DSA Patterning via Single Lithography and Etching
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Solution Overview
Problem
Current semiconductor fabrication techniques require multiple patterning processes to achieve smaller critical dimensions, leading to challenges in pattern placement and overlay due to insufficient lithography resolution.
Innovation Solution
A patterning method utilizing directed self-assembly (DSA) patterns formed from a block polymer material layer, where a single lithography process creates a patterned photoresist layer that exposes or shields DSA patterns, allowing for etching to form fine patterns without the need for multiple exposures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional photolithography method is used, then the process is simple, but the resolution is insufficient to fabricate smaller critical dimensions
Solution Approach 1:
The patent segments the patterning process into two distinct stages: first forming DSA patterns with sub-lithographic dimensions, then using a single lithography exposure to create the final pattern. This segmentation allows each stage to optimize for its specific function, achieving high resolution without requiring multiple lithography exposures.
Solution Approach 2:
The patent performs preliminary action by pre-forming the DSA patterns before the lithography step. These pre-formed patterns serve as a template that guides the subsequent lithography process, enabling the final pattern to achieve resolution beyond what the lithography tool could achieve alone.
2Manufacturing precision
If multiple patterning methods are used to achieve smaller critical dimensions, then the resolution improves, but the pattern placement and overlay challenges increase
Solution Approach 1:
The patent employs self-service through directed self-assembly, where the block copolymer automatically forms ordered patterns with precise spacing and alignment without requiring external guidance. This self-organized structure ensures consistent pattern placement and eliminates overlay errors that typically arise from multiple lithography alignments.
3Manufacturing precision
If multiple lithography exposures are used for patterning, then smaller critical dimensions can be achieved, but the process time and complexity increase
Solution Approach 1:
The patent merges the pattern formation function into a single lithography step that works in conjunction with the pre-formed DSA patterns. Instead of using multiple separate lithography exposures, the process combines the self-assembled pattern template with one lithography exposure to achieve the final pattern, significantly reducing process time.
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
Enables the formation of fine patterns with resolutions below traditional photolithography limits using a single lithography process, reducing the complexity and cost associated with multiple patterning methods.
Implementation Method 1
annealing is performed on the DSA material layer and one of the block components is removed to form mutually separate and isolated DSA patterns
Implementation Method 2
a plurality of directed self-assembly (DSA) patterns are formed on the material layer
Implementation Method 3
a patterned photoresist layer is formed by using a single lithography process
Data Source
AI summary
A patterning method is provided. First, a material layer is formed over a substrate. Thereafter, a plurality of directed self-assembly (DSA) patterns are formed on the material layer. Afterwards, a patterned photoresist layer is formed by using a single lithography process. The patterned photoresist layer covers a first portion of the DSA patterns and exposes a second portion of the DSA patterns. Further, the material layer is patterned by an etching process, using the patterned photoresist layer and the second portion of the DSA patterns as a mask.