Phenolic Resin Underlayer Film for Lithography Etching
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Solution Overview
Problem
Current phenolic resins and underlayer films for lithography lack high heat resistance, etching resistance, and solvent solubility, particularly in wet processes like spin coating or screen printing, which are essential for advanced semiconductor manufacturing.
Innovation Solution
A novel phenolic resin is developed by reacting specific phenolic compounds with aldehydes in the presence of an acidic catalyst, resulting in a resin with high carbon concentration, low oxygen concentration, and excellent solvent solubility, suitable for forming underlayer films that can be applied in wet processes and provide high etching resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional phenolic resins are used for underlayer films, then heat resistance is provided, but etching resistance and solvent solubility are insufficient
Solution Approach 1:
The patent modifies the chemical composition parameters of phenolic resins by introducing specific substituents (fluorine, chlorine, sulfur, or nitrogen-containing groups) onto the phenolic ring structure. This parameter change in molecular structure simultaneously enhances etching resistance while maintaining heat resistance and improving solvent solubility, resolving the contradiction between these properties.
Solution Approach 2:
The invention creates a composite resin system by combining modified phenolic resin with specific solvents and optional additives. This composite approach integrates the heat resistance of phenolic resin with improved etching resistance and solvent solubility, achieving a balanced material that satisfies multiple conflicting requirements for underlayer film applications.
2Reliability
If acenaphthene resin is used for antireflective film, then film formation is achieved, but materials are expensive and reaction conditions are stringent
Solution Approach 1:
The patent replaces expensive acenaphthene resin with modified phenolic resin that can be synthesized from readily available phenolic compounds and aldehydes. This substitution uses cheaper, more accessible materials while achieving the same film formation function, significantly reducing material cost and simplifying the manufacturing process.
Solution Approach 2:
The invention changes the chemical parameters of the resin system by using modified phenolic resin with specific substituents, which provides comparable or superior performance to acenaphthene resin but with simpler synthesis conditions, lower cost, and easier manufacturing processes.
3Manufacturing precision
If resist film is made thinner for finer patterns, then resolution is improved, but film thickness becomes insufficient for substrate processing
Solution Approach 1:
The patent divides the protective function into two separate layers: a thin resist film for achieving high-resolution patterning and a thicker underlayer film for providing sufficient protection during substrate processing. The modified phenolic resin in the underlayer layer provides the necessary durability while allowing the resist layer to remain thin for fine pattern formation.
Solution Approach 2:
The invention creates a composite structure consisting of a resist film and an underlayer film made from modified phenolic resin. This composite approach allows each layer to be optimized for its specific function: the resist layer for resolution and the underlayer for processing protection, thereby resolving the contradiction between thin film requirements for resolution and sufficient thickness for processing.
4Reliability
If conventional underlayer films are used, then basic support function is provided, but selection ratio of dry etching rate is not optimized
Solution Approach 1:
The patent modifies the etching rate parameters by introducing specific substituents (fluorine, chlorine, sulfur, or nitrogen-containing groups) into the phenolic resin structure. These parameter changes enable precise control over the etching rate, allowing the underlayer film to provide optimal protection during plasma etching while maintaining its basic support function.
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 novel phenolic resin enables the creation of underlayer films with enhanced heat resistance, solvent solubility, and etching resistance, suitable for advanced semiconductor manufacturing, including finer pattern formation and improved adhesiveness with resist layers.
Implementation Method 1
A resin obtained by reacting a compound represented by formula (1) and/or (2) with an aldehyde represented by formula (3) and/or (4) in the presence of an acidic catalyst
Data Source
AI summary
There is provided a novel phenolic resin which can be used as a coating agent or a resist resin for a semiconductor, which has a high carbon concentration and a low oxygen concentration in the resin, which has a relatively high heat resistance and also a relatively high solvent solubility, and which can be applied to a wet process. There are also provided a material useful for forming a novel photoresist underlayer film which has a relatively high solvent solubility, which can be applied to a wet process, and which is excellent in etching resistance as an underlayer film for a multilayer resist, an underlayer film formed using the same, and a pattern forming method using the same. A resin of the present invention is obtained by reacting a compound having a specified structure and an aldehyde having a specified structure in the presence of an acidic catalyst. In addition, a material for forming an underlayer film for lithography of the present invention includes at least the resin and an organic solvent.