Novel 6DOF integrated direct drive moving large objects with small vertical dimensions through nanometre spaces
Direct drives incapable of raising objects with nanometre-accuracy above large areas
Direct drives can position objects with high speed and precision, backlash-free and without any intervening gears or coupling. One of their uses is in semiconductor manufacture, for instance the manouevring of reticles. A positioning stage is usually part of the equipment for measuring and structuring substrates, wafers, reticles and the like. The slider of this stage moves objects with extreme accuracy on one plane. In production, this already happens with an accuracy of less than 10 nanometres.
But the manufacturing is carried out on different levels. Here an example is the structuring of wafer layers. Such layers are often as thin as a few nanometres; an entire wafer may be between 0.7 and 0.9 mm thick. Presently available systems of wafer measurement only achieve the extremely low level of measurement uncertainty over a mere few square millimetres. Across their full area, for whole wafers with diameter 150 to 300 mm the typical measurement uncertainty is only in the ± 0.5 to ± 1 micrometre range.
Solution to the problem: an integrated 6DoF direct drive with pneumatic gravity compensators for the lifting
In joint work with SIOS Meßtechnik GmbH and Ilmenau University of Technology, IMMS has developed a 6-dimensional direct drive with air bearing which can move objects along three spatial axes and freely in space around these axes in an area of travel appropriate to the application: planar diameter of 100 mm, ascent or descent range of 10 mm under active control with nanometre-accuracy. Pneumatic gravity compensation assists the raising and lowering by constantly approximating to zero the power to be supplied by the vertical electromagnetic actuators. As a result there is next to no current flowing in the actuator coils, which means there is no unwanted source of heat in the measuring space to interfere with the necessary precision of measurement.
The principle behind this drive is absolutely new in the field of six-dimensional direct drives and has been applied in no known drive system to date. Investigations have already been carried out into its scalability for other applications with a planar field diameter of 200 mm.
Acronym / Name:INPOS / Integrated planar 6DOF positioning and measurement system
Duration:2017 – 2019
Application:Research institutions and ultra-precision mechanical engineering|Structuring of surfaces| high-precision mechatronic drives| precision drive technology| biotechnology
Research field:Magnetic 6D-direct drives with nanometre precision
Dr.-Ing. Frank Spiller
Interim Head of Mechatronics
frank.spiller(at)imms.de+49 (0) 3677 874 93 61
Dr. Frank Spiller will provide detail on our research on magnetic 6D direct drives with nm precision for the nm measurement and structuring of objects. He supports you with services for the development of mechatronic systems, for simulation, design and test of MEMS as well as for finite element modelling (FEM) and simulation.
The INPOS project has been funded by the Federal Ministry for Economic Affairs and Energy (BMWi) in response to a decision of the German Federal Parliament under the reference ZF408707LT7.