Block Copolymer Deprotection Patterning for Multi-Pitch IC Features
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Solution Overview
Problem
Conventional directed self-assembly (DSA) of block copolymers is limited to single pitch patterns, which cannot match the multi-pitch patterns required in integrated circuit (IC) fabrication, leading to poor resolution and high roughness in IC device patterning.
Innovation Solution
In-situ formation of block copolymers through deprotection reactions, guided by chemically amplified resists (CARs) with protected, cross-linked polymers, allows for flexible or unlimited pitch ranges and improved resolution and roughness by controlling the deprotection process with light exposure and post-exposure bake.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional directed self-assembly (DSA) of block copolymers is used, then the process is simple and straightforward, but it is limited to single pitch patterns which cannot match multi-pitch patterns required in IC fabrication
Solution Approach 1:
The patent applies preliminary action by pre-forming a guiding pattern layer with specific pitch dimensions before introducing the block copolymer. This guiding pattern is created through light exposure and deprotection reactions that establish a template structure, enabling the subsequent self-assembly process to produce multi-pitch patterns rather than being limited to single pitch. The guiding pattern layer is prepared in advance with the exact dimensional characteristics needed for the final multi-pitch structure.
Solution Approach 2:
The patent uses an intermediary approach by introducing a guiding pattern layer as a mediating structure between the conventional DSA process and the desired multi-pitch outcome. This guiding pattern acts as an intermediate template that directs the self-assembly of block copolymers to form complex multi-pitch patterns. The guiding pattern layer mediates the transformation from simple single-pitch DSA to complex multi-pitch patterning by providing a structured template that the block copolymer follows during self-assembly.
2Manufacturing precision
If conventional DSA of block copolymers is used, then the process is straightforward, but it produces poor resolution and high roughness in IC device patterning
Solution Approach 1:
The guiding pattern layer serves as an intermediary template that significantly improves pattern resolution. By providing a pre-formed structural template with precise dimensions, the guiding pattern enables the block copolymer self-assembly to achieve much higher resolution patterns. The intermediary guiding pattern acts as a molecular template that directs the formation of high-resolution features, transforming the poor resolution output of conventional DSA into high-quality multi-pitch patterns suitable for advanced IC fabrication.
Solution Approach 2:
The preliminary formation of the guiding pattern layer with controlled dimensions and structure enables subsequent high-resolution patterning. By preparing the guiding pattern in advance with precise dimensional control through light exposure and deprotection, the process establishes a high-resolution template that directs the final pattern formation. This preliminary structuring action ensures that the subsequent self-assembly produces high-resolution features rather than the poor resolution typical of conventional DSA.
3Manufacturing precision
If conventional DSA of block copolymers is used, then the process is simple, but it produces high roughness in the patterned structures
Solution Approach 1:
The guiding pattern layer acts as an intermediary that reduces pattern roughness by providing a smooth, well-defined template structure. This intermediate template guides the block copolymer self-assembly to form patterns with reduced roughness compared to conventional DSA. The guiding pattern's structured template effect smooths out the roughness that would otherwise be inherent in direct block copolymer self-assembly, producing smoother final patterns suitable for high-precision IC fabrication.
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 method enables the formation of patterns with enhanced resolution and reduced roughness, overcoming the limitations of conventional DSA by providing multi-pitch patterning capabilities in IC fabrication.
Implementation Method 1
the photoacid generator may decompose, which may generate one or more photoacids
Implementation Method 2
Phase separation during the DSA of a block copolymer can produce a DSA pattern
Implementation Method 3
directed self-assembly (DSA) of block copolymers
Implementation Method 4
heating the layer to a temperature within a range from about 80 degrees Celsius to about 200 degrees Celsius
Data Source
AI summary
In-situ formation of a block copolymer through deprotection can provide patterns with flexible pitches. A layer of a protected polymer including a protecting group is formed. One or more portions of the layer may be exposed to light. The exposed portion(s) may be baked after the light exposure. The protecting group is removed after the light exposure or bake so that the protected polymer becomes a deprotected polymer in the exposure portion(s). The deprotected polymer is bonded with the protected polymer in the unexposed portion(s) of the layer but has a different solubility from the protected polymer so that phases of the block copolymer are separated. The phase separation can provide a periodic pattern with various pitches. The solution and roughness of the pattern can be enhanced by using CARs formed with a protected, cross-linked polymer that includes a protective group and a function group with a ratio of 50:50.