High speed e-beam lithography for gold nanoarray fabrication and use in nanotechnology.

Jorge Trasobares,Marc François,François Vaurette,Nicolas Clément,Dominique Vuillaume,Didier Théron,Jean-Louis Codron,Hans Romijn

doi:10.3762/bjnano.5.202

Abstract

E-beam lithography has been used for reliable and versatile fabrication of sub-15 nm single-crystal gold nanoarrays and led to convincing applications in nanotechnology. However, so far this technique was either too slow for centimeter to wafer-scale writing or fast enough with the so-called dot on the fly (DOTF) technique but not optimized for sub-15 nm dots dimension. This prevents use of this technology for some applications and characterization techniques. Here, we show that the DOTF technique can be used without degradation in dots dimension. In addition, we propose two other techniques. The first one is an advanced conventional technique that goes five times faster than the conventional one. The second one relies on sequences defined before writing which enable versatility in e-beam patterns compared to the DOTF technique with same writing speed. By comparing the four different techniques, we evidence the limiting parameters for the writing speed. Wafer-scale fabrication of such arrays with 50 nm pitch allowed XPS analysis of a ferrocenylalkyl thiol self-assembled monolayer coated gold nanoarray.

Highlights

Well-ordered arrays of nanoparticles are already showing exciting applications in nanotechnology, including materials science [1,2,3,4,5], electronics [6,7,8,9,10], biology [11,12,13,14] and information technology [14,15]
Gold nanoarrays with an ohmic contact to an highly doped silicon substrate fabricated by e-beam lithography have been proposed as a novel technique for molecular electronics study [1,4,8]
Chemical characterization of the grafted molecules on these gold NPs could not be achieved because of the small patterned area limited by the e-beam writing time

Summary

Introduction

Well-ordered arrays of nanoparticles are already showing exciting applications in nanotechnology, including materials science [1,2,3,4,5], electronics [6,7,8,9,10], biology [11,12,13,14] and information technology [14,15]. Fabrication of 1 cm2 nanoarray of 10 nm gold NPs with 100 nm pitch requires 4 days of e-beam writing [1]. We demonstrate that gold nanoarrays of sub-15 nm diameter, 50 nm pitch can be successfully fabricated either by the DOTF technique or by a new technique called “sequence method” allowing us XPS characterization of ferrocene-thiolated gold NPs prior molecular electronics study.

Results

Conclusion