Chemical Guide Layer Directed Self-Assembly Patterning
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Solution Overview
Problem
Current lithography techniques, including optical lithography and directed self-assembly (DSA), face challenges in patterning structures with dimensions and pitches below 60 nm, particularly in creating patterns with varying pitches and dimensions required for semiconductor device applications, and are limited by the width constraints of DSA materials.
Innovation Solution
A method involving the formation of a chemical guide layer and a template with alternating etchable and etch-resistant components, where the etchable components are removed to pattern the process layer using the etch-resistant components as a mask, allowing for the creation of both periodic and non-periodic patterns with increased width and reduced pitch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If optical lithography is used for patterning, then high-throughput processing is achieved, but the patterning pitch is limited to about 80 nm
Solution Approach 1:
The patent segments the patterning process into multiple steps: first forming guide patterns via optical lithography, then using directed self-assembly to create additional patterns between the guide features. This segmentation allows the final pitch to be reduced by a factor of 2-40 relative to the guide pattern pitch while maintaining high-throughput processing for the guide pattern formation.
Solution Approach 2:
The patent introduces a chemical guide layer as an intermediary between the optical lithography guide pattern and the final self-assembled pattern. This chemical guide layer mediates the self-assembly process, enabling the formation of precise sub-60 nm patterns while the optical lithography step continues to operate at its native pitch.
2Manufacturing precision
If directed self-assembly is used to reduce pitch, then pitch reduction by a factor of 2-40 is achieved, but it is difficult to pattern lines of varying pitch and dimensions
Solution Approach 1:
The patent applies local quality by creating chemical guide layers with spatially varying properties. The chemical guide layer can have different compositions, thicknesses, or functional groups in different regions, allowing the directed self-assembly process to produce patterns with varying pitches and dimensions in different areas of the substrate while maintaining overall process control.
Solution Approach 2:
The patent introduces dynamics by making the chemical guide layer properties可调 (tunable). The chemical composition and physical characteristics of the guide layer can be dynamically adjusted during fabrication to match different patterning requirements, enabling the same DSA process to produce both constant pitch and varying pitch patterns as needed.
3Area of stationary object
If DSA material is used for patterning, then large areas of straight line/space patterns with constant pitch are formed, but the width of the pattern is limited by the characteristics of the DSA material
Solution Approach 1:
The patent applies parameter changes by systematically varying the molecular weight, composition, and architecture of the DSA materials used. By changing these parameters, the patent overcomes the inherent width limitations of standard DSA materials and achieves pattern widths of 60 nm and below, while still maintaining the ability to form large area patterns.
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 formation of precise patterns with reduced pitch and increased width, overcoming the limitations of existing technologies by effectively patterning semiconductor devices with smaller dimensions and varying pitches, while maintaining material order and avoiding defects.
Implementation Method 1
The polymeric self-assembly material contains two (or more) chemical components that have carefully controlled size. These components can be bonded together into polymer chains known as diblocks... Immediately after coating, the A and B components are relatively disordered, however, these components (A, B) can be induced to separate into distinct phases
Implementation Method 2
Directed Self-Assembly (DSA) lithography is a materials-based approach that relies on the phase separation of certain polymeric materials... By coating this polymer on a substrate with a pre-formed guide pattern, it is possible to 'interpolate' the features between the elements of the guide pattern and reduce the pitch
Data Source
AI summary
A method includes forming a chemical guide layer above a process layer. A template having a plurality of elements is formed above the process layer. The chemical guide layer is disposed on at least portions of the process layer disposed between adjacent elements of the template. A directed self-assembly layer is formed over the chemical guide layer. The directed self-assembly layer has alternating etchable components and etch-resistant components. The etchable components of the directed self-assembly layer are removed. The process layer is patterned using the template and the etch-resistant components of the directed self-assembly layer as an etch mask.