A method for measuring the curvature radius of transparent wafer surface with automatic calibration and compensation

Abstract

The invention discloses a method for measuring the radius of curvature of a transparent wafer surface with automatic calibration and compensation, and relates to the field of semiconductor technology. The method includes: establishing the corresponding relationship between each wavelength and a distance value; determining the detection range of the wafer; Go to the detection position of the transparent wafer, move the transparent wafer to the center of the wafer detection range; judge whether the detection position is within the wafer detection range: if not, record the axial adjustment height value; if so, select the reflected light small hole transmittance The maximum wavelength is used as the focal wavelength of the detection position, and the corresponding distance value is obtained; the compensation is calculated to obtain the height change value; the confocal ranging sensor is moved to the next detection position, and the judgment step is re-executed until all detection positions are detected; for all heights The change value is fitted to obtain the surface curvature radius of the transparent wafer in a diameter direction. This method is suitable for the measurement of transparent wafers, and automatically calibrates and compensates the measured values ​​to obtain high-precision surface curvature radii.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for measuring the curvature radius of a transparent wafer surface with automatic calibration and compensation. Background technique [0002] In the semiconductor wafer preparation process, it is necessary to form a film on the surface of the substrate. Due to the different thermal expansion coefficients of different materials, the warping and deformation of the substrate will be caused during the coating process. Excessive stress will seriously affect the film performance and photolithography. Accuracy, and even lead to fragmentation of the wafer during the transfer process, causing equipment contamination and damage, and huge economic losses to the manufacturer. Coating stress measurement helps to adjust the coating process in time, eliminate bad films, and improve manufacturing efficiency. [0003] Traditional film stress measurement equipment first measures th...

AI Technical Summary

Problems solved by technology

However, the stress calculation needs to be collected before and after coating, and the measured material will inevitably change. Different materials have different spectral reflectances. Only one data calibration for a certain material will cause large errors when the material is replaced.

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