On the assessment by grazing-incidence small-angle X-ray scattering of replica quality in polymer gratings fabricated by nanoimprint lithography

Grazing-incidence small-angle X-ray scattering (GISAXS) can be used to characterize the replica quality of polymer gratings prepared by thermal nanoimprint lithography (NIL). Here it is shown using GISAXS experiments that a series of NIL polymer gratings with different line quality present characteristic features that can be associated with the level of defects per line. Both stamps and NIL polymer gratings exhibit characteristic semicircle-like GISAXS patterns. However NIL polymer gratings with defective lines exhibit GISAXS patterns with an excess of diffuse scattering as compared to those of the corresponding stamps. In a first approach, this effect is attributed to a reduction of the effective length of the lines diffracting coherently as the number of defects per line increases.

Download Full-text

Grazing-incidence small-angle X-ray scattering of soft and hard nanofabricated gratings

Journal of Applied Crystallography ◽

10.1107/s0021889812030415 ◽

2012 ◽

Vol 45 (5) ◽

pp. 1038-1045 ◽

Cited By ~ 42

Author(s):

D. R. Rueda ◽

I. Martín-Fabiani ◽

M. Soccio ◽

N. Alayo ◽

F. Pérez-Murano ◽

...

Keyword(s):

Small Angle ◽

Nanoimprint Lithography ◽

Incidence Angle ◽

Critical Length ◽

Grazing Incidence ◽

One Dimensional ◽

X Ray ◽

X Ray Scattering ◽

Characteristic Features ◽

Ray Scattering

Grazing-incidence small-angle X-ray scattering (GISAXS) has been used to structurally characterize model hard and soft gratings of nanotechnological interest. The different gratings exhibit GISAXS patterns with characteristic features that can be associated with their level of order along the direction of periodicity and the length of the lines. Highly ordered gratings, made out of silicon by electron beam lithography, and those nanofabricated on spin-coated polymer films by nanoimprint lithography, exhibit characteristic semicircle-like GISAXS patterns with intensity spots periodically distributed on a semicircle whose radius is related to the incidence angle used. These gratings can be considered as one-dimensional crystalline lattices as provided by computer simulations. Less ordered polymer gratings prepared by the laser-induced periodic surface structuring method exhibit a GISAXS pattern characterized by periodic rod-like scattering maxima whose intensity decreases with increasing horizontal scattering angle. In this case the gratings can be considered as one-dimensional paracrystals. The transition from a rod-like to a semicircle-like GISAXS pattern has been simulated and attributed to the contribution of the form factor by changing the length of the line (ripple). A critical length value for the transition is located at around a few micrometres.

Download Full-text

Grazing-incidence small angle x-ray scattering studies of nanoscale polymer gratings

10.1117/12.2085824 ◽

2015 ◽

Cited By ~ 4

Author(s):

Manolis Doxastakis ◽

Hyo Seon Suh ◽

Xuanxuan Chen ◽

Paulina A. Rincon Delgadillo ◽

Lingshu Wan ◽

...

Keyword(s):

Small Angle ◽

Grazing Incidence ◽

X Ray ◽

X Ray Scattering ◽

Polymer Gratings ◽

Ray Scattering

Download Full-text

Distortion analysis of crystalline and locally quasicrystalline 2D photonic structures with grazing-incidence small-angle X-ray scattering

Journal of Applied Crystallography ◽

10.1107/s1600576719001080 ◽

2019 ◽

Vol 52 (2) ◽

pp. 322-331 ◽

Cited By ~ 2

Author(s):

Mika Pflüger ◽

Victor Soltwisch ◽

Jolly Xavier ◽

Jürgen Probst ◽

Frank Scholze ◽

...

Keyword(s):

Small Angle ◽

Nanoimprint Lithography ◽

High Sensitivity ◽

Grazing Incidence ◽

X Ray ◽

Perfect Lattice ◽

Lattice Design ◽

Photonic Structures ◽

X Ray Scattering ◽

Ray Scattering

In this study, grazing-incidence small-angle X-ray scattering (GISAXS) is used to collect statistical information on dimensional parameters in an area of 20 × 15 mm on photonic structures produced by nanoimprint lithography. The photonic structures are composed of crystalline and locally quasicrystalline two-dimensional patterns with structure sizes between about 100 nm and 10 µm to enable broadband visible light absorption for use in solar-energy harvesting. These first GISAXS measurements on locally quasicrystalline samples demonstrate that GISAXS is capable of showing the locally quasicrystalline nature of the samples while at the same time revealing the long-range periodicity introduced by the lattice design. The scattering is described qualitatively in the framework of the distorted-wave Born approximation using a hierarchical model mirroring the sample design, which consists of a rectangular and locally quasicrystalline supercell that is repeated periodically to fill the whole surface. The nanoimprinted samples are compared with a sample manufactured using electron-beam lithography and the distortions of the periodic and locally quasiperiodic samples are quantified statistically. Owing to the high sensitivity of GISAXS to deviations from the perfect lattice, the misalignment of the crystallographic axes was measured with a resolution of 0.015°, showing distortions of up to ±0.15° in the investigated samples.

Download Full-text