Semiconductor Pattern Formation Using Spacer-Assisted Hard Mask Patterning
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Solution Overview
Problem
Current methods for forming patterns in semiconductor devices require multiple applications of the photolithography process, making it challenging to achieve fine patterns with narrow pitches effectively.
Innovation Solution
A method involving the formation of spacers and auxiliary patterns on a hard mask to expose specific gaps, allowing for the patterning of the hard mask using these structures as a mask, thereby reducing the need for multiple photolithography steps and enabling the creation of fine patterns at a fine pitch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple photolithography applications are used to form fine patterns, then pattern precision can be improved, but manufacturing complexity and process time increase
Solution Approach 1:
The patent segments the patterning process into distinct stages: forming mandrel patterns, depositing spacer materials, selectively removing portions, and iteratively creating subsequent patterns. This segmentation allows each step to be optimized independently while achieving cumulative precision that would be difficult with repeated photolithography alone.
Solution Approach 2:
The patent performs preliminary actions by first forming mandrel patterns and spacer structures before the actual fine pattern definition. These preliminary structures serve as templates that guide subsequent patterning steps, enabling precise feature placement without requiring multiple high-precision photolithography exposures.
2Manufacturing precision
If multiple photolithography applications are used to form fine patterns, then pattern precision can be improved, but manufacturing time increases
Solution Approach 1:
The patent merges multiple patterning operations into a unified process flow where mandrel formation, spacer deposition, and pattern definition are combined into an integrated sequence. This merging reduces the total number of separate photolithography applications needed, thereby improving manufacturing efficiency while maintaining fine pattern precision.
Solution Approach 2:
By performing preliminary pattern formation and spacer creation before final pattern definition, the patent reduces the number of critical photolithography steps required. These preliminary structures are formed using simpler, faster processes that do not compromise the precision of the final pattern.
3Length of moving object
If fine patterns with narrow pitches are formed using conventional methods, then feature size can be reduced, but process reliability decreases
Solution Approach 1:
The patent employs self-aligned spacer formation where the spacer structures automatically position themselves relative to the mandrel patterns without requiring additional alignment steps. This self-service mechanism eliminates alignment errors that would compromise reliability in conventional multi-step photolithography processes, enabling consistent sub-10nm feature formation.
Solution Approach 2:
The patent changes the physical and chemical parameters of the spacer materials and deposition conditions to achieve precise control over spacer thickness and composition. By optimizing these parameters, the process achieves reliable formation of ultra-fine features that would be difficult to obtain through photolithography alone.
Data Source
AI summary
A method of forming patterns of a semiconductor device includes forming a material film on a substrate, forming a hard mask on the material film, forming a first mold mask pattern and a second mold mask pattern on the hard mask, forming a pair of first spacers to cover opposite sidewalls of the first mold mask pattern, and a pair of second spacers to cover opposite sidewalls of the second mold mask pattern, forming a first gap and a second gap to expose the hard mask by removing the first mold mask pattern and the second mold mask pattern, the first gap being formed between the pair of first spacers and the second gap being formed between the pair of second spacers, forming a mask pattern on the hard mask to cover the first gap and expose the second gap, forming an auxiliary pattern to cover the second gap, removing the mask pattern; and forming a hard mask pattern by patterning the hard mask using the first spacers, the second spacers and the auxiliary pattern as a mask.