Phase shift mask and detection method for light transmission uniformity of slit of photoetching machine

Abstract

The embodiment of the invention discloses a phase shift mask and a detection method for light transmission uniformity of a slit of a photoetching machine. The detection method comprises the following steps: respectively exposing on a first test silicon wafer at different focal plane positions according to a preset exposure dose by using a first phase shift mask; detecting a phase shift error of each marked pattern at different focal plane positions, fitting a relation curve between the phase shift error and the focal plane position, and obtaining a slope '; calculating a longitudinal intercept b'of a slope corresponding to each marked pattern and an exposure dose fitting straight line; and finally, determining the uniformity of slit illumination according to the dispersion of the longitudinal intercept b'of each marked pattern. The embodiment of the invention can solve the problem that the existing illumination uniformity measurement can only adopt off-line measurement, not only can adapt to complex and changeable actual working conditions, but also can quickly judge whether the vertical illumination system needs to be recalibrated or not, simplify the measurement process, and ensure that a machine does not stop and continuous production is realized.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of lithography machines, and in particular, to a phase-shift mask and a method for detecting the uniformity of light transmission through slits in a lithography machine. Background technique [0002] At present, the illumination uniformity test of the lithography machine mainly adopts the offline measurement strategy, which is realized by the sensor inside the lithography machine. However, the sensor measurement adopts a fixed mode and cannot adapt to the complex and changeable actual working conditions. The final exposure result may be different from the sensor measurement. The results are different. The CDU often used in the process can also characterize the lighting uniformity to a certain extent, but the CDU itself is the result of the combined action of many factors, and it cannot accurately measure the lighting uniformity and locate the abnormal position. SUMMARY OF THE INVENTIO...

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Problems solved by technology

[0002] At present, the illumination uniformity test of the lithography machine mainly adopts the off-line measurement strategy, which is realized by the sensor inside the lithography machine. However, the sensor measurement adopts a fixed mode, which cannot adapt to complex and changeable actual working conditions. The final exposure result may be different from the sensor measurement. There is a difference in the results

The CDU that is often used in the process can also characterize the uniformity of illumination to a certain extent, but the CDU itself is the result of a combination of factors, and cannot accurately measure the uniformity of illumination and locate abnormal locations

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