Negative Resist Composition for Isolated Contact Hole DOF
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Solution Overview
Problem
Current resist compositions for forming isolated-contact-hole patterns in semiconductor production face limitations in depth of focus margin (DOF), which affects the precision and reliability of pattern formation.
Innovation Solution
A resist composition comprising a specific acid-decomposable resin and photoacid generator, with a resin structure that includes repeating units and compounds designed to enhance solubility and etching resistance, and a development process using a developer with an organic solvent to improve DOF.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional positive resist composition with alkali developer is used, then sensitivity and resolution are improved, but depth of focus margin (DOF) in isolated-contact-hole pattern formation deteriorates
Solution Approach 1:
The patent inverts the conventional approach by using a negative resist composition with organic solvent developer instead of positive resist with alkali developer. This inversion allows the resist to maintain solubility in organic solvents while achieving acid-decomposability through specific resin structures (formulae I-a, I-b, and II), thereby improving DOF in isolated-contact-hole patterns while maintaining pattern formation precision
Solution Approach 2:
The patent employs composite material design by combining specific acid-decomposable resin structures (formulae I-a, I-b, and II) with photoacid generators (formulae III-a and III-b) to create a novel negative resist composition. This composite approach enables simultaneous achievement of organic solvent solubility and acid-decomposability, resolving the contradiction between pattern precision and depth of focus margin
2Reliability
If negative resist composition with organic solvent developer is used, then depth of focus margin is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies parameter changes by carefully controlling the molecular weight (5,000-30,000), composition ratios (formulae I-a: 10-50 mol%, I-b: 10-50 mol%, II: 20-80 mol%), and structural parameters of the resin components. These parameter optimizations simplify the manufacturing process while maintaining the improved depth of focus margin characteristic
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 composition significantly enhances the depth of focus margin in forming isolated-contact-hole patterns, leading to improved pattern formation precision and reliability.
Implementation Method 1
any of compounds (B) of general formulae (III-a) and (III-b) below, wherein the compound (B) is a photoacid generator
Implementation Method 2
a resin (A) which contains any of repeating units (a) of general formulae (I-a) and (I-b) below and any of repeating units (b) of general formula (II) below, and when acted on by an acid, is decomposed
Data Source
AI summary
A resist composition includes a resin (A) containing any of repeating units (a) of general formulae (I-a) and (I-b) below and any of repeating units (b) of general formula (II) below but containing substantially no repeating unit in which an alcoholic hydroxyl group is introduced, and any of compounds (B) of general formulae (III-a) and (III-b) below.