Semiconductor Alignment Key Patterns for Dense Lithography Control
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Solution Overview
Problem
The increasing integration density of semiconductor devices leads to challenges in the fabrication process, including process failures, due to the need for smaller pattern sizes and higher precision, which existing technologies struggle to address effectively.
Innovation Solution
A semiconductor device design that includes a substrate with a chip region and an edge region featuring coarse key patterns divided into fine key patterns, and a method of fabricating the device using multiple mask layers and spacer formations to enhance process monitoring and reduce fabrication errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If integration density is increased to achieve faster operating speed and lower power consumption, then operational efficiency is improved, but manufacturing precision deteriorates due to smaller pattern sizes
Solution Approach 1:
The patent divides the key pattern into multiple fine key patterns (first fine key pattern, second fine key pattern, third fine key pattern) arranged in different directions. This segmentation allows each fine key pattern to be formed with relaxed dimensional constraints while collectively providing comprehensive alignment reference, thus resolving the contradiction between high integration density and manufacturing precision.
Solution Approach 2:
The patent extends the alignment reference from a single linear key pattern to a two-dimensional array of fine key patterns arranged in multiple directions (first direction, second direction, third direction). This dimensional expansion provides redundant alignment references that compensate for the reduced size of individual patterns, maintaining manufacturing precision despite increased integration density.
2Productivity
If pattern size is reduced to increase integration density, then productivity is improved, but reliability deteriorates due to process failures
Solution Approach 1:
The patent applies different pitch specifications to fine key patterns in different directions: the first pitch (first direction) is larger than the second pitch (second direction), which is larger than the third pitch (third direction). This local differentiation optimizes each direction's fine key patterns for their specific alignment requirements, reducing process failures while maintaining high integration density.
Solution Approach 2:
The fine key patterns are formed in advance as part of the substrate structure before device fabrication begins. These pre-formed patterns serve as permanent alignment references throughout the manufacturing process, eliminating the need for repeated alignment operations and reducing cumulative process failures.
3Manufacturing precision
If multiple mask layers and spacer formations are used to enhance process monitoring, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The fine key patterns themselves serve as the alignment references for forming subsequent patterns. The spacers are formed using the fine key patterns as masks, and the fine key patterns' geometric relationships (pitches and orientations) inherently provide the alignment information needed, eliminating the need for separate external alignment markers and simplifying the overall process.
Data Source
AI summary
A semiconductor device may include a substrate including a chip region and an edge region enclosing the chip region, and at least one coarse key pattern divided into fine key patterns on the edge region, extend in a first direction and are spaced apart from each other in a second direction crossing the first direction. Each of the fine key patterns may include a first key pattern, extending in the first direction, and a second key pattern including a first portion extending along a side surface of the first key pattern, and a second portion extending along an opposite side surface of the first key pattern. A width of each of the first and second portions may be smaller than a width of the first key pattern, when measured in the second direction.