The project aimed to achieve a +10 pm accuracy for displacement metrology by developing the next generation optical interferometrs. The challenge is an uncertainty reduction of one order of magnitude with respect to the present state of the art.
Dimensional measurements play a crucial role in almost every aspects of modern life, in which the role of ICT (Information and Communication Technologies) nanotechnologies is growing. Today laser interferometers are the essential tool for metrology in semiconductor manufacturing where they are used for pattern placement measurements on photomasks and for position control in wafer scanners. A particularly strong requiremrt is metrology to support the the use of double patterning techniques where the accuracy demands of dimensional measurements are rapidly growing. For mask metrology tools, a reproducibility of about 0.3 nm (3σ) is demanded in 2011. This means interferometer nonlinearities, noise and stability well below 0.1 nm will be necessary.
The project provides a bridge between present state-of-the art of traceable displacement measurements by optical interferometers and future new ways and standards to provide traceability at the atomic scale.