Compound shade ultra-distinguish differential confocal measurement method and device

Abstract

The invention discloses a complex color super-resolution differential confocal measurement device, comprising a first super-resolution differential confocal measurement device, a second super-resolution differential confocal measurement device, a dichroic mirror, and a partial chromatic aberration correction objective lens, And, computer device. This device can form two partially overlapping linear measurement areas by using the dispersion characteristics of the ideal focus plane translation by focusing beams of different wavelengths, and obtain two linear measurement areas with bipolar tracking characteristics, which not only expands the measuring range by nearly one time , and realize the alternate tracking measurement of the measurement area; through the independent modulation of multiple super-resolution filters, consistent or inconsistent transverse and axial scanning characteristics can be obtained in the two linear measurement areas according to the application requirements, while retaining the differential and super-resolution While resolving the advantages of the differential confocal measurement technique, the linear range of the measurement setup is significantly extended.

Description

technical field [0001] The invention belongs to the field of ultra-precision measurement, and is an ultra-precise non-contact measuring device for measuring three-dimensional microstructures, microsteps, microgroove line width, depth and surface shape in microstructured optical elements, microstructured mechanical elements, and integrated circuit elements. Measurement methods and devices. Background technique [0002] Confocal scanning measurement technology is one of the important technical means to measure three-dimensional micro-structure, micro-step, micro-groove line width, depth and surface shape in the fields of micro-optics, micro-mechanics and micro-electronics. Its basic idea was proposed by M.Minsky in 1957 and obtained a U.S. patent in 1961. Its basic technical idea is to suppress stray light by introducing a pinhole detector and generate axial tomography capabilities. The reason is that the measurement sensitivity of the axial response signal is not high near t...

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Problems solved by technology

Its basic idea was proposed by M.Minsky in 1957 and obtained a U.S. patent in 1961. Its basic technical idea is to suppress stray light by introducing a pinhole detector and generate axial tomography capabilities. The reason is that the measurement sensitivity of the axial response signal is not high near the quasi-focus area of ​​the measurement surface, so it is only suitable for defocus displacement measurement

[0006] attached figure 2 It is a typical wavelength response curve of the above system, as shown in the figure, its linear measurement interval is AX, and the measurement origin is O1, that is, when the position of the measurement surface moves from A to position X, differential or super-resolution can be effectively performed Differential confocal measurement, however, in this system, the high axial measurement resolution obtained by using a large numerical aperture focusing objective lens is contradictory to the extension of the axial measurement range, that is, the higher the axial resolution, the linearity The smaller the measurement range, this relatively narrow linear measurement range is one of the main obstacles restricting the wider application of existing differential and super-resolution differential confocal measurement techniques

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