Block Copolymer Directed Self-Assembly for Multi-Size Patterning
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Solution Overview
Problem
The existing methods for forming patterns using block copolymers in directed self-assembly processes are limited in creating multiple feature sizes in a single semiconductor device layer, as the feature size is determined by the material properties of the block copolymer, necessitating separate lithography processes for each size, increasing manufacturing complexity and cost.
Innovation Solution
A pattern forming method that involves forming multiple concave portions with different widths in a resist layer, followed by the deposition of a block copolymer film that phase-separates to create distinct patterns, allowing for the use of these patterns as masks to transfer desired features to underlying layers, thereby enabling the formation of patterns with different sizes using a single lithography process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If block copolymer directed self-assembly is used to form patterns, then fine pattern features smaller than the resist layer features can be achieved, but the feature size is determined by material properties rather than being arbitrary
Solution Approach 1:
The patent applies local quality by creating different concave portion widths (first concave portions with width W1, second concave portions with width W2) in the resist layer. This allows different regions to have different local geometries that guide the block copolymer self-assembly into corresponding different feature sizes, enabling spatial variation in pattern dimensions while maintaining the benefits of DSA
Solution Approach 2:
The patent performs preliminary action by pre-forming the resist layer pattern with multiple concave portions of different widths before introducing the block copolymer. This preliminary structuring of the substrate guides the subsequent self-assembly process to produce the desired multiple feature sizes without requiring additional lithography steps
2Adaptability or versatility
If multiple patterns with different feature sizes are formed using separate lithography processes, then arbitrary feature sizes can be achieved, but the number of manufacturing processes increases
Solution Approach 1:
The patent merges multiple patterning functions into a single lithography process by designing the resist layer to contain multiple concave portions with different widths. This single lithography step creates a multi-functional mask that guides block copolymer self-assembly into multiple different feature sizes simultaneously, eliminating the need for separate lithography processes for each pattern size
Solution Approach 2:
The resist layer pattern serves multiple functions simultaneously: it acts as a mask for fine patterning, a template for guiding block copolymer self-assembly, and a source of multiple different feature sizes. This multi-functionality allows a single process step to achieve what would traditionally require multiple specialized lithography processes
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 allows for the efficient formation of multiple patterns with different feature sizes in a semiconductor device layer using a single lithography process, reducing manufacturing complexity and cost by leveraging the phase-separation properties of the block copolymer to create precise and varied patterns.
Implementation Method 1
forming a pattern in the BCP film by phase-separating the BCP film
Implementation Method 2
a method of forming a fine pattern using directed self-assembly (DSA) of the BCP
Data Source
AI summary
A pattern forming method includes forming a first film on a first layer and a second film on the first film. First and second concave portions are formed in the second film. A third film is formed in the concave portions and a fourth film comprising a polymer is formed on the third film. The fourth film can be processed to phase separate and form a pattern in at least the first opening. The pattern formed in the fourth film can be used in patterning films thereunder. A fifth film can be formed which covers the first concave portion and does not cover the second concave portion. The third film in the second concave portion and the first film under the second concave portion can be processed using the fifth film. The first layer can be patterned using the first, second, or third film as a mask.