Phase-tilting and rotation interferometry for dynamic optical measurement

In this study, a phase-tilt-rotation iteration algorithm is proposed to realize the phase interferometry measurement of a wafer supported by an air flotation tray with random phase tilt-shifting and rotation vibration. The phase distribution and tilt-shifting values are retrieved by the four-step iteration method, while the rotation values are extracted by the amplified phase distribution and low-frequency morphological characteristics acquired by the spatial carrier interferometry method, with the iterative closest point algorithm. Accuracy phase distribution can be achieved by alternately optimizing the above two processes. The simulation and experiment are carried out to demonstrate the high performance of the proposed method. The results show that it works well with the vibration of random tilt-shifting and rotation on traditional interferometers without additional optical structures.