Amine Quencher Resist Composition for LWR and CDU Control

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Solution Overview

Problem

Current chemically amplified resist compositions face challenges in achieving high sensitivity, low line width roughness (LWR), and improved critical dimension uniformity (CDU) due to limitations in acid diffusion control and light contrast, especially as pattern feature sizes approach the diffraction limit of light.

Innovation Solution

A chemically amplified resist composition incorporating an amine compound with a highly polar ring structure and acid labile group is developed, which acts as a quencher to reduce acid diffusion and enhance contrast, thereby improving sensitivity and CDU.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional quenchers (sulfonium or iodonium salts) are used to control acid diffusion, then acid diffusion control is improved, but the quencher absorbs ArF radiation and reduces light transmittance, leading to tapered pattern profiles in thick resist films

Engineering Contradiction:

Improveacid diffusion controlVSAvoidlight transmittance

Core Design Contradiction:

Manufacturing precisionVSIllumination intensity

Solution Approach 1:

The patent changes the chemical structure of the quencher from sulfonium/iodonium salts to amine compounds with specific structures (formula 1), which have different optical properties. This structural parameter change allows the quencher to control acid diffusion while being transparent to ArF radiation, resolving the contradiction between acid diffusion control and light transmittance.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite approach by combining the amine compound quencher with specific photoacid generators and resist polymers. This composite resist composition achieves both effective acid diffusion control and high light transmittance, overcoming the limitations of conventional single-component quenchers.

Inventive Principle:

Principle #40Composite materials

2Productivity

If pattern feature size is reduced to increase integration density, then manufacturing capacity is improved, but light contrast lowers, reducing resolution and focus margin

Engineering Contradiction:

Improveintegration densityVSAvoidresolution

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the chemical composition parameters of the resist system by introducing amine compound quenchers with specific molecular structures (formula 1). This changes the acid-quencher interaction parameters, leading to sharper contrast and improved resolution that enables patterning at reduced feature sizes without sacrificing manufacturing precision.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The amine compound acts as an intermediary between the photoacid generator and the resist polymer. It mediates the acid diffusion process by providing optimal quenching efficiency, which enhances the contrast transfer from the exposure pattern to the developed pattern, thereby maintaining resolution at smaller feature sizes.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Strength

If resist film thickness is increased to accommodate thicker hard masks in 3D-NAND, then etch selectivity is improved, but dissolution contrast decreases, reducing pattern resolution

Engineering Contradiction:

Improveetch selectivityVSAvoiddissolution contrast

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The patent changes the chemical parameters of the resist system by incorporating amine compound quenchers that provide optimal acid quenching in thick resist films. This changes the dissolution kinetics parameters, maintaining high dissolution contrast even in 100nm or thicker resist films, thereby preserving pattern resolution while enabling etch selectivity through increased film thickness.

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 amine compound effectively reduces LWR and improves CDU by controlling acid diffusion and increasing contrast, resulting in high-resolution patterns with wider process margins.

Implementation Method 1

Quenchers (or acid diffusion controlling agents) are often added to these resist compositions for the purpose of controlling the diffusion of the acid to unexposed region to improve the contrast

Methodology Applied

Scientific EffectAcid diffusion control: Diffusion

Implementation Method 2

Chemically amplified resist compositions comprising an acid generator capable of generating an acid upon exposure to light

Methodology Applied

Scientific EffectPhotochemical reaction: Photodissociation

Implementation Method 3

chemically amplified positive resist compositions wherein deprotection reaction takes place under the action of acid

Methodology Applied

Scientific EffectAcid-catalyzed deprotection reaction: Hydrolysis

Data Source

PatentUS20230134822A1Amine compound, chemically amplified resist composition, and patterning process

Publication Date: 2023.05.04 SHIN ETSU CHEMICAL CO LTD

AI summary

A resist composition comprising a quencher in the form of an amine compound having a highly polar lactone or sultone ring and an acid labile group in a common molecule is provided. The resist composition has a high sensitivity and forms a pattern with improved LWR or CDU, independent of whether it is of positive or negative tone.