Device and method for measuring surface contours of micro-nano devices based on optical frequency comb

Abstract

A device for measuring the surface contour of a micro-nano device based on an optical frequency comb, including an optical frequency comb used as a measurement light source to output a wide-spectrum pulse; a pulse processing module used to pre-process the wide-spectrum pulse output by the optical frequency comb Add chirp and spectrum segmentation to process wide-spectrum pulses into a series of narrow-spectrum sub-pulses; half-mirrors are used to divide narrow-spectrum sub-pulses into reference light and signal light; diffraction elements are used to diffract signal light and convert The spectral distribution is converted into spatial distribution; the signal light detector is used to collect the signal light reflected by the sample to be measured and passed through the diffraction element and the half mirror. The measurement can be completed by using a single-pixel camera, which reduces the requirements on the detector pixels. The lateral resolution of profile measurement can be improved by increasing the number of sub-pulses, increasing the pulse repetition frequency and adjusting the translation speed of the device under test. The measurement speed is fast, and it can be used for surface profile measurement of micro-nano devices on the production line, meeting the requirements of high-throughput measurement.

Description

technical field [0001] The invention relates to the technical field of micro-nano profile measurement, in particular to a device and method for measuring the surface profile of a micro-nano device based on an optical frequency comb. Background technique [0002] Micro-nano device surface profile measurement technology has a wide range of applications in integrated circuits, MEMS devices and other fields. With the rapid development of microelectronics manufacturing technology and processing technology, the production efficiency of micro-nano devices is getting higher and higher, the structure is more and more complex, and the feature size is getting smaller and smaller, which requires high-resolution and rapid measurement of the surface profile of micro-nano devices presented new challenges. [0003] Among the traditional measurement methods, the contact measurement method has extremely high measurement accuracy and lateral resolution, but this type of method requires point-...

AI Technical Summary

Problems solved by technology

[0005] (1) The traditional probe-type measurement method is to achieve contour measurement by point-by-point scanning. White light interferometry requires high-precision focusing, and optical comb array measurement requires scanning repetition frequency. The above methods take a long time to measure and cannot meet the requirements of micro High-throughput measurement requirements on nano-device production lines

[0006] (2) The lateral resolution of the white light interferometry method is limited by the optical diffraction limit and the numerical aperture of the objective lens, and the lateral resolution of the area array measurement method is limited by the pixels of the camera, which cannot cope with the smaller and smaller feature sizes of micro-nano devices

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