Automatic Calibration of High-Performance Metrological Instrumentation

Metrology is a multi-billion dollar industry that is an indispensable part of science and manufacturing. A variety of techniques including interferometric microscopes, scanning electron microscopes (SEM), X-ray, and atomic force microscopes (AFM) are used in X-ray mirror manufacturing. The performance of any tool directly depends on the ability to characterize and tune it. Modulation Transfer Function (MTF) is the most comprehensive characteristic of any tool; however, it is rarely used because of the complexity of its implementation. There are no suitable test samples with the required spatial frequencies or software. The objective of this proposal is to develop and commercialize an automatic, turn-key solution to enable the calibration of top level metrological instrumentation used in the manufacturing of X-ray optical elements as well as in many other areas of metrology and nanosciences. The heart of this project lies in the design and fabrication of ideal test samples based on pseudo- random line widths. The power spectra of such samples are inherently flat. Any deviation of the measured data from the flat spectra characterizes the signature of the instrument over its entire dynamic range. We have successfully used nanofabrication technology to fabricate a variety of test samples; the worlds best resolution of 1.5 nm lines was achieved. The developed technique was applied to optimally focus and verify the super-high resolution of soft x-ray microscopes, and to precisely calibrate the instruments. The best ever resolution of soft x-ray microscopes was achieved when using our test samples. A variety of test samples suitable for the calibration of TEMs, SEMs, AFMs, optical microscopes and interferometers were also developed and fabricated. The fabrication technology has progressed so immensely: test samples with a resolution down to 250 nm demonstrated in the past are now extended to a resolution of 30 nm. All the test samples were measured using metrology instruments. In Phase II, a turnkey solution will be developed: Fabrication technologies based on nanoimprint will be developed to enable inexpensive manufacturing of pseudo-random test samples for each type of instrumentation, fully automatic software will be developed to calibrate a variety of metrological instrumentation; the software will be adjusted and tuned for each kind of instrumentation. The worlds top companies highly valued our results, requesting the test samples and software immediately after they become commercially available. The solution will improve reliability, exclude the "human factor," and simplify and expedite the calibration. This new technology fits perfectly into aBeam's existing line of products, which are used mostly for metrology and nanofabrication.