Spacer Patterning for Fine Pattern Precision
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Solution Overview
Problem
The semiconductor industry faces limitations in forming fine patterns due to the resolution limits of photolithography processes, necessitating advanced patterning technologies such as double patterning technology (DPT) or spacer patterning technology (SPT) to achieve nano-scale critical dimensions in high integration density semiconductor devices.
Innovation Solution
A method involving the formation of sacrificial patterns, spacers, and mask layers to create opening patterns that expose and separate portions of the underlying layer, allowing for the formation of fine patterns with precise control over sub-patterns and spacings, utilizing photolithography processes with varying resolution limits to overcome traditional limitations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithography process is used to form fine patterns, then manufacturing process is simple, but manufacturing precision deteriorates due to resolution limits
Solution Approach 1:
The patent divides the patterning process into multiple stages: first forming a sacrificial pattern, then forming spacers on its sidewalls, removing the sacrificial pattern, and finally forming opening patterns through the spacers. This segmentation allows each stage to be optimized independently, achieving nano-scale precision through cumulative refinement rather than attempting to achieve it in a single photolithography step.
Solution Approach 2:
The sacrificial pattern is formed in advance as a template structure that defines the positions where spacers will be deposited. This preliminary action establishes a framework that guides subsequent spacer formation and ensures precise spatial arrangement before the actual fine patterns are created, enabling control over pattern spacing and alignment.
2Manufacturing precision
If spacer patterning technology is used to form fine patterns, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The sacrificial pattern serves as an intermediary structure that facilitates spacer formation. It is temporarily created to provide a template for spacer deposition, then removed after serving its purpose. This intermediary approach enables precise spacer positioning without requiring complex direct patterning methods, as the sacrificial pattern simplifies the spacer formation process through self-aligned deposition.
Solution Approach 2:
The patent transitions from two-dimensional planar patterning to three-dimensional spacer formation by depositing material on the sidewalls of the sacrificial pattern. This dimensional change allows pattern definition to occur in the vertical dimension through spacer height and sidewall angle control, then transferring the pattern back to the horizontal plane, enabling precision beyond conventional photolithography limits.
3Productivity
If integration density is increased, then productivity is improved, but manufacturing precision requirements worsen
Solution Approach 1:
The spacers self-align to the sacrificial pattern through conformal deposition on their sidewalls, automatically defining their positions and spacing. This self-service mechanism eliminates the need for additional alignment steps and photolithography patterning for the fine features, enabling high integration density to be achieved through the inherent geometry of the spacer formation process rather than through increasingly precise lithography.
Data Source
AI summary
There is provided a method for forming fine patterns. The method includes forming a pattern divider on an underlying layer, forming a mask layer on the underlying layer to cover the pattern divider, forming an opening pattern that vertically penetrates the mask layer to expose a portion of the pattern divider and intersects the exposed portion of the pattern divider, and selectively removing portions of the underlying layer exposed by the opening pattern of the mask layer to form a couple of opening sub-patterns.