Automated quality control for microtechnology components using a depth from focus approach

This paper describes an optical approach to verifying the geometric accuracy of object surfaces structured by an excimer laser. Due to the restricted space in the excimer laser system, a passive optical approach is chosen to be integrated in the system. Different optical techniques are compared. Their advantages and disadvantages for the use of integrating them in a laser system are discussed. The depth from focus approach is presented to create 3D models of surfaces structured by a laser and experimental results are shown. A proposal is given for implementing a runtime control loop for the laser system