Control method of single-rotation compensator spectral ellipsometer system

Abstract

The invention relates to a control method of a single-rotation compensator spectral ellipsometer system. The method comprises the following steps of 1, using a clock circuit to simultaneously output adrive pulse and a trigger pulse, wherein the drive pulse is used for driving a motor, the trigger pulse is used for triggering a spectrometer, and the period of the trigger pulse is the same as the rotation period of the motor; 2, acquiring the time deviation between an output pulse and a trigger pulse of an encoder at a calibration moment, and acquiring an initial azimuth angle of a phase compensator at the calibration moment; 3, acquiring the time deviation between the output pulse and the trigger pulse of the encoder after restarting, and calculating the deviation between the initial azimuth angle of the compensator after restarting and the initial azimuth angle of the compensator at the calibration moment; and 4, compensating the deviation between the initial azimuth angle of the compensator after restarting and the initial azimuth angle of the compensator at the calibration moment into the initial azimuth angle of the compensator at the calibration moment to obtain the initial azimuth angle of the compensator after restarting. According to the invention, the measurement precision is improved, the hardware requirement is reduced, and the equipment cost is saved.

Description

Technical field [0001] The invention relates to the field of detection and measurement, in particular to a control method of a single-rotation compensator spectral ellipsometer system. Background technique [0002] Spectroscopic ellipsometer is a kind of optical film detection equipment, which uses the change of the polarization state of the polarized light on the surface of the sample medium to conduct model analysis to obtain physical information such as sample film thickness, extinction coefficient, and refractive index. Compared with traditional electron microscope (SEM), focused ion beam (F IB) and other measurement methods, the spectroscopic ellipsometer has many advantages such as non-contact, non-destructive, high integration possibility, and simple testing. It has become an important means for online thin film inspection in semiconductor and other industries. [0003] Spectroscopic ellipsometers are currently divided into single rotation modulation type and double rotatio...

AI Technical Summary

Problems solved by technology

[0009] Aiming at the technical problems existing in the prior art, the present invention provides a single-rotation compensator spectral type ellipsometer system control method, which solves the problem of measurement accuracy caused by the unsteady operation of the conventional rotor motor and the performance fluctuation of the encoder, and reduces the The hardware requirement of the ellipsometer system saves the equipment cost

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