Fabrication of nanostructured substrates comprising a plurality of nanostructure gradients on a single substrate

Abstract

The invention relates to a method for producing a nanostructured substrate comprising an array of protruding nanostructures, in particular nano-pilalrs, which method comprises at least the following steps: a) providing a primary substrate; b) depositing at least one layer of a material capable to be removed by means of reactive ion etching (RIE) onto said primary substrate which layer comprises apredetermined gradient of its thickness; c) depositing a nanostructured etching mask onto the graded layer deposited in step b); d) generating protruding structures, in particular nanopillars, in thegraded layer deposited in step b) by means of reactive ion etching (RIE), wherein simultaneously at least 2, preferably 3, predetermined continuous gradients of geometric parameters of the protrudingstructures are generated on the same substrate- More specifically, the geometric parameters are selected from the group comprising the height, diameter and spacing - of the protruding nanostructures.A further aspect of the invention relates to a nanostructured substrate comprising an array of protruding nanostructures obtainable by the method as outlined above. In a preferred embodiment of said nanostructured substrate, each of the protruding nanostructures simultaneously represents an element of 3 continuous gradients of the height, diameter and spacing of said protruding nanostructures.

Description

technical field [0001] Various methods are known in the prior art for forming nanostructures on various substrate surfaces, for example by means of electron beam lithography or various etching techniques. Such nanostructures can be used, for example, to immobilize target groups, such as biomolecules, or to provide antireflective coatings on corresponding substrates. Background technique [0002] In general, antireflective coatings are made of several types of thin layers. However, these antireflection layers are only effective in a limited wavelength range, usually only allow slight variations in the angle of incidence and are very difficult to adjust to the required projection or reflection specifications. Moth-eye-like nanostructures (MOES) exhibit a combination of high transmittance nearly independent of wavelength with very low reflectivity and could solve many of these problems (Morhard, C., Nanolithographie, 1-149 (2010); Brunner et al., Applied Optics 52, 4370-4376 ...

AI Technical Summary

Problems solved by technology

This replacement process is very complex and can lead to various problems in terms of realignment of optical paths, sensor alignment, comparability between different filters, etc.

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