Lithography Copolymer Composition Control for Pattern Rectangularity
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Solution Overview
Problem
In semiconductor lithography, controlling the composition of hydroxyl group-containing repeating units in copolymers is challenging, leading to issues with pattern shape and integration density, as existing methods either lower or raise the composition in the low molecular weight region, affecting pattern rectangularity and integration density.
Innovation Solution
A copolymer for semiconductor lithography is developed by controlling the molar composition of hydroxyl group-containing repeating units in the low molecular weight region within ±10% of the average, using a combination of polar and nonpolar solvents for reprecipitation and washing to refine the copolymer, ensuring accurate pattern formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the composition of hydroxyl group-containing repeating units in the low molecular weight region is not controlled, then the manufacturing process is simpler, but the pattern rectangularity and integration density deteriorate
Solution Approach 1:
The invention controls the composition of hydroxyl group-containing repeating units in the low molecular weight region (specifically, the molar composition ratio is set to 0.85-1.15 times the average molar composition) to achieve excellent pattern rectangularity and integration density. This parameter control resolves the contradiction by establishing a specific compositional range that optimizes lithographic performance.
Solution Approach 2:
The invention applies local quality control by specifically managing the composition in the low molecular weight region (5% area in GPC) separately from the overall average composition. This localized compositional control ensures that the low molecular weight fraction, which significantly affects pattern shape, has the appropriate hydroxyl group content for optimal performance.
2Strength
If the composition of hydroxyl group-containing repeating units in the low molecular weight region is increased, then the adhesiveness to substrate improves, but the pattern shape rectangularity deteriorates
Solution Approach 1:
The invention establishes an optimal parameter range for the molar composition ratio of hydroxyl group-containing repeating units in the low molecular weight region (0.85-1.15 times the average). This balanced compositional control ensures sufficient adhesiveness while maintaining excellent pattern rectangularity, resolving the contradiction between these two properties.
3Stability of the object's composition
If the composition of hydroxyl group-containing repeating units in the low molecular weight region is decreased, then the solubility control improves, but the integration density deteriorates
Solution Approach 1:
The invention optimizes the molar composition ratio of hydroxyl group-containing repeating units in the low molecular weight region to 0.85-1.15 times the average molar composition. This controlled composition achieves both good solubility characteristics and high integration density, resolving the contradiction between these two requirements.
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 enables the formation of a fine pattern with excellent rectangularity, allowing for dense and integrated circuits by maintaining the desired composition of hydroxyl group-containing units, thus improving processing accuracy and yield.
Implementation Method 1
formation of a resist pattern for transferring on a substrate is formed, in which by making use of a variation of the solubility to an alkali developer under an action of acid
Implementation Method 2
the coating solution is coated on a substrate according to a method such as a spin coating method
Implementation Method 3
as needs arise the solvent is removed by heating or the like
Data Source
AI summary
In order to improve a resist pattern shape in a semiconductor lithography process, which is a factor largely affecting on a processing precision, an integration degree and yield, a copolymer for semiconductor lithography where a composition of a hydroxyl group-containing repeating unit in a low molecular weight region is controlled, and a method of producing the same are provided.According to the invention, in a copolymer for semiconductor lithography, which is obtained by copolymerizing a monomer having a hydroxyl group and a monomer having no hydroxyl group, when a copolymer of which composition of a hydroxyl group-containing repeating unit is controlled is used, the object can be achieved.