Conference papers

To keep up with Moore's law in future, the critical dimensions of device features must further decrease in size. Thus, the nano-electronics and nano-optics manufacturing is based on the ongoing development of the lithography and encompasses also some unconventional methods. In this context, we use the Nanopositioning and Nanomeasuring Machine (NPMM) to generate features in resist layers by means of Direct Laser Writing (DLW),1 Field Emission Scanning Probe Lithography (FE-SPL)2 and Soft UV-Nanoimprint Lithography (Soft UV-NIL)3 with highest accuracy. The NPMM was collaboratively developed by TU Ilmenau and SIOS Meßtechnik GmbH.4 The tool provides a large positioning volume of 25 mm × 25 mm × 5 mm with a positioning resolution of 0.1 nm and a repeatability of less than 0.3 nm over the full range. Previously a single electron transistor (SET) working at room temperature generated by FE-SPL has been demonstrated.5 However, the throughput is limited because of the serial writing scheme making Tennant's law (At R5 ) valid.6 Here, At is the areal throughput and R the lithographic resolution. Thus, patterning of the whole NPMM positioning area by FE-SPL is very time consuming. In order to address this problem, different strategies and/or combinations are conceivable. In this work a so-called Mix-and-Match lithography is conducted. A fast generation of structures in the sub-micron range is possible by means of DLW. By this, features such as electrical wires, contact patches for bonding or labels are generated in resist. Subsequently, we use FE-SPL in order to define the actual nano-scaled features for quantum or single electron devices. In combination, DLW and FE-SPL are maskless lithography strategies, hence, offering completely novel opportunities for rapid nanoscale prototyping of largescale resist patterns. An explanation of this technique is given in a previous publication.7 Furthermore, after reactive ion etching, the sample can be used as template for Soft UV-NIL, thus resulting in a high-throughput process chain for future quantum and/or single electron devices.

In view of the increasing demands on precision optics, microelectronics and precision mechanics nanoscale structuring processes are of great interest. It is becoming more and more important to apply a large number of structures that are as small as possible to ever larger areas with high reliability and to increase the number of structures per area element (packing density). The straightness and uniformity of these structures, as well as the positioning accuracy during the fabrication of such narrow lines and points are at the center of the increase of the packing density. A further decisive role is played by the development of suitable sensors and tools for the production and measurement of these structures. The development and the combination of a new laser based probe for the measurement and a direct laser writing (DLW) tool for the creation of sub-micro structures forms the core of this topic. The new sensor is based on a confocal measuring principle. A fiber coupling is used to avoid thermal influences. At the same time, the fiber end itself serves as a confocal pinhole. For the process tool, comprehensive investigations of laser and resist parameters are necessary. The first results are shown. These two parts are investigated separately and combined at the end of the work. In order to achieve the necessary positioning accuracy, the tool is integrated into the Nanopositioning and Measurement Machine (NPMM).

The semiconductor industry has been done an incomparable progress during the last 60 years. With the ongoing reduction of the structure size by new fabrication techniques the nanomeasurement systems have also increased their performance [1]. Besides this development the measurement and fabrication of freeform surfaces, aspheric lenses or high aspect ratio structures are still highly challenging. There are different commercial and scientific approaches to measure on freeform surfaces [2, 3, 4, 5].