In the world of minute particles the first thing you need is… superclean shoes! That’s why a visit to the Nano and Microsystems Technology Lab begins with a shoe cleaning machine and shoe covers, a lab coat, gloves and a mob cap. When you research miniature objects, you must work in a “cleanroom”, which means there can be no dirt or dust particles floating around in the air. But how do you look at things which are not visible to the naked eye?
Dr. Andras Kovacs has been teaching and researching at the Faculty of Mechanical and Medical Engineering at Furtwangen University for about 30 years. He explains his enthusiasm for his area of expertise so vividly, that the words “see”, “know” and “image” take on a completely new meaning. That, for example, surfaces the size of a handball court can fit into a body the size of a sugar cube, as long as they are porous enough and the pores are small enough. That several million transistors can fit on a chip the size of a fingernail. That the smallest components for electronic devices are baked in a high temperature oven, etched with acid or exposed like a photograph. “The development of miniaturisation means that electronic systems are becoming ever smaller and more complex, ” says Dr. Kovacs. “So the components for them also have to become smaller and be able to do more and more. ”
Such multi-tasking components are not only built into practical everyday tools such as smartphones – the fingerprint sensor comes to mind. In microelectronics an intelligent component must absorb information through a sensor, evaluate the signal and be able to react. And, of course, be tiny too. These very small “machines” are also needed in medical technology. Today it is already possible to take photographs in a stomach or within a vein, and the goal for the near future is to be able to send “medicine ferries” through the human body with miniature transmitters and receivers, minute electronics to evaluate the data, on board. There appears to be no end to the possibilities of these tiny things being researched at HFU. The secret to the production of such small components is in the application of wafer thin layers on a substrate – at HFU silicon is used. So that they can carry information, the layers are structured and then undergo just about every chemical process found in the dictionary. One of many facilities of the lab is a three-piece “cluster facility”, in which, for example, various oxide layers are deposited on “nanometer-layered” components, atomic layer by atomic layer. (A nanometer is one billionth of a meter, so really, really tiny.) Various gas pipes lead into the complicated structure, winding round the many filter systems which provide clean air to the lab.
If you didn’t already have the feeling that this is all like something out of science fiction, when you reach the second room of the lab you feel like you are literally on another planet. Here the windows are all covered with plastic film and special lamps flood the room in a yolk-yellow light. In this special atmosphere, the components which have been produced are processed, structured and measured using photolithography. The device, which can scan surfaces a billionth of a meter in size, resembles in principle a record player where a needle moves across the grooves of the record. Only, with a needle which is too small to see. On a record which is too small to see. Dr. Kovacs also shows me some of his colleagues‘ work – what looks like three meters of technology, a table on wheels covered in apparatus, lots of cables, monitors, microscope slides and a large microscope. “And the membrane we’re working on is at the bottom of all that, ” points out Kovacs, and laughs. Because you guessed it – it is too small to see.
Our "Labs in Focus" series opens the doors of the many exciting labs at HFU to show the diverse areas of research available to our young scientists. The articles, which will be published in no particular order, can be read on the HFU Research Blog.