Search

In this work we present a UV-Nanoimprint (NIL) process flow based on the combination of a novel fully organic imprint resist and a hybrid stamp for high resolution patterning and low-defect imprinting in the sub-100nm regime. The advantages of this combination are on the one hand the facile removal of the fully organic imprint resist mr-NIL210 with an oxygen plasma even after RIE etching, which makes this imprint resist highly attractive for the structuring of metal films by nanoimprint. On the other hand the resist was specially designed for the use in combination with Polydimethylsiloxane (PDMS) stamps, its negligible propensity to permeate into the stamp material under contact leads to an improved stamp life time compared to the use of common imprint resists. The complete process flow is demonstrated for a wire grid polarizer (WGP) with 200nm period and a structure height of 100nm. Display Omitted Successful integration of the novel organic imprint resist mr-NIL210 in the SCIL processDemonstration of a simplified UV-NIL metal structuring process due to organic resist formulationHigh resolution suitability demonstrated based on a 100nm half-pitch wire grid polarizer on quartz

Nanoimprint lithography offers unique capabilities to create patterns with three dimensional shapes. The challenge issue is therefore very often the method to create the stamp carrying complicated and high resolution pattern geometries in 3D. Especially when the geometry of the desired object exhibits a huge spectrum of spatial dimensions or if the replication has to be done on non-flat surfaces, standard mastering or imprinting techniques fail. By using liquid transfer nanoimprint the typical limitation of coating of non-flat surfaces processes is eliminated. We applied this process scheme on two very extreme topographies by creating anti-reflection textures on a micro lens array and a raw multi crystalline solar cell. The dependence between imprint pressure and deformation is analyzed. The results show that nanoimprint with flexible stamp can be extended to non-flat surface to created new sophisticated optical functionalities.

So far, metal oxide semiconductor field-effect transistors (MOSFETs) have been fabricated using either optical lithography or imprint lithography with an alignment step between the different layers. Here, we report on the new process for the fabrication of top gate MOSFETs where the number of fabrication steps is reduced significantly. The 3D topography of a top gate MOSFET using as primary master is inversely replicated into a flexible mold that is subsequently transferred to the imprint resist layer. By reactive ion etching, this self aligned 3D pattern is transferred into the underlying semiconductor stack creating functional transistor structures. Preliminary electrical characterizations demonstrate fully operational transistor functions.

The high throughput and large area nanostructuring of flexible substrates by continuous roller processes has great potential for future custom applications like wire grid polarizers, antireflection films, or super-hydrophobic surfaces. For each application different material characteristics have to be considered, e.g. refractive index, hydrophobicity, or dry etch stability. Herein, we show experimental results of nanoimprint lithography resist developments focused on inkjetable and photo-curable resists suitable for high throughput production, especially roll-to-roll NIL. The inkjet deposition of the novel materials is demonstrated by the use of different state-of-the-art inkjet printheads at room temperature. A plate-to-plate process on silicon substrates was successfully implemented on a NPS300 nano patterning stepper with previously inkjet dispensed NIL resist. Furthermore, we demonstrate a throughput of 30 m min-1 in a roller NIL process on PET. Dry etching of unstructured thin films on Si wafers was performed, and it was demonstrated that the etch stability in Si is tunable to a value of 3.5:1 by a concise selection of the resist components. The surface roughness of the etched films was measured to be < 2 nm, after etching of around 100 nm of the resist films what is an essential factor for a low line edge roughness. All resists reported herein can be deposited via inkjet dispensing at room temperature, are suitable for continuous high throughput imprinting on flexible substrates, and are applicable in step-wise NIL processes with good etch resistance in dry etch processes.

This paper presents a novel tunable infrared filter applying a subwavelength grating that substitutes the distributed Bragg reflectors (DBRs) in tunable Fabry-Perot (FP) filters to reduce cost and fabrication effort. It consists of uniformly arranged disc resonators which are made of 100 nm thick aluminum at a 200 nm Si3N4 membrane carrier that stands freely after fabrication. The dimensions of the subwavelength structures were optimized based on finite difference time domain (FDTD) analysis. The fabrication sequence consists of silicon MEMS technology steps like deposition and patterning of electrodes and of isolation layers, silicon etching, and wafer bonding, and it includes nano imprint lithography for forming the subwavelength structures at wafer level. The samples have an aperture of 2 mm and are mechanically tuned by electrostatic forces with tuning voltages up to 80 V. They show the typical characteristics of FP filters but with high peak transmittance within a remarkably large wavelength range (T < 50% @ 2.5 μm … 6.5 μm) spanning over 5 interference orders of the optical resonator. The optical performance was measured by Fourier transform infrared spectrometer and compared to the simulation results. It shows a widely good agreement between calculation and measurement.

We report on our development strategy of photo-curable resists for nanoimprint lithography (NIL) based on modularity. Starting with a basic formulation, we address two topics: the integration of fluorinated additives and the enhancement of the dry etching stability. We prove both concepts by the introduction of two different resists derived from the same basic formulation. The viscosity of the novel resist materials was optimized for inkjet dispensing at room temperature (RT). The novel resist materials can be applied either in NIL batch processes or in high-throughput roller processes. Batch-wise imprints were performed on various substrates such as Si or plastics, demonstrating the distinctive application versatility of the novel materials. Dry etching of spincoated thin films on Si wafers was performed, demonstrating an etch stability versus Si of 3.5:1 by using the resist formulation with improved etching stability. Roll-to-roll NIL at high throughput on large areas was performed with web speeds of up to 30 mmin−1 with different stamp materials. We conclude that all resists reported herein can be deposited via inkjet dispensing at RT, are suitable for continuous high-throughput imprinting on flexible substrates, and are applicable in step-wise NIL processes with good etch resistance in dry etch processes.

In this paper, a novel robotic platform is introduced, which is able to support other modular robots during the locomotion or self-repair process to increase efficiency of locomotion, payload and runtime. The robot is able to operate autonomous as a stand-alone robot in a swarm or aggregate into robot organisms. We outline the developmental phases of the final robot generation, including mechanics, electronics and software design.

In the fields of swarm and modular robotics, one of the main challenges is to deploy and coordinate the robots in ways that are useful for solving different tasks. The aim of the research we are presenting is to create a self-organizing deployment and coordination system to improve the assembling phase of a group of robots capable of docking with each other. To achieve the presented goal a new technique, namely the “local oriented potential fields,” is combined with physicomimetics (artificial physics) and the behavioral coordination paradigm. The proposed solution offers a way to create four different types of deployments (square, line, star and tree), providing specific properties during the assembly and the solution of tasks. Simulations with NetLogo are used to prove the validity of the proposed ideas.

In this work we explore several adaptation processesin systems with a high degree of developmental plasticity.It is indicated that such systems are driven by twodifferent forces: adaptation fitness and design goals. The goals, formulated in an invariant way to environmental changes, represent an example of a self-concept, used in developmental processes. This paper gives an example of collective locomotion, introduces four different adaptive mechanisms and finally discuss the self-development of such systems.

One of the main aspects of the ‘SYMBRION’ and ‘REPLICATOR’ projects is that the robots can aggregate to form a multi-robot organism. For this reason the control mechanisms have to be able to control a single robot, a swarm of robots or an aggregated collective organism. To break down the complexity of development and to take the interaction with the environment and other robots into account, bio-inspired and evolutionary concepts are applied. In this paper we describe the underlying software architecture for the projects to enable different controller types, evolution and learning.