Extreme ultraviolet lithography process and mask

Abstract

A process of an extreme ultraviolet lithography (EUVL) is disclosed. The process includes receiving an extreme ultraviolet (EUV) mask with multiple states. Different states of the EUV mask are assigned to adjacent polygons and adjacent sub-resolution polygons. The EUV mask is exposed by a nearly on-axis illumination (ONI) with partial coherence sigma less than 0.3 to produce diffracted lights and non-diffracted lights. Most of the non-diffracted lights are removed. The diffracted lights and the not removed non-diffracted lights are collected and directed to expose a target by a projection optics box.

Description

technical field [0001] The present invention generally relates to the field of semiconductors, and more particularly, to extreme ultraviolet lithography processes and masks. Background technique [0002] The semiconductor integrated circuit (IC) industry is developing rapidly. Due to technological advancements in IC materials and designs, ICs are constantly being updated, and new generations of ICs have smaller but more complex circuits than previous generation ICs. During the development of ICs, the functional density (i.e., the number of interconnected devices per chip area) has generally increased, but the geometry size (i.e., the smallest component (or line) that can be obtained by the manufacturing process) has been reduced. . The advantages of this scale-down process are increased production efficiency and reduced associated costs. However, this scaling down process also increases the processing and manufacturing complexity of the IC. To achieve these advances, we ...

AI Technical Summary

Problems solved by technology

However, ML tends to eliminate the step heights, so a larger transition region is created between phase-shifted and non-phase-shifted regions

Therefore, limiting the resolution limit that can be achieved

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