DSA Patterning Over Non-Uniform Metal Layers With Assisting Features
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Solution Overview
Problem
The challenge in integrated circuit manufacturing is the difficulty in forming consistent patterned layers over conductive layers with non-uniform features, such as insulator regions within metal gratings or gate layers with varying gate lengths, using directed self-assembly (DSA) processes.
Innovation Solution
The implementation of DSA assisting features in irregular or non-uniform regions of conductive layers helps to form consistent patterns by creating a guiding pattern that improves the assembly of polymer structures, thereby enhancing control over via placement and reducing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If DSA processes are used to form patterned layers over conductive layers with non-uniform features, then manufacturing complexity is reduced, but pattern uniformity deteriorates
Solution Approach 1:
The patent applies local quality by introducing DSA assisting features specifically in non-uniform regions (such as insulator regions within metal gratings or areas with varying gate lengths) rather than uniformly across the entire conductive layer. These assisting features have different properties than the surrounding uniform regions, providing localized guidance to polymer structures only where needed to maintain pattern uniformity while keeping the rest of the process simple.
Solution Approach 2:
The DSA assisting features act as an intermediary element between the non-uniform conductive layer and the polymer structures. They mediate the self-assembly process by providing a guiding pattern that helps polymer structures navigate around irregularities in the underlying conductive layer, thereby maintaining overall pattern uniformity without requiring complex manufacturing processes.
2Manufacturing precision
If DSA assisting features are added to guide polymer assembly, then pattern precision is improved, but device complexity increases
Solution Approach 1:
The patent segments the conductive layer into uniform regions and non-uniform regions, applying DSA assisting features only in the non-uniform regions. This segmentation approach allows the majority of the device to remain simple while adding complexity only where necessary to achieve precise patterns in problematic areas.
Solution Approach 2:
By confining DSA assisting features to specific non-uniform regions rather than applying them universally, the patent maintains local quality where needed while minimizing overall device complexity. The assisting features are strategically placed only in areas where they provide value for pattern precision.
3Device complexity
If DSA is performed over non-uniform conductive layers, then manufacturing process is simplified, but overlay tolerance deteriorates
Solution Approach 1:
The DSA assisting features serve as an intermediary guiding layer that mediates between the non-uniform conductive layer and the subsequent polymer pattern formation. This guiding pattern ensures that polymer structures align correctly even over irregular underlying features, maintaining overlay tolerance without complicating the overall manufacturing process.
Solution Approach 2:
The patent applies preliminary action by forming DSA assisting features and guiding patterns before the polymer self-assembly process. This pre-prepared guidance structure is in place to direct polymer formation, ensuring correct overlay and alignment before the actual pattern formation occurs, thereby maintaining precision while keeping the process simple.
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
This approach enables the generation of patterned layers with high uniformity and precision at tight pitches, improving overlay tolerances and critical dimension control, which is essential for advanced microelectronic devices.
Implementation Method 1
the diblock copolymer self-assembles based on the guiding pattern, with, e.g., polymer A forming over insulator portions of the metal grating, and polymer B forming over metal portions of the metal grating
Data Source
AI summary
Described herein are IC devices include patterned conductive layers, such as metal gratings and gate layers, and patterned layers formed over the patterned conductive layers using a directed self-assembly (DSA)-enabled process with DSA assisting features. A patterned conductive layer may have non-uniform features, such as large regions of insulator within a metal grating, or varying gate lengths across a gate layer. The DSA assisting features enable the formation of patterned layers, e.g., layers with different hard mask materials replicating the structure of the conductive layer below, even over non-uniform features.