NSLS-II Seminar

Large scale epitaxy is becoming more common for industrial production of energy-related materials and consumer products, such us superconducting tapes, solar panels, and adaptive architectural coatings. An increasingly important aspect, especially for power-oriented products, is reduction of manufacturing costs. This requires better understanding of epi film growth on long-length, flexible and inexpensive substrates. A rich array of structural information about the substrate surface can be derived from a well resolved X-ray reflectivity and grazing incidence measurements. However, the high resolution reflectivity trace can only be obtained with a very flat sample surface profile. Flexible substrates are usually smooth on a micron-scale but microscopically warped by residual stress. A solution is to adaptively deform the substrate by an array of nano-positioners. This requires development of a compact closed-loop linear drive with good environmental stability.
The second half of the talk starts with a brief historic perspective of nano-positioning system development since the inception of nanotechnology in 80’s. The following overview will outline state-of the art industrial nano-positioning solutions, such as linear encoders for production of optical gratings, lithographic equipment and other positioning products. The latest trends in the field will be analyzed based on issued patents and patent applications from leading manufacturers of nano-positioning systems and accessories (Physik Instrumente, Heidenhain-Certo, Newfocus, Optodyne, Freescale Semiconductors, KLA-Tencor) and publications of academic R&D groups (D. Shu APS, Y. Dabin ESRF). Discussion of modern nano-positioning solutions include applications of complex composite piezodrives, fast-responsive feedback controls with feedforward corrections, novel position-sensitive sensors for closed-loop operation. Special attention will be given to displacement sensing and readout solutions, such as laser Doppler e