Shrink Agent Process for Resist Pattern Dimensional Control
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Solution Overview
Problem
Current methods for shrinking resist patterns, such as RELACS and DSA, face issues with non-uniform size reduction and pattern deformation, particularly in trench patterns, leading to dimensional variations and edge roughness problems.
Innovation Solution
A pattern forming process using a resist composition with a polymer containing acid labile groups and an acid generator, followed by exposure, development, and application of a shrink agent comprising a polymer with recurring units capable of forming lactam rings in ester or ketone solvents, allowing precise size control and pattern shrinkage without deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If RELACS method is used to shrink hole pattern by crosslinking, then the resist pattern is thickened, but the size of holes becomes non-uniform due to non-uniform acid diffusion
Solution Approach 1:
The patent introduces a water-soluble amino-containing polymer as an intermediary substance that mediates between the acid catalyst and the crosslinking reaction. This polymer selectively binds to the resist surface through neutralization reaction with carboxyl groups, creating a controlled interface that prevents non-uniform acid diffusion while enabling uniform crosslinking. The polymer acts as a buffer that regulates acid distribution, thereby achieving uniform hole size despite the presence of acid catalysts.
Solution Approach 2:
The patent changes the chemical parameters of the shrinkage system by using water-soluble amino-containing polymers with specific molecular weights and functional group densities. By controlling the concentration and molecular characteristics of the polymer, the patent optimizes the neutralization reaction rate and crosslinking kinetics, thereby achieving uniform dimensional changes throughout the resist pattern while maintaining process controllability.
2Manufacturing precision
If water-soluble amino polymer is used for shrinkage via neutralization reaction, then the resist pattern is thickened, but dimensional variations after shrinkage are identical to those of the developed resist pattern
Solution Approach 1:
The water-soluble amino-containing polymer serves as an intermediary that creates a new interface layer between the resist pattern and the environment. This intermediary layer has different surface properties than the original resist, allowing it to fill in and smooth out surface irregularities. The polymer's ability to form a continuous film over the resist pattern enables it to mask underlying dimensional variations, achieving better dimensional uniformity after shrinkage than the original resist pattern possessed.
3Manufacturing precision
If DSA of block copolymer is used to shrink hole pattern, then the amount of shrinkage is increased and dimensional variation is minimized, but shape deformation occurs in trench patterns and multiple hole patterns are formed
Solution Approach 1:
The patent changes the fundamental mechanism of shrinkage from self-assembly driven (DSA) to chemically controlled crosslinking. By using water-soluble amino-containing polymers that undergo neutralization and crosslinking reactions, the patent achieves dimensional control through chemical kinetics rather than physical self-assembly. This parameter change from physical to chemical control allows the process to accommodate various pattern geometries including trenches, preventing the shape deformation and multi-hole formation issues inherent in DSA 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
The process effectively shrinks resist pattern sizes with reduced dimensional variations and edge roughness, enabling precise control and maintaining pattern integrity.
Implementation Method 1
a polymer comprising recurring units having an acid labile group-substituted carboxyl group, an acid generator
Implementation Method 2
a polymer comprising recurring units (a1) having the general formula (1)... for thereby shrinking the size of spaces in the pattern
Data Source
AI summary
A negative pattern is formed by applying a resist composition onto a substrate, exposing the resist film, and developing the exposed resist film in an organic solvent developer. The process further involves coating the negative pattern with a shrink agent solution of a polymer comprising recurring units capable of forming lactam under the action of acid in a C7-C16 ester or C7-C16 ketone solvent, baking the coating, and removing the excessive shrink agent via organic solvent development for thereby shrinking the size of spaces in the pattern.