Extreme ultraviolet interference lithography at the Paul Scherrer Institut

Auzelyté, Vaida

doi:10.1117/1.3116559

Cited by 87 publications

(63 citation statements)

References 70 publications

(73 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Details of the EUV lithography, available at the Swiss Light Source, can be found elsewhere. 15 This technique provides high resolution patterns over large areas and with high throughput. Briefly, a coherent beam with 13.5 nm wavelength is incident on a mask comprising two identical gratings.…”

mentioning

confidence: 99%

Fabrication of sub-10 nm gap arrays over large areas for plasmonic sensors

Siegfried

Ekinci

Solak³

et al. 2011

Applied Physics Letters

View full text Add to dashboard Cite

We report a high-throughput method for the fabrication of metallic nanogap arrays with high-accuracy over large areas. This method, based on shadow evaporation and interference lithography, achieves sub-10 nm gap sizes with a high accuracy of 61.5 nm. Controlled fabrication is demonstrated over mm 2 areas and for periods of 250 nm. Experiments complemented with numerical simulations indicate that the formation of nanogaps is a robust, self-limiting process that can be applied to wafer-scale substrates. Surface-enhanced Raman scattering (SERS) experiments illustrate the potential for plasmonic sensing with an exceptionally low standard-deviation of the SERS signal below 3% and average enhancement factors exceeding 1 Â 10 6 . 1,2 This enhancement phenomenon relies on strongly confined electromagnetic fields generated by localized plasmons on metal nanostructures much smaller than the incident wavelength. 3,4 However, surface enhanced (SE) spectroscopic techniques are not yet routinely used at the industrial level. This is due to poor signal reproducibility, moderate average enhancement factors, and high costs. 5 To increase the signal enhancement, nanogap patterns are currently used: they produce extremely large electromagnetic fields for nano objects separated by a distance below 20 nm. 6 Local enhancement factors up to $10 9 have been reported with a one-dimensional (1D) nanogap pattern, 7 enabling single molecule detection. 8 The fabrication of nanogap arrays has been demonstrated with a variety of techniques. Electron-beam lithography (EBL) is used for direct writing 9 or patterning of shadow masks for angular evaporation. 10,11 With EBL, the pattern can be designed and realized with an exceptional degree of freedom. Due to proximity effects of the electron beam and limitations set by the photoresist liftoff, the resulting metal nanogap dimensions are limited to above roughly 10 nm and a metal layer thickness of below 30 nm. 9,12 The serial writing process of EBL makes this technique unfavorable for the fabrication of large area and low-cost sensors. Other lithography-based techniques have been used, including molecular rulers 13,14 or atomic layer deposition (ALD), 7 as effective methods to tune the nanogap size even below 2 nm. This, however, involves complicated multistep fabrication processes and produces local defects, which are found to cause fluctuations of the surface-enhanced Raman scattering (SERS) enhancement across the sensing area 7 or between different substrates.In this letter, we report the fabrication of homogeneous sub-10 nm gap arrays with high surface densities and over large areas. The fabrication scheme for our nanogap arrays consists of only two stages, lithography and metal layer deposition.In the first step, extreme ultraviolet interference lithography (EUV-IL) is used to provide a 1D line array on the substrate, which is typically float glass or silicon. Details of the EUV lithography, available at the Swiss Light Source, can be found elsewhere. 15 This technique provides high resolu...

show abstract

mentioning

confidence: 99%

Fabrication of sub-10 nm gap arrays over large areas for plasmonic sensors

Siegfried

Ekinci

Solak³

et al. 2011

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…For example, extreme ultraviolet LIL (EUV-IL) has produced feature sizes down to 10 nm. 31 Some nonuniformity within structures was observed, which was due to photoresist connections between adjacent features, especially for sample 1 at locations R ð0;10Þ , R ð10;10Þ , and R ð10;0Þ . These samples could be treated with oxygen plasma after sample development, which would result in a removal of the connections between adjacent nanostructures and individual features with a higher degree of uniformity.…”

Section: Discussionmentioning

confidence: 99%

Large area periodic, systematically changing, multishape nanostructures by laser interference lithography and cell response to these topographies

et al. 2013

View full text Add to dashboard Cite

Hamilton, Douglas W.; and Mittler, Silvia, "Large area periodic, systematically changing, multishape nanostructures by laser interference lithography and cell response to these topographies" (2013 Abstract. The fabrication details to form large area systematically changing multishape nanoscale structures on a chip by laser interference lithography (LIL) are described. The feasibility of fabricating different geometries including dots, ellipses, holes, and elliptical holes in both x-and y-directions on a single substrate is shown by implementing a Lloyd's interferometer. The fabricated structures at different substrate positions with respect to exposure time, exposure angle and associated light intensity profile are analyzed. Experimental details related to the fabrication of symmetric and biaxial periodic nanostructures on photoresist, silicon surfaces, and ion milled glass substrates are presented. Primary rat calvarial osteoblasts were grown on ion-milled glass substrates with nanotopography with a periodicity of 1200 nm. Fluorescent microscopy revealed that cells formed adhesions sites coincident with the nanotopography after 24 h of growth on the substrates. The results suggest that laser LIL is an easy and inexpensive method to fabricate systematically changing nanostructures for cell adhesion studies. The effect of the different periodicities and transition structures can be studied on a single substrate to reduce the number of samples significantly.

show abstract

“…1(c) shows the intensity map of two-beam interference, where a one-dimensional periodic pattern is formed. The pitch of the pattern is given by d ¼ d m =2m, where d m is the pitch of the mask and m is the diffraction order of the interfering beams from the mask [26]. For photoresists, there is a threshold above which the photoresist becomes soluble or cured during the exposure.…”

Section: Theorymentioning

confidence: 99%