Lens heat effect measuring system and measuring method

Abstract

The invention discloses a lens heat effect measuring system which comprises a mask, an object marker, a lens to be measured, and a workpiece table sequentially along the direction of light transmission, and further comprises at least one machine vision system. The at least one machine vision system is located on the workpiece table. Light emitted from the object marker is imaged on the at least one machine vision system through the lens to be measured. The invention further discloses a lens heat effect measuring method.

Description

technical field [0001] The invention relates to the field of lithography, in particular to a lens thermal effect measurement system and a measurement method using a machine vision system in the field of lithography. Background technique [0002] During the exposure process, the thermal effect of the lens is a very important factor leading to the deterioration of image quality. The thermal effect of the lens refers to: due to the heat absorption of the lens during the exposure process, a small deformation occurs, which makes some optical parameters of the lens (such as magnification, distortion, defocus, wave aberration, etc.) deviate from its design value. When the exposure dose requirement becomes larger and the lens continues to absorb heat during the continuous exposure of the silicon wafer, this deformation will be more obvious. Therefore, the thermal effect of the lens must be corrected. [0003] There are currently two ways to measure the thermal effect of the lens: o...

AI Technical Summary

Problems solved by technology

[0006] 1. When the silicon wafer is heated, it is easy to deform, resulting in inaccurate sampling data;

[0007] 2. Continuous exposure to the field points will make the lines of the graph thinner, and the lines will break in some places, and even the lines will not be visible;

[0008] 3. The stray light of the lighting system is very strong, which will also cause image pollution on the silicon wafer

[0011] 1. The measurement accuracy of the sensor must be high enough, which also causes the sensor to be too expensive;

[0012] 2. There is a one-to-one correspondence between the measurement mark and the sensor, so when measuring the thermal effect, the type of mark that can be used is single;

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