Photomask Duty Correction for Stepped 3D Pattern Precision
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Solution Overview
Problem
The manufacturing of semiconductor devices with increased integration faces challenges in reducing manufacturing time and cost, particularly in the formation of fine patterns required for 3D structures, where errors often occur due to multiple exposure and etching processes, limiting the integration of 3D memory cells.
Innovation Solution
A method for manufacturing a photomask with pre-defined areas for duty corrections and auxiliary patterns, allowing for the formation of stepped photoresist patterns, which are analyzed to insert additional patterns for improved precision, thereby reducing manufacturing time and cost by optimizing the exposure and etching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple exposure and etching processes are performed to manufacture stepped cell structures, then 3D semiconductor device integration is achieved, but manufacturing time increases and errors occur at step boundaries
Solution Approach 1:
The patent applies preliminary action by pre-defining duty correction areas and auxiliary patterns in the photomask design stage. The photomask includes first, second, and third areas with pre-configured duty corrections, allowing the stepped photoresist pattern to be formed correctly in a single exposure process, thereby eliminating the need for multiple iterative exposure and etching processes while maintaining high precision.
Solution Approach 2:
The patent segments the photomask into distinct functional areas: a first area, a second area configured to perform first duty correction, and a third area configured to perform second duty correction. This segmentation allows each area to be optimized independently for its specific function, enabling complex stepped patterns to be formed accurately without requiring multiple processing steps.
2Manufacturing precision
If multiple exposure and etching processes are performed to manufacture stepped cell structures, then 3D semiconductor device integration is achieved, but manufacturing cost increases
Solution Approach 1:
The patent reduces manufacturing cost by performing preliminary design of duty correction areas and auxiliary patterns in the photomask. This preliminary configuration enables single-step exposure to produce accurate stepped patterns, eliminating the need for expensive ultra-fine pattern formation equipment and multiple processing cycles, thereby significantly reducing overall manufacturing cost while maintaining high precision.
Solution Approach 2:
The patent uses a photomask as a reusable template that copies the desired stepped pattern design directly onto the photoresist in a single exposure. The photomask contains pre-designed auxiliary patterns and duty correction areas that replicate the complex stepped cell structure geometry, eliminating the need for expensive iterative processing and ultra-fine pattern formation equipment.
3Manufacturing precision
If auxiliary patterns are inserted based on profile analysis, then manufacturing precision is improved, but photomask complexity increases
Solution Approach 1:
The patent applies local quality by inserting auxiliary patterns only in specific locations where profile analysis indicates they are needed. The photomask includes first, second, and third areas with auxiliary patterns strategically placed to correct duty ratios and improve profile accuracy in critical regions, rather than uniformly increasing complexity across the entire photomask structure.
Solution Approach 2:
The patent uses feedback from profile analysis of the photoresist pattern to guide the insertion of auxiliary patterns in the photomask. The cross-sectional profile is analyzed to identify areas requiring duty correction, and auxiliary patterns are subsequently inserted in those specific areas, creating a feedback-driven optimization process that improves precision without unnecessary complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables the reduction of manufacturing time and cost by enhancing the precision of pattern formation, minimizing errors, and allowing for the efficient production of 3D semiconductor devices with increased integration.
Implementation Method 1
forming a pre-photoresist pattern using the pre-photomask such that the pre-photoresist pattern has a stepped shape having at least three steps
Implementation Method 2
performing an exposure process on the pre-photoresist using the pre-photomask to form a pre-photoresist pattern
Data Source
AI summary
Provided is a method for manufacturing a photomask. The method comprises providing a pre-photomask, the pre-photomask including a first area, a second area configured to perform a first duty correction, and a third area configured to perform a second duty correction; forming a pre-photoresist pattern using the pre-photomask such that the pre-photoresist pattern has a stepped shape having at least three steps in a cross-sectional view of the pre-photoresist pattern; analyzing a profile of the pre-photoresist pattern in the cross-sectional view; and inserting an auxiliary pattern into at least one of the first to third areas, based on a result of the analyzing of the profile of the pre-photoresist pattern.