Production of minute structures with gold and silicon ions / 840,000 euros from the German Research Foundation and the state of North Rhine-Westphalia
Investigating and developing nanosystems - i.e. structures which are a thousand times smaller than the diameter of a human hair - is something which occupies researchers collaborating from a variety of disciplines at the University of Münster. They now have at their disposal a special new piece of equipment for their research work: it goes by the name of VELION and is being funded by the German Research Foundation and the state of North Rhine-Westphalia to the tune of 840,000 euros. The researchers are benefiting from collaboration with the Raith company in Dortmund, which has developed and produced the nanofabrication instrument and whose specialists are now working together with the Münster researchers in developing the system further.
From the outside, the instrument, located on the ground floor of the Center for Soft Nanoscience (SoN) at Münster University, is just a grey cupboard the size of two wardrobes - but inside there is a lot going on. The centrepiece of the equipment is a focused ion beam and a scanning electron microscope. The ion beam enables structures to be “written” in thin layers - for example, to produce circuits on chips. What is special about the instrument is a special ion source with charged gold and silicon atoms. Compared with equipment using gallium ions, which are the ones normally used, this instrument enables the researchers to structure the material more precisely, generate larger-sized structures and thus fill up for example entire wafers, as used in the semiconductor industry. The process also means that many small points can be arranged side by side and joined up with one another. The microscope simultaneously scans the surface of the materials and creates high-resolution images of the molecular structures in order to monitor the process. This type of instrument is the only one of its kind so far in Germany.
The new system is part of the newly established Münster Nanofabrication Facility at Münster University - a modern nanotechnology centre which houses equipment for nanofabrication and which can be used by researchers working in the fields of Chemistry, Physics, Biology and Medicine, as well as by those from other departments. “The various research groups in the SoN and beyond now have entirely new possibilities,” says Prof. Wolfram Pernice, who in the coming years will be testing the VELION system with his team in order to develop it further. In addition, the specialists from Raith will be coming to Münster University regularly to optimise processes and test the functionality of the system.
Initial projects will see the researchers using the equipment among other things for producing so-called artificial neural networks - in other words, a computing architecture on a chip which imitates the structure of the brain. The equipment automatically finds nanostructures on the surface which need improving and carries out the requisite adjustment with the ion beam. This means that significantly more complex networks can be generated which are made up of many individual components perfectly coordinated with one another. The system is also highly relevant for research into quantum technologies: it enables researchers to produce very small patterns using ions directly adjacent to one another - which is an advantage compared to working with electrons, which leads to charging effects. The new method can also be applied in the field of material physics, because a silicon or gold beam does not damage the surface as much as conventionally applied ions do.
In the Center for Soft Nanoscience, which was inaugurated in November 2018 and has almost 8,000 square metres of floor space, there are twelve interdisciplinary teams using modern nanoanalytical methods in their work. The research groups probe the workings of functional materials and the self-organized structure of synthetic materials with desired functionality.