Novel x-ray interferometers for length metrology

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Positioning and measuring with sub-nanometre accuracy are fundamental in the development of modern semiconductor and quantum-based devices where device performance depends heavily on the nanoscale dimensions. To meet this challenge, the lattice parameter of silicon has been formally adopted as the basis of a length scale for nano-metrology. One method for implementing this is x-ray interferometry; a ruler or positioning system stage for nanometrology with subatomic accuracy. The aim of the project is to design and manufacture efficiently x-ray interferometers suitable for a range of dimensional nanometrology applications including ultra-precision positioning and characterisation of nanoscale displacement sensors that will support manufacturing of micro-electronics and quantum devices.The projectThe design of the x-ray interferometer will be based around finite element modelling of ultra high accuracy flexures stages that can be machined from silicon with the model being used as basis for a digital twin. The manufacture of X-ray interferometers is very challenging requiring expertise in machining of brittle materials, high aspect ratio structures and minimisation of surface damage from the machining process. Optimisation of machining parameters, testing the materials and mechanical properties of the machined components along with modelling the behaviour of these components with varying geometries and properties, is key for an agile, efficient and fit-for purpose manufacturing. Objectives:1. Review state-of-art of flexures' design and manufacturing considering Si based substrates.2. Develop prototype analytical and FEM flexure model (flexure virtual twin), derive machining tolerances and validate the flexure movement assumptions experimentally for a simple case.3. Define key manufacturing performance and develop manufacturing strategies of the flexure.4. Manufacture prototype flexure and evaluate the required performance in typical X-ray interferometer set-up.