energy to these physisorbed hydrocarbon molecules and induced a polymerization change within the exposed region.…”

“…were optimized further, higher resolution of the patterning onto the silicon substrates could be obtained. Athough the interaction between the outermost surface of the SAM and the irradiation of metstable atoms has been investigated for about ten years [34][35][36][37][38][39][40][41], the detailed change in surface chemistry of the outermost of the SAM molecules under the irradiation of helium atom beam is still difficult to predict and remains to be explored. What we demonstrated in the present study was that both the positive-tone and the negative-tone sensitivity of the SAM were related to largely different dosage of MAB and the length of the alkyl chains of SAM molecule (as illustrated in scheme 1 (IV) and (V)).…”

Nanolithography with metastable neon atoms: Enhanced rate of contamination resist formation for nanostructure fabrication

“…One important area in atom lithography is to investigate the use of atoms to expose or to deposit resist materials that have high resolution and that can withstand etching. [2][3][4][5] In this regard metastable rare gas atoms are particularly attractive as the source for lithography. 4,5 The atoms are inert and do not bind to the substrates.…”

“…[2][3][4][5] In this regard metastable rare gas atoms are particularly attractive as the source for lithography. 4,5 The atoms are inert and do not bind to the substrates. The internal energy of the atoms is delivered directly to the resist, and the atoms may be easily manipulated by lasers for future applications.…”

Evanescent-light guiding of atoms through hollow optical fiber for optically controlled atomic deposition

“…1 In particular, optical control of an atomic beam is fascinating for the creation of nanometric matters. For example, it has been demonstrated to form a pattern of parallel lines with a method of atom optics.…”