Fabrication of three-dimensional stamps for embossing techniques by lithographically controlled isotropic wet etching

Abstract

The excellent characteristics that nanoimprint lithography (NIL) shows as a two-dimensional patterning technique, such as resolution and throughput, are shared with its three-dimensional (3D) structuring version. Nevertheless, the potentialities of NIL for 3D structuring remain largely unexplored and unexploited, hindered by the difficulties in the fabrication of high quality masters with throughput suitable for practical purposes. We present a technique that allows production of stamps with tightly controlled three-dimensional profiles in the 10 nm–100 μm scale range. This technique consists of a sequence of lithographic steps alternated with isotropic wet etching processes performed on a quartz substrate. Scanning electron microscopy and atomic force microscopy characterization shows that 3D structures with very accurate shape control and nanometer scale surface roughness can be formed with this method. Quartz stamps have been employed in nanoimprint, hot embossing, or casting processes to shape complex plastic elements. This technique is expected to have many applications in different nanotechnology-related fields such as optics, nanomechanics, microfluidics, and plasmon nano-optics

Nanoimprint Lithography: Methods and Material Requirements

“…[47] Finally, it is also possible to use the focused ion beam (FIB) technique to directly "carve out" the desired mold features, even 3D or gray-scale patterns that are very difficult to fabricate, or would involve multiple steps to obtain, by other lithographic techniques. An example of such a structure fabricated by FIB is shown in Figure 5.…”

One-Step Fabrication of Microchannels with Integrated Three Dimensional Features by Hot Intrusion Embossing

“…In hot embossing and injection moulding, thermoplastics heated near to or above their glass transition temperatures can rapidly conform to template features with excellent fidelity. In these approaches, the hurdle becomes the fabrication of the template, which must be redone for each iteration during the prototyping process [24,25,26,27]. A variation on hot embossing called hot intrusion embossing (or partial embossing) offers a solution to this problem.…”

Complete wetting of curved microscopic channels

“…We observed 17 a clear crossover from a planarlike to a geometry dominated regime near liquid-vapor bulk coexistence characterized by a growth exponent ␤ Ӎ −2, whose position was consistent with theoretical predictions. 18 In this work, we report the growth of liquid films on nonlinear channels produced with advanced lithographic techniques 19,20 in order to pattern extended surface areas ͑ϳ1 cm 2 ͒. The main motivation is to provide a first experimental study of wetting at curved microstructured surfaces, a topic of intense theoretical investigations, lately.…”