Optical nanolithography using a scanning near-field probe with an integrated light source

James W Kingsley,David G Lidzey,Graham J Leggett,Ali M Adawi,Sumon K Ray

doi:10.1063/1.3032912

James W Kingsley, David G Lidzey + Show 3 more

Open Access

https://doi.org/10.1063/1.3032912

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Journal: Applied Physics Letters	Publication Date: Nov 24, 2008
Citations: 32	License type: other-oa

Affiliation: University of Sheffield

Abstract

An ultracompact near-field optical probe is described that is based on a single, integrated assembly consisting of a gallium nitride (GaN) light-emitting diode (LED), a microlens, and a cantilever assembly containing a hollow pyramidal probe with a subwavelength aperture at its apex. The LED emits ultraviolet light and may be used as a light source for near-field photolithographic exposure. Using this simple device compatible with many commercial atomic force microscope systems, it is possible to form nanostructures in photoresist with a resolution of 35 nm, corresponding to λ/10.

Highlights

Scanning near-field optical microscopySNOMcan be used to image1–5 and pattern6–11 surfaces with a resolution significantly better than conventional far-field optical techniques and is often used to study systems in which the characteristic length scale of interest is below the optical resolution limit of standard or confocal microscopes
While there are several different ways to implement SNOM, cantilever based designs offer many advantages as their construction is similar to regular atomic force microscopes
A laser and segmented photodiode monitors the deflection of the cantilever as it moves across the surface providing feedback to the piezostage such that a constant force can be appliedfor a review of SNOM systems, see Hecht et al.1͒

Summary

Introduction

Scanning near-field optical microscopySNOMcan be used to image1–5 and pattern6–11 surfaces with a resolution significantly better than conventional far-field optical techniques and is often used to study systems in which the characteristic length scale of interest is below the optical resolution limit of standard or confocal microscopes. Optical nanolithography using a scanning near-field probe with an integrated light source The major difference between a cantilever based SNOM system and a standard atomic force microscopeAFMis that an optical path is provided for a second laser beam to illuminate the aperture, and, in the case of imaging, to collect the light emitted or scattered from the tip/sample.

Results

Conclusion