Fabrication of Uniaxially Aligned Silica Nanogrooves with Sub-5 nm Periodicity on Centimeter-Scale Si Substrate Using Poly(dimethylsiloxane) Stamps

Abstract

The large-area fabrication of aligned nanopatterns with sub-5 nm feature size is crucial for developing nanodevices. Highly ordered nanostructures fabricated through molecular self-assembly exhibit substantial potential for sub-5 nm patterning techniques. Previously, we had reported the fabrication of silica nanogrooves with sub-5 nm periodicity on a Si substrate by using the outermost surfaces of cylindrical surfactant micelles as a template. However, uniaxial alignment of nanogrooves on the entire substrate surface has not yet been achieved. In this study, uniaxially aligned silica nanogrooves were prepared on the entire surface of a Si substrate (2 cm × 2 cm) by utilizing a poly­(dimethylsiloxane) (PDMS) stamp with a striped pattern. The PDMS stamp was placed on the surface of a surfactant thin film precoated on the substrate, although the stamp was not in direct contact with the substrate as in the case of the soft nanoimprint technique. The substrate was then exposed to water vapor, during which cylindrical micelles were aligned in the direction of the guide. Subsequently, by exposing the substrate to an NH3–water vapor mixture, the outermost surfaces of the aligned micelles facing the substrate were replicated with soluble silicate species. The formation of uniaxially aligned nanogrooves on the entire surface of the centimeter-scale substrate was verified by scanning electron microscopy observations and grazing-incidence small-angle X-ray scattering analysis. Thus, herein we provide a simple large-area fabrication method for uniaxially aligned nanopatterns with ultrafine pitch.

Dielectric Elastomers UV-Cured from Poly(dimethylsiloxane) Solution in Vinyl Acetate

“…3 VAc contains 1.0 mol% of 1-hydroxycyclohexyl phenyl ketone as a photoinitiator. 4 The values are assigned to the mechanical properties of UV-cured film after saponification. We obtain homogenous VPDMS solutions in vinyl acetate (VAc) even if the difference of the solubility parameters between PDMS (14.9~15.5 MPa 1/2 ) and VAc (18.4 MPa 1/2 ) is comparatively large [20][21][22].…”

“…Since the two PDMSs are mechanically mixed together just before shape forming and thermal curing, the platinum-catalyzed reaction cannot uniformly occur during curing, resulting in heterogenous mechanical properties of the PDMS product. Nevertheless, PDMSs have been used as a shapable material for nanoimprint stamps, microfluidic chips, electronic skins, wearable sensors, and actuators owing to their transparency, biocompatibility, and flexibility, in addition to their moldability [4][5][6][7][8][9][10]. However, the other characteristics such as hydrophilicity and dielectric permittivity need to be tuned or improved for effective application of PDMS to the appropriate devices [11][12][13].…”

“…A numeral of the solution names means wt % of VAc in each VPDMS solution 3. VAc contains 1.0 mol% of 1-hydroxycyclohexyl phenyl ketone as a photoinitiator 4. The values are assigned to the mechanical properties of UV-cured film after saponification.…”

Interconnection of organic–inorganic hybrid nano-building blocks towards thermally robust mesoporous structures

“…As has been reported, the alignment of micelles is affected by external factors such as the limitation of space. 55 The thin macropore wall (thickness of 20-30 nm) may induced alignment of the F127 micelles and allow subsequent formation of hexagonally ordered mesoporous structures. Hierarchical porous materials with a macropore diameter of approximately 70 nm and 600 nm were also prepared through the same procedure (Fig.…”

Micro-Nano Machining TiO2 Patterns without Residual Layer by Unconventional Imprinting

“…In the field of material micro-nano processing, the patterning technology has attracted more and more attention such as chemical vapor deposition [1], electrochemical machining [2], focused ion beam [3], imprinting [4] and so on. The imprinting method [5][6][7][8] is a new technology, which is famous for its high efficiency, large area and repeatability. However, the high-resolution template is expensive and is easily consumed in the imprinting process.…”