DSA Transition Region Layout for Vertical Grating Alignment
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Solution Overview
Problem
Current DSA patterning techniques in semiconductor fabrication result in undesirable horizontal morphology in transition regions, leading to polymer sheets that cause reliability and defect issues in integrated circuits.
Innovation Solution
Implement layout design modifications and DSA processes to ensure uniform gratings with vertical alignment in both active and transition regions, using block copolymers like PS-b-PMMA, and insert dummy structures to convert non-uniform gratings to DSA-compatible formats, avoiding horizontal polymer sheets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If current layout design is used for transition regions in DSA patterning, then fabrication process is simple, but horizontal morphology forms causing polymer sheet defects
Solution Approach 1:
The transition region layout is segmented into multiple uniform grating sections rather than using a single continuous non-uniform grating. This segmentation prevents the formation of horizontal morphology by breaking up the continuous pattern that causes parallel BCP orientation, while maintaining manufacturability through standardized grating units.
Solution Approach 2:
Different layout designs are applied to different regions: uniform gratings are used in transition regions to prevent horizontal morphology, while other regions may use optimized patterns for their specific functions. This local differentiation ensures reliability in transition regions without compromising overall fabrication efficiency.
2Adaptability or versatility
If non-uniform gratings are used in transition regions, then layout flexibility is maintained, but vertical alignment is compromised leading to polymer sheet formation
Solution Approach 1:
Uniform gratings are pre-configured in transition regions before the DSA process to establish the correct template for vertical BCP alignment. This preliminary structural preparation ensures that the block copolymers self-assemble in the desired vertical orientation, preventing horizontal morphology while maintaining necessary layout adaptability through grating parameter optimization.
3Manufacturing precision
If uniform gratings with pitch within 10% of BCP pitch are used, then vertical alignment is achieved eliminating polymer sheets, but layout design complexity increases
Solution Approach 1:
The grating pitch parameter is precisely controlled to be within 10% of the BCP pitch to ensure vertical alignment and eliminate polymer sheet defects. This parameter optimization achieves high manufacturing precision while managing layout complexity through systematic design rules and standardized grating configurations that can be applied across different transition region scenarios.
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
Significantly reduces or eliminates polymer sheet defects, ensuring defect-free and reliable integrated circuit fabrication with aligned vertical structures.
Implementation Method 1
block copolymers, which then self-assemble on the pattern to form the small patterns
Implementation Method 2
direct self-assembly (DSA) semiconductor patterning
Implementation Method 3
The DSA solution is annealed, and one of the block copolymers is removed
Data Source
Figure 1~2
Figure 3
Figure 4A~4B
AI summary
An integrated circuit structure includes an active region containing more active semiconductor devices, wherein the active region comprises a first grating of metal and dielectric materials with only vertically aligned structures thereon. A transition region containing inactive structures is adjacent to the active region, wherein the transition region comprises a second grating of metal and dielectric materials having at least one of vertical aligned structures and vertical random structures thereon. Both the active regions and the transition regions have an absence of non-uniform gratings with horizontal parallel polymer sheets thereon.