Novel Acid Generator for Chemically Amplified Resist

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Solution Overview

Problem

Onium salt-based acid generators used in chemically amplified resists have low affinity for alkali developing solutions and poor diffusion within resist films, affecting lithography properties like resolution, due to their perfluoroalkylsulfonic acid ions, which are difficult to decompose and pose handling safety concerns.

Innovation Solution

A novel resist composition incorporating an acid generator compound represented by a specific general formula, which includes a hydrocarbon group and an organic cation, enhancing the compound's solubility and diffusion properties, and is produced through a method involving the reaction of specific compounds to form a compound useful as an intermediate for the acid generator.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If onium salt-based acid generators with perfluoroalkylsulfonic acid ions are used, then acid generation capability is maintained, but affinity for alkali developing solutions decreases and diffusion within resist films deteriorates

Engineering Contradiction:

Improveacid generation capabilityVSAvoidaffinity for alkali developing solution and diffusion within resist film

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the chemical parameters of the acid generator by replacing perfluoroalkylsulfonic acid ions with carboxylic acid ions having specific structures (formula 1). This structural parameter change improves both the affinity for alkali developing solutions and diffusion properties while maintaining acid generation capability through careful selection of R1-R6 groups and n value.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite acid generator structure combining organic cations with specific carboxylic acid anions (formula 1). This composite approach integrates the acid-generating cation with the improved-diffusion anion, achieving both reliable acid generation and enhanced solubility/diffusion properties simultaneously.

Inventive Principle:

Principle #40Composite materials

2Reliability

If perfluoroalkylsulfonic acid ions are used in acid generators, then acid generation function is achieved, but decomposition difficulty increases and handling safety deteriorates

Engineering Contradiction:

Improveacid generation functionVSAvoiddecomposition difficulty and handling safety

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameter from perfluoroalkylsulfonic acid ions to carboxylic acid ions with specific molecular structures (formula 1). This parameter change makes the acid generator more easily decomposable and safer to handle while preserving the essential acid generation function through appropriate selection of hydrocarbon groups and structural parameters.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If conventional acid generators are used, then lithography process can proceed, but resolution and pattern shape quality deteriorate

Engineering Contradiction:

Improvelithography process continuityVSAvoidresolution and pattern shape

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent optimizes the molecular structure parameters of the acid generator (formula 1) to achieve better diffusion and solubility characteristics. This parameter optimization enables superior resolution and pattern shape quality while maintaining compatibility with existing lithography processes through appropriate selection of R1-R6 groups and n value.

Inventive Principle:

Principle #35Parameter changes

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 acid generator improves lithography properties by enhancing the solubility and diffusion of the acid within the resist film, leading to better resolution and pattern shape, while minimizing bioaccumulation and improving handling safety.

Implementation Method 1

an acid generator that generates acid upon exposure

Methodology Applied

Scientific EffectPhotoacid generation: Photodissociation

Data Source

PatentEP2073060B1Novel compound and method of producing the same, acid generator, resist composition and method of forming resist pattern

Publication Date: 2016.08.24 TOKYO OHKA KOGYO CO LTD

AI summary

A resist composition including a base component (A) which exhibits changed solubility in an alkali developing solution under action of acid and an acid-generator component (B) which generates acid upon exposure, the acid-generator component (B) including an acid generator (B1) consisting of a compound represented by general formula (b1-1) shown below: wherein Rx represents a hydrocarbon group which may have a substituent exclusive of a nitrogen atom; each of Q2 and Q3 independently represents a single bond or a divalent linkage group; Y1 represents an alkylene group or fluorinated alkyl group of 1 to 4 carbon atoms; and Z+ represents an organic cation exclusive of an ion represented by general formula (w-1).