A method for measuring optical constant and thickness of metal absorbing film layer

Abstract

The invention discloses a method for measuring the optical constant and the thickness of metallic absorbing film layers, relates to the field of coated glass, and solves the problem that the optical constant and the thickness of the metallic absorbing film layer cannot be accurately and timely measured in the prior art. According to the technical scheme, the method includes: producing N film-coated samples, wherein each film-coated sample comprises a substrate and one metallic absorbing film layer coating the substrate; measuring the transmittance spectrum, in a preset wavelength range, of each film-coated sample; initially setting the parameters of an optical constant polynomial model and the film layer thickness of each film-coated sample to form initial values; using a genetic algorithm, using the initial values as searching starting points and using the transmittance spectrums as searching basis to obtain the refractive index, extinction coefficient and thickness of the metallic absorbing film layers. The method is mainly used for timely and accurately measuring the optical constant and the thickness of the metallic absorbing film layers so as to simplify a product design, development and production control process and reduce enterprise equipment investment cost.

Description

technical field [0001] The invention relates to the field of coated glass, in particular to a method for measuring the optical constant and thickness of a metal absorption film layer. Background technique [0002] Coated glass (such as offline LOW-E coated glass, solar control coated glass, etc.) is coated with one or more layers of thin film on the surface of the glass to change the optical properties of the glass to meet certain specific requirements. The metal absorbing film layer plays the role of sunshade, improving film adhesion and environmental resistance in the film system. For example, the metal absorbing film layer is used as a sacrificial layer in the off-line low-emissivity (LOW-E) film system, which can prevent the low-emissivity functional layer (such as noble metal Ag film) from being oxidized or corroded in subsequent processing and storage, and can improve low-emission The adhesion of the radiation functional layer (eg, Ag thin film); in the solar control ...

AI Technical Summary

Problems solved by technology

When using a step meter to measure the thickness of the film layer, steps need to be prepared, the sample preparation cycle is long, and the thickness of the metal absorbing film layer is generally less than 20nm. Because the surface of the metal film layer is relatively soft, when using the step method to measure the thickness, due to the physical contact of the probe It will cause scratches on the film layer, and the measurement error will be large under the condition that the height of the step is less than 20nm

[0004] In view of the above-mentioned deficiencies in the existing professional testing instruments, these testing instruments cannot obtain the actual optical constants and thickness of the film in a timely and accurate manner, making it difficult for the factory to obtain the actual optical constants of the metal absorbing film in a timely and accurate manner. and thickness, resulting in a disconnection between the input parameters and the actual when using the film system design software

Images