Sub-Region Mask Optimization for Semiconductor Pattern Transfer
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Solution Overview
Problem
Current semiconductor fabrication techniques face challenges in achieving precise pattern transfer due to dimension errors caused by optical proximity effects and varying pattern densities, leading to difficulties in maintaining high precision across all patterns on semiconductor substrates.
Innovation Solution
The method involves dividing the pattern region into sub-regions, calculating and applying specific illumination light shapes and mask pattern corrections for each sub-region to minimize dimension errors, and using a pattern writing apparatus to sequentially transfer these corrected patterns onto the semiconductor substrate through multiple exposures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single illumination shape and mask pattern are used for the entire pattern region, then the fabrication process is simple, but dimension errors occur due to optical proximity effects and varying pattern densities
Solution Approach 1:
The pattern region is divided into multiple sub-regions, each with its own optimized illumination shape and mask pattern. This segmentation allows dimension errors to be minimized in each local area while accounting for optical proximity effects and pattern density variations specific to that sub-region.
Solution Approach 2:
Different illumination shapes and mask patterns are applied to different sub-regions based on their specific characteristics. This local optimization ensures that each area receives the most appropriate configuration for its pattern density and geometric features, improving overall manufacturing precision.
2Measurement precision
If illumination shape is selected by fitting to the pattern to be transferred, then resolution is improved, but the actual mask pattern differs causing dimension errors
Solution Approach 1:
The illumination shape and mask pattern are pre-calculated and optimized for each sub-region before the actual pattern transfer. This preliminary optimization accounts for optical proximity effects and ensures that the mask pattern, when transferred with the calculated illumination shape, achieves the desired dimension accuracy.
Solution Approach 2:
The system uses calculated combination conditions that incorporate feedback about optical proximity effects and pattern density to determine the optimal illumination shape and mask pattern for each sub-region. This feedback mechanism ensures dimension accuracy is maintained.
3Manufacturing precision
If multiple exposures are used to transfer divided sub-regions with optimized conditions, then dimension errors are reduced, but the fabrication process time increases
Solution Approach 1:
The pattern region is divided into multiple sub-regions that can be transferred through multiple exposures. This segmentation enables dimension error reduction in each exposure while allowing for optimized processing of each sub-region.
Solution Approach 2:
The illumination shape and mask pattern parameters are changed and optimized for each sub-region exposure. By calculating the appropriate combination conditions for each sub-region, the system achieves dimension precision while managing the multiple exposure process efficiently.
Data Source
AI summary
A method for fabricating a semiconductor device, includes dividing a pattern region of a desired pattern that is to be formed on a semiconductor substrate into a plurality of sub-regions; calculating combination condition including a shape of illumination light for transferring and a mask pattern obtained by correcting a partial pattern in the sub-region of the desired pattern formed on a mask used during transferring for each of the plurality of sub-regions, to make a dimension error of the partial pattern of each of the plurality of sub-regions smaller when transferred to the semiconductor substrate; and forming the desired pattern by making multiple exposures on the semiconductor substrate in such a way that the partial patterns of the sub-regions divided are sequentially transferred by transferring a pattern to the semiconductor substrate using the combination conditions calculated for each of the sub-regions.