Pulse laser-based over-focus scanning optical microscopic imaging device and method

Abstract

The invention provides an over-focus scanning optical microscopic imaging device based on pulse laser, and the device comprises a pulse laser irradiation unit which is used for emitting beam-expanded pulse laser; the semi-transparent and semi-reflecting mirror is used for reflecting the beam-expanded pulse laser to form reflected beam-expanded pulse laser; the focusing lens is used for focusing the reflected beam-expanded pulse laser to form scanning light; the scanning light irradiates a sample placed on a movable sample table and then is reflected to form sample reflected light; the sample reflected light becomes measurement signal light after passing through the focusing lens and the semi-transparent and semi-reflective mirror; and the detection scanning acquisition unit is used for controlling the sample table to move and acquiring image data of the measurement signal light so as to obtain an over-focus scanning optical microscopic image of the sample. The invention further provides an over-focus scanning optical microscopy imaging method based on the pulse laser, the sample scanning speed is increased according to the ultra-short pulse repetition frequency and the high-speed camera response frequency, and then the over-focus scanning optical microscopy measurement speed is increased.

Description

technical field [0001] The present disclosure relates to the technical field of semiconductor laser measurement, and in particular, to a pulsed laser-based overfocus scanning optical microscope imaging device and method. Background technique [0002] With the rapid development of the semiconductor industry, the feature size of the device structure is getting smaller and smaller, and the device structure is becoming more and more complex. To ensure device quality and yield, it is necessary to measure and analyze the three-dimensional feature size of semiconductor devices. Semiconductor device feature sizes are typically on the order of μm to nm. The traditional measurement methods include electron microscope, scanning tunneling microscope and atomic force microscope. These methods can only measure the surface structure, and destructive measures are required for the internal structure. At the same time, the measurement speed of these methods is relatively slow. In recent yea...

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Problems solved by technology

[0004] The TSOM method usually uses continuous light as the measurement light source. In order to obtain a clear image during the scanning measurement process, the sample (or camera, laser wavelength) needs to be in a static state when collecting the image. Therefore, scanning and image collection can only be performed alternately, which greatly reduces the measurement time. speed,

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