Development of a Technique for Sub-nm Measurements of 1-D Motion and its Application to MEMS

Abstract

This thesis examines the development and testing of a new algorithm for measuring rectilinear displacements in Micro Electro Mechanical Systems (MEMS), however the algorithm could easily be applied to other applications. This optical measurement technique is based on cross correlation used in signal matching. The primary objective of this thesis is to develop a system with improved resolution and versatility which can be applied to a wide variety of MEMS chip designs. Experiments testing this new algorithm had a standard deviation in the measurement as low as 0.23 nm (equivalent to less than 1/700 of a pixel). This result is approximately 4.5 times better than previously found in the Dalhousie MEMS lab using existing algorithms. In addition, when the conditions of the measurement were made worse, the new algorithm consistently outperformed the existing algorithm. Further development may be able to yield additional improvements in the measurements.