Overlay Accuracy Detection Graphics and Its Application Method

Abstract

The invention relates to an alignment precision detection pattern and a usage method thereof. The alignment precision detection pattern is arranged in the current layer of photolithography patterns and is a pattern which is formed by arrangement of a plurality of holes and has a frame-shaped outer contour, the alignment precision detection pattern comprises at least one first region and a second region, spatial periods of first regions are shorter than the spatial period of the second region, and dimensions of holes are equal to the characteristic dimension of the current layer of photolithography patterns. According to the alignment precision detection pattern and the usage method thereof, the characteristic dimension pattern is embedded inside the alignment precision detection pattern, so that the alignment precision detection pattern and the usage method have the advantages that the area occupied by the characteristic dimension pattern and the alignment precision detection pattern during chip production is reduced, and the problem that characteristic dimension detection is affected due to the fact that the characteristic dimension detection pattern is damaged by electron irradiation can be solved.

Description

Technical field [0001] The present invention relates to a photoetching technique, in particular to an over-etching precision detection pattern and a method of use thereof. Background technique [0002] As the integration of semiconductor chips continues to increase, the feature size of transistors continues to shrink to the nanometer level, and the production process becomes more and more complex. In production, the three-dimensional structure of various components is decomposed into dozens of layers of two-dimensional lithography patterns. In order to achieve good device performance, each photolithography pattern must not only have precise feature size line widths, but also ensure precise overlay (alignment) between layers. [0003] Overlay accuracy detection is usually to set a overlay accuracy detection pattern in the upper and lower lithography layer patterns. By maintaining the alignment of the relative positions of the two overlay accuracy detection patterns, the alignment o...

AI Technical Summary

Problems solved by technology

When the electron beam is irradiated on the photoresist, it will cause electron irradiation damage to the photoresist, resulting in deformation of the photoresist pattern and affecting the measurement results of the feature size line width

In order to reduce the electron irradiation damage to the photoresist, it is necessary to add an additional pattern to determine the position of the feature size detection pattern, which further increases the area occupied by the pattern

And the measurement time of each feature size inspection pattern is limited

When it is necessary to repeat the measurement of the feature size detection pattern, the measurement result will be affected by the electron irradiation damage of the photoresist

The disadvantages of the existing technology are: since the feature size detection pattern and the overlay accuracy detection pattern are respectively placed in different areas of the current layer photolithography pattern, the pattern occupies a large area, and the measurement time of the feature size is too long, resulting in a large measurement result. Can be affected by electron irradiation damage of photoresist

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