Directed Self-Assembly Films With High-Boiling Solvent for Small-Pitch Wafers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional photolithography techniques, especially those using extreme ultraviolet (EUV) light, face challenges in forming small pitch features due to stochastic effects that result in uneven edges and surfaces, leading to poorly functioning integrated circuit features.
Innovation Solution
The use of directed self-assembly processes with block copolymers and high boiling point solvents enables rapid and efficient formation of small pitch features by self-assembling into well-ordered morphologies at higher temperatures for shorter durations, overcoming the limitations of traditional photolithography.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If EUV light is used to pattern photoresist for small pitch features, then smaller feature sizes can be achieved, but stochastic effects cause uneven edges and surfaces leading to poor circuit functionality
Solution Approach 1:
The patent introduces an intermediary self-assembled polymer layer between the photoresist and the substrate. This intermediary layer, formed through directed self-assembly of block copolymers, serves as a template that guides the formation of small pitch features with uniform dimensions. The intermediary structure compensates for the stochastic effects of EUV lithography by providing a physically self-organized pattern that ensures edge uniformity and surface flatness, thereby maintaining circuit functionality while enabling smaller feature sizes.
Solution Approach 2:
The patent segments the feature formation process into two distinct stages: first, photolithography creates a relaxed pattern with larger pitch; second, directed self-assembly of block copolymers creates the final fine-pitch pattern. This segmentation allows each process to operate at its optimal scale - photolithography for initial pattern definition and self-assembly for precision feature formation - thereby achieving small pitch features with high reliability without the stochastic defects of direct EUV patterning.
2Ease of manufacture
If traditional photolithography is used, then the process is simple and well-established, but the minimum feature size is limited by the wavelength of light
Solution Approach 1:
The patent segments the feature formation process into two distinct stages: first, photolithography creates a relaxed pattern with larger pitch; second, directed self-assembly of block copolymers creates the final fine-pitch pattern. This segmentation allows each process to operate at its optimal scale - photolithography for initial pattern definition and self-assembly for precision feature formation - thereby achieving small pitch features with high reliability without the stochastic defects of direct EUV patterning.
Solution Approach 2:
The patent introduces an intermediary self-assembled polymer layer between the photoresist and the substrate. This intermediary layer, formed through directed self-assembly of block copolymers, serves as a template that guides the formation of small pitch features with uniform dimensions. The intermediary structure compensates for the stochastic effects of EUV lithography by providing a physically self-organized pattern that ensures edge uniformity and surface flatness, thereby maintaining circuit functionality while enabling smaller feature sizes.
3Manufacturing precision
If directed self-assembly with high boiling point solvent is used, then small pitch features form faster with better precision, but the process complexity increases
Solution Approach 1:
The patent employs directed self-assembly where block copolymers autonomously organize into ordered micellar structures with dimensions determined by their molecular architecture. The high boiling point solvent facilitates this self-organization by maintaining polymer mobility at elevated temperatures without rapid evaporation, allowing the system to self-correct and form uniform features. This self-service mechanism reduces the need for complex external control systems, as the material itself drives the precision feature formation through thermodynamic self-organization.
Solution Approach 2:
The patent utilizes parameter changes in the solvent system - specifically employing high boiling point solvents that remain liquid at elevated annealing temperatures. This parameter change enables thermal processing at higher temperatures that accelerate self-assembly kinetics and improve feature uniformity, while the high boiling point prevents solvent loss that would disrupt the self-organization process. The controlled change in thermal parameters drives the system toward equilibrium structures with superior precision.
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 results in faster and more reliable formation of small pitch features, enhancing the performance and yield of semiconductor wafers and integrated circuits while avoiding the distortions associated with EUV photolithography.
Implementation Method 1
forming, from the self-assembly material, first polymer structures of a first polymer material and second polymer structures of a second polymer material in a pattern based on the patterned structure
Implementation Method 2
performing a rapid thermal annealing process to cause the block copolymer material to self-assemble
Data Source
AI summary
A system and method utilize directed self-assembly films, including block copolymers and solvents, to form features on a wafer. The solvents have high boiling points. The high boiling points of the solvents enable directed self-assembly processes to utilize very high temperature, rapid thermal annealing processes to generate a pattern of first and second polymer structures over a wafer from the directed self-assembly films. The pattern of the first and second polymer structures can be utilized to form the features on the wafer.