Calibration Charts and Test Targets

Calibration charts and test targets are used to measure resolution, calibrate magnification and align X-ray, UV and electron microscopes. Charts are fabricated by electron-beam lithography to customer specification. Available structures include Siemens stars, gratings, slits and slit pairs, pinholes, apertures and random hole arrays.

Material and thickness are chosen for the intended operating energy, either for maximum absorption or, where required, for a defined phase shift of the wavefront. Customer artwork supplied as a simple bitmap (BMP) file can be used directly for electron-beam exposure, so logos or any other structures can be included on the chart.

Diffusers and random hole arrays

Random hole arrays can be supplied on their own or as part of a chart, for use as diffusers in coherent diffraction imaging experiments. Diffusers and phase randomisers are made with tungsten thickness selected for the required phase shift at the operating energy.

Custom chart examples

Charts can combine standard test objects with customer-supplied patterns, or be exposed entirely from a customer design. In the examples shown, both charts were fabricated in 1.5 µm tungsten with features below 100 nm. One combined an institute logo with low-, medium- and high-resolution Siemens stars and concentric circles; the other was exposed exactly as supplied by the customer.

For X-ray focusing optics, see Zone Plates and Gratings.

Ordering

Contact us to discuss your requirements or for more information.