An ellipsometer and a detection method based on the ellipsometer

Abstract

The present invention relates to an ellipsometer and a detection method based on the ellipsometer. An embodiment of the ellipsometer includes: a laser emits laser light, and the laser light is modulated by an acousto-optic modulator and then enters a first converging lens. After the laser beam is focused by the converging lens, the laser beam is collimated into parallel light by the collimator lens and enters the Bessel beam converter; the Bessel beam converter converts the laser beam into a Bessel beam and sends it to the polarizer, and the polarizer exits The linearly polarized Bessel beam passes through the first half mirror and irradiates the object to be detected through the high numerical aperture lens; the laser reflected by the object to be detected passes through the high numerical aperture lens and is reflected by the first half mirror to the The second half-mirror, the laser light enters the analyzer after passing through the second half-mirror, and the laser emitted by the analyzer irradiates the first photosensitive unit; the first photosensitive unit obtains the laser light intensity to determine the ellipsometric parameters information. This embodiment can detect polarization characteristics of different reflection angles and azimuth angles in parallel.

Description

technical field [0001] The invention relates to the technical field of photoelectric detection, in particular to an ellipsometer and a detection method based on the ellipsometer. Background technique [0002] The principle of the ellipsometer is to irradiate a sample with light of a determined polarization state, and to calculate the optical properties of the sample by measuring the polarization state of the reflected light. An ellipsometer is an optical measurement instrument used to probe film thickness, optical constants, and the microstructure of materials. Due to the high measurement accuracy, suitable for ultra-thin films, non-contact with the sample, no damage to the sample, and no need for vacuum, the ellipsometer is an extremely attractive measuring instrument. [0003] Ellipsometer to measure reflectivity R p and reflectance R s The complex ratio of , where R p is the reflectance of P polarized light, R s is the reflectance of S polarized light. R p and R s...

AI Technical Summary

Problems solved by technology

[0004] There are many types of ellipsometers currently on the market. The ellipsometers provided are all constructed separately from the illumination arm, detection arm, and sample platform. Different reflection angles and orientations can be achieved by rotating the angles of the illumination arm and detection arm. Angle scanning, the detection time of this scanning ellipsometer is too long, which is not conducive to the detection of some samples

Patent CN200780022259 discloses a method of simultaneously illuminating polarized light at multiple angles to improve detection efficiency, but no ellipsometers have been found to detect synchronously according to different reflection angles and radial angles

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