Block Copolymer Line Density Multiplication via Reactive Infiltration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current line density multiplication processes, such as sidewall spacer 'line doubling', often result in tilted sidewall spacers due to non-perpendicular mandrel stripes, leading to degraded etched substrates.
Innovation Solution
The use of block copolymers (BCPs) and sequential infiltration synthesis (SIS) to halve pitch and double line density on a substrate without requiring mandrel stripes or sidewall spacers, where BCPs form self-assembled patterns with reactive functional groups that infiltrate inorganic material during atomic layer deposition, serving as an etch mask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If sidewall spacer line doubling is used to double line density, then manufacturing precision is improved, but the etched substrate quality deteriorates due to tilted sidewall spacers
Solution Approach 1:
The patent introduces an intermediary material layer between the substrate and the mandrel stripes. This intermediary layer serves as a buffer that compensates for substrate non-planarity and ensures perpendicular mandrel formation, thereby preventing tilted sidewall spacers while maintaining line density multiplication capability
Solution Approach 2:
The patent performs preliminary planarization by depositing the intermediary material layer before forming the mandrel stripes. This preliminary action creates a flat foundation that ensures subsequent mandrel stripes are perpendicular to the substrate, preventing the tilting problem in later processing steps
2Productivity
If mandrel stripes are used in sidewall spacer process, then line density multiplication is achieved, but device complexity increases due to additional process steps
Solution Approach 1:
The patent extracts and removes the mandrel stripes after the sidewall spacer formation is complete. By taking out the temporary mandrel structures after they have served their purpose, the process simplifies the final structure while maintaining the line density multiplication benefit
Solution Approach 2:
The mandrel stripes are discarded after serving as templates for sidewall spacer formation. The process recovers the line density multiplication benefit while eliminating the complexity of retaining temporary structures in the final device
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 effectively doubles line density with precise, perpendicular inorganic lines, improving the quality of etched substrates for nanoimprint templates and semiconductor devices.
Implementation Method 1
After deposition of the BCP on the substrate and annealing, a pattern of parallel stripes of first and second BCP components is formed with a pattern of interfaces between the components that contains the functional groups
Implementation Method 2
Each of the BCP components is non-reactive with the ALD precursors, while the functional group is reactive with the ALD precursors. The ALD results in the infiltration of inorganic material, e.g., alumina, into the interfaces where the reactive functional groups are located
Implementation Method 3
The spacer material is typically an inorganic material, typically oxides like Al2O3, and is typically formed by atomic layer deposition (ALD). ALD is a well-known thin film deposition process based on the sequential use of a gas phase chemical process, in which by repeatedly exposing gas phase chemicals known as the precursors to the growth surface and activating them at elevated temperature, a precisely controlled thin film is deposited in a conformal manner
Implementation Method 4
The organic material of the BCP components and functional groups is removed, leaving a pattern of parallel lines of inorganic material
Data Source
AI summary
Block copolymers (BCPs) and synthetic infiltration synthesis (SIS) are used to double the line density on a substrate. The BCP comprises first and second interconnected BCP components with a functional group at the junction or interface of the components. After deposition of the BCP on the substrate and annealing, a pattern of parallel stripes of first and second BCP components is formed with a pattern of functional group interfaces between the components. Each of the BCP components is non-reactive with atomic layer deposition (ALD) precursors, while the functional group is reactive with the ALD precursors. The ALD results in the infiltration of inorganic material into the interfaces where the reactive functional groups are located but without affecting the BCP components. After removal of the organic material, a pattern of parallel lines of inorganic material remains with a pitch half that of the stripes of BCP components.