A method and device for measuring film thickness

Abstract

The invention discloses a method for measuring the thickness of a membrane. The method comprises the steps that firstly, the dividing line of the membrane is determined according to different reactive forces borne by a probe; secondly, the thickness of the membrane is worked out according to position data measured by a displacement sensor on the probe or the time and movement speed for the probe to penetrate through the membrane. According to the method, the dividing line of the membrane is determined according to the change of the reactive forces that the rigid probe penetrates through the membrane, the time when the probe starts to penetrate through the membrane and the time when the probe right penetrates through the membrane are determined according to the time when the reactive forces suddenly change, then the thickness of the membrane is worked out according to the probe movement speed and the penetrating time, the thickness of the membrane can be worked out according to the position data of the probe, samples do not need to be moved in the measuring process, only the probe needs to be moved, the measuring method is simple and easy to operate, the error of the obtained thickness data of the membrane is small, the obtained thickness is closer to the actual thickness, and accuracy is high. The invention further provides a device for achieving the method for measuring the thickness of the membrane.

Description

technical field [0001] The invention relates to the field of display technology, in particular to a method and device for measuring film thickness. Background technique [0002] At present, the commonly used methods for measuring the thickness of solid thin films mainly include probe method and optical method. The measurement principle of the probe method is to use a mechanically sensitive probe to slide along the surface of the sample, record the surface topography, and measure the film thickness; the optical method uses light interference or diffraction to measure the film thickness. [0003] In the process of measuring with the optical method, it is necessary to pre-fabricate the cross section of the sample, obtain the cross-sectional image, and then calculate the thickness of each film layer according to the image, but the surface of the film layer may be warped and the boundaries may be blurred during the process of sample preparation. Phenomenon, resulting in inaccura...

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Problems solved by technology

[0003] In the process of measuring with the optical method, it is necessary to pre-fabricate the cross section of the sample, obtain the cross-sectional image, and then calculate the thickness of each film layer according to the image, but the surface of the film layer may be warped and the boundaries may be blurred during the process of sample preparation. Phenomenon, resulting in inaccurate final thickness data

If the surface of the sample is uneven, in order to be able to measure the level difference between the film area and the non-film area, it needs to be leveled manually during the measurement process, and then the thickness of the film layer can be calculated by software, but due to the test range, machine flatness and artificial leveling Due to the influence of operating errors in the process, the error between the obtained film thickness data and the actual thickness is relatively large

Using the optical method to measure not only the cross-section will affect the measured thickness data, but also the scope of application is relatively narrow. For the surface of the sample coated with various layers, it is inconvenient to use the optical method to measure the thickness of the film layer, even if the optical method can be used. The accuracy of the data will also be greatly affected

[0004] To sum up, the use of optical methods to measure film thickness not only requires the preparation of samples, but also increases the cost of measurement, and the measured film thickness has a larger error than the actual thickness, resulting in very low accuracy.

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