Device and method used for measuring film thickness

Abstract

The invention provides a device and a method used for measuring film thickness. The device comprises a collimating lens, a first half-transmitting half-reflecting mirror, a field lens, a second half-transmitting half-reflecting mirror, a collection optical fibre, a picture sensor, a computer and a beam split unit, wherein the beam split unit is used for carrying out beam split treatment on the light collected by the collection optical fibre so as to obtain light of each wavelength in a separate manner; and the computer is used for obtaining the intensity of the light with different wavelengths so as to obtain the film thickness of an analyte through calculating. The device provided by the invention has the advantages that the beam split unit is used for carrying out beam split treatment on the light collected by the collection optical fibre so as to obtain the light of each wavelength in the separate manner, the spectral range of a sample point of the device used for measuring film thickness is enlarged, and the distinguishability is improved; and furthermore, the quantity and position of the sample points can be controlled in a flexible manner through the position adjustment of an optical fibre probe, so that the flexibility of processing data is improved and the high-precision film thickness measurement is realized.

Description

technical field [0001] The invention relates to the field of film thickness measurement, in particular to a film thickness measurement device and method. Background technique [0002] In the production process of Thin Film Transistor-Liquid Crystal Display (TFT-LCD), it is often necessary to measure semiconductor thin films. The basic structure of the existing film thickness measurement device is as follows: figure 1 As shown, the light source 1 emits a beam of light, which forms a parallel beam through the collimator lens 2, reaches the first half-mirror 3, half of the light reaches the objective lens 4 after reflection, and shines on the sample 5, and the light reflected by the sample 5 passes through the mirror. The cylinder reaches the eyepiece 22, and part of the transmitted light by the second half-mirror 6 at the eyepiece 22 reaches the imaging charge-coupled device (Charge-Coupled Device, CCD) 7 to obtain the image information of the sample 5, while the other part of...

AI Technical Summary

Problems solved by technology

[0011] To sum up, the existing film thickness measurement devices, such as the first device, can only obtain the light intensity of certain wavelengths by light separation due to the grating used in its own light-splitting unit, and the spectral width of the fitting sampling point is relatively narrow. Then cause the problem of lower resolution; and for the second device, because it uses optical filters to obtain light intensities of different wavelengths, and due to the determination of the number of collection holes on the filter and the film attached to the collection holes The determination of transmitted light makes the number and position of light intensity sampling points fixed, and the accuracy is relatively low

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