步进偏差补偿相移算法研究OA

The diameter measurement system for single crystal silicon spheres based on interferometry suffered from step deviation during the phase-shifting process due to control accuracy limitations.The use of existing five-step,seven-step,and other phase-shifting algorithms results in errors that are difficult to ignore,thereby affecting the diameter measurement results.To improve the accuracy and reliability of measurement results,a step deviation compensation phase-shifting algorithm was proposed.According to the principle of the diameter measurement,the errors caused by the five-step and the seven-step phase-shifting algorithms were compared and analyzed.Due to the smaller error caused by the multi-beam approximation,the seven-step phase-shifting algorithm is more consistent with the diameter measurement system than the five-step one.Based on the seven-step phase-shifting algorithm,a step deviation compensation phase-shifting algorithm was constructed.This algorithm reduced the maximum absolute value and standard deviation of the error to 0.32 nm and 0.09 nm in the presence of step deviation.An actual diameter measurement system was built and the diameters were measured.The difference between the diameter measurement result and the nominal value was only 0.57 nm,which verified the effectiveness of the proposed step deviation compensation phase-shifting algorithm.