|M.Sc Student||Ari Berger|
|Subject||A Novel Approach to Nano Position Control System Design|
towards a 450 mm Wafer Inspection X-Y Stage
|Department||Department of Civil and Environmental Engineering||Supervisor||Professor Emeritus Gutman Per-Olof|
|Full Thesis text|
A fast-settling and robust positioning control system design for point to point movements is considered in this thesis. In the metrology industry, an X-Y stage is used to accurately position a wafer under a probing device, such as x-ray or similar, with an accuracy of tens of nano-meters. Today in the industry, the wafer diameter is facing an enlargement in size and weight, moving from wafers of 300 mm in diameter to 450 mm in diameter. In order to provide higher throughput the total time and steady state error for the move-and-settle motion are to be reduced.
The goal of this thesis is to provide a complete design framework to enhance the performance of the X-Y stage. The framework includes a thorough plant dynamic analysis, giving special attention to non-linear friction, a development of a time-suboptimal trajectory planning with friction compensation, and the design of high order robust linear and non-linear feedback compensator to cope with the plant resonances, reduce vibrations, effect of parameter uncertainties and transition between friction regimes.
The testing and verification of the theoretical work is done on an actual stage. Using a dSPACE? system connected to a PC running Simulink?, also known as ``Rapid-Prototyping'' environment, implementation of digital algorithms is performed.