Directed Self-Assembly Pattern Formation for CD Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional double patterning technologies face challenges in achieving uniform critical dimension (CD) uniformity and smaller feature sizes, particularly in sub-40 nm half-pitch scales, due to the inherent shape differences in hole patterns formed by existing methods.
Innovation Solution
The method employs directed self-assembly materials, specifically block copolymers, to fill concave portions on a substrate, allowing for the diffusion of these materials to form uniformly sized holes with improved CD uniformity by using a core layer, spacer layer, and etch back processes, enabling the formation of patterns with smaller feature sizes and uniform shapes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional double patterning technology is used to form hole patterns, then the pitch size can be reduced below photolithography resolution limits, but the hole patterns exhibit two different shapes resulting in poor CD uniformity
Solution Approach 1:
The directed self-assembly material automatically organizes itself into uniform circular hole patterns through spontaneous self-assembly mechanisms, eliminating the need for external patterning steps and ensuring consistent shape and size across all holes without manual intervention
Solution Approach 2:
The patent changes the physical and chemical parameters of the patterning process by introducing directed self-assembly materials that respond to specific environmental conditions (temperature, solvent, concentration) to spontaneously form uniform patterns, transforming the process from mechanically imposed patterns to thermodynamically driven self-organization
2Manufacturing precision
If photolithographic process is used to form resist patterns, then the process is simple and well-established, but the maximum resolution is preset and cannot form patterns finer than the apparatus resolution limit
Solution Approach 1:
The patent segments the patterning process into distinct stages: forming core layer patterns with conventional photolithography, depositing spacer layers, and introducing directed self-assembly materials that further subdivide and refine the patterns, achieving resolution beyond single-step photolithography limits
Solution Approach 2:
The patent adds a new dimension to the patterning process by introducing a self-assembly dimension that operates independently from photolithography resolution constraints, using vertical spacer deposition and horizontal self-assembly diffusion to create patterns at scales unreachable by conventional optical methods
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 contact or via hole patterns with enhanced CD uniformity and smaller feature sizes, overcoming the limitations of conventional double patterning techniques by ensuring consistent shape and size across the pattern array.
Implementation Method 1
the directed self-assembly material filling up the first concave portions and the second concave portions diffuse to the boundaries of the first concave portions and the second concave portions
Implementation Method 2
activating a directed self-assembly process so that the directed self-assembly material filling up the first concave portions and the second concave portions diffuse to the boundaries
Data Source
AI summary
A method for forming a pattern includes steps of forming a patterned core layer on a substrate, conformally forming a spacer layer on the patterned core layer to form first concave portions, performing an etch back process to expose the patterned core layer, removing the exposed patterned core layer to form second concave portions, filling up the first concave portions and the second concave portions with a directed self-assembly material, and activating a directed self-assembly process, so that the directed self-assembly material is diffused to the perimeter of the concave portions to form a hole surrounding by the directed self-assembly material in each concave portions.