Development Of A Snapshot Muller Matrix Ellipsometer

With the development of integrated circuit,panel display,solar cells and other industries,the machining precision is improving,and the critical dimension of the device is decreasing to the nanometer level.The three-dimensional size,film thickness,physical and optical properties of the material of the nano device have a great impact on the performance of the device.Therefore,accurate,rapid and nondestructive testing of these parameters is of great significance to improve the performance of the device.The existing high-precision measurement methods,such as scanning electron microscope,are extremely inefficient,cumbersome and destructive,which are difficult to meet the measurement needs of nanostructures;the traditional time modulated ellipsometer can complete the nondestructive and accurate detection task,but it is time-consuming.The snapshot Mueller matrix ellipsometer solves the Mueller matrix of the sample based on the spectral modulation.It does not need to rotate any device.The measurement time is fast and it is not disturbed by the motion of the device.It is a potential solution to this problem.This paper focuses on the development of the snapshot Mueller matrix ellipsometer,The prime contents and innovations include:The system model of the snapshot Mueller matrix ellipsometer is established,and two key problems are solved: the determination of the system matrix and the recovery of the real frequency coefficient and the virtual frequency coefficient from the measured spectrum.The system optimization index based on the measurement error analysis of snapshot Mueller matrix ellipsometer and the optimization design method of thickness ratio of phase retarder are proposed.The system model including phase delay error and azimuth error is established,and the system model calibration and error correction method considering multi error coupling is proposed,which can accurately calibrate the instrument system error and greatly improve the measurement accuracy of Mueller matrixThe design criteria of the snapshot Mueller matrix ellipsometer are proposed,and the selection and design of the key components are completed.A prototype of the snapshot Mueller matrix ellipsometer is built,and the system error of the instrument is calibrated.The preliminary measurement experiment of the prototype is carried out.The measurement speed of the instrument can reach millisecond level,and the maximum measurement error is about 5%.Finally,the source of measurement error is analyzed,and the improvement scheme is proposed.This paper focuses on the development of the snapshot Mueller matrix ellipsometer,establishes the system model and simulation method of the instrument,mainly researches the correction method of the retardance error and azimuth error,and studies the method of reducing the influence of random error by optimizing the thickness ratio of the phase retarder,and develops a snapshot Mueller matrix ellipsometer with the measurement speed of millisecond The principle prototype of ellipsometer provides a potential solution for the measurement of many parameters in IC,panel display,solar cells and other industries.