In order to perform a picometre precision position measurement over small ranges, capacitive sensing can be a good option. Positioning and alignment of the sensor relative to the measured object is however rather critical. A mechanism to reposition the sensor-electrode is therefore required. The stability of the final measurement may however not be compromised.
In wafer scanners - the machines that define the details of electronic chips - there is a need for highly accurate deformation measurements of the machine components during the chip manufacturing process. This thesis develops an estimation methodology, based on shape fitting principles, that aims at a low estimation error and addresses the specific requirements related to one of the components of a wafer scanner, the wafer chuck.