Polymer Resist Composition for High-Resolution Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current positive resist compositions face challenges in achieving high sensitivity, resolution, and minimal edge roughness for microelectronic device manufacturing, particularly as feature sizes decrease, due to issues with acid diffusion and film thickness loss during exposure processes.
Innovation Solution
A polymer comprising recurring units of butyrolactone (meth)acrylate, carboxyl or phenolic groups with acid labile substitutions, and hydroxy-aromatic groups or 2,2,2-trifluoro-1-hydroxyethyl groups is developed, which improves dissolution contrast, suppresses acid diffusion, and maintains film thickness, forming a resist composition suitable for high-resolution patterning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the accelerating voltage of the electron gun is increased to enable further size reduction, then the resolution and dimensional control are improved, but the sensitivity of the resist film decreases
Solution Approach 1:
The patent changes the chemical composition parameters of the resist film by incorporating specific polymer structures (poly-4-hydroxystyrene with controlled molecular weight and composition) to optimize the balance between sensitivity and resolution at high accelerating voltages
Solution Approach 2:
The patent uses composite resist formulations combining poly-4-hydroxystyrene base polymer with specific additives and modifiers to achieve both high sensitivity and high resolution performance simultaneously
2Manufacturing precision
If acid diffusion is suppressed to improve resolution for fine patterns, then the resolution is improved, but the sensitivity decreases
Solution Approach 1:
The patent introduces local quality control by incorporating specific functional groups at controlled positions within the polymer structure to create localized acid generation zones that limit diffusion while maintaining overall sensitivity
Solution Approach 2:
The patent optimizes the molecular weight and composition parameters of the poly-4-hydroxystyrene to control acid diffusion distance while preserving sensitivity through careful parameter selection
3Manufacturing precision
If the exposure dose is increased to reduce edge roughness, then the edge roughness is reduced, but the sensitivity decreases
Solution Approach 1:
The patent changes the chemical structure parameters of the resist polymer to intrinsically reduce edge roughness through controlled molecular architecture, eliminating the need for high exposure doses
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 polymer-based resist composition achieves high resolution and minimal edge roughness, preventing pattern collapse and film thickness loss, making it suitable for advanced lithography processes such as ArF, KrF, EUV, and EB lithography for microfabrication of VLSI and photomasks.
Implementation Method 1
the exposure system for mask manufacturing made a transition from the laser beam exposure system to the EB exposure system
Implementation Method 2
image blurs due to acid diffusion become a problem
Implementation Method 3
chemically amplified resist compositions are contemplated
Data Source
AI summary
A polymer comprising recurring units of butyrolactone (meth)acrylate, recurring units having a carboxyl or phenolic group which is substituted with an acid labile group, and recurring units having a phenol group or an adhesive group in the form of 2,2,2-trifluoro-1-hydroxyethyl is quite effective as a base resin for resist. A positive resist composition comprising the polymer is improved in such properties as a contrast of alkali dissolution rate before and after exposure, acid diffusion suppressing effect, resolution, and profile and edge roughness of a pattern after exposure.