Resist Composition Preventing Pattern Collapse in Semiconductor Lithography

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Solution Overview

Problem

In the process of forming fine patterns on substrates for semiconductor elements, the negative type development process faces issues with pattern collapse and reduction in film thickness due to uneven light intensity distribution during exposure, leading to etching defects.

Innovation Solution

A resist composition is developed that includes a polymer compound with specific constitutional units, which generates an acid upon exposure, changing its solubility in a developer, thereby preventing pattern collapse and ensuring an excellent shape of the resist pattern.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If negative type development process is used, then fine patterns can be formed, but pattern collapse and film thickness reduction occur due to uneven light intensity distribution

Engineering Contradiction:

Improvefine pattern formationVSAvoidpattern collapse

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the resist composition by incorporating specific base material components with carboxyl groups and controlling the ratio of acid-generating components. This modifies the chemical reactions during exposure and development to reduce the harmful effects of uneven light intensity distribution, preventing pattern collapse while maintaining fine pattern formation capability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite resist composition containing multiple components: base material (polymer with carboxyl groups), acid generator, and specific additives. This composite structure allows the resist to function effectively in negative type development while compensating for the uneven light intensity distribution through synergistic interactions between components, thereby preventing pattern collapse.

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If negative type development process is used, then fine patterns can be formed, but etching defects occur due to film thickness reduction

Engineering Contradiction:

Improvefine pattern formationVSAvoidetching defects

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the chemical composition parameters to include base material with specific carboxyl group content and controls the acid generator ratio. This changes the development behavior to maintain more uniform film thickness across the pattern, eliminating the film thickness reduction that causes etching defects while preserving fine pattern formation.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If chemically amplified resist composition is used, then lithography characteristics are improved, but pattern collapse occurs in negative type development

Engineering Contradiction:

Improvelithography characteristicsVSAvoidpattern collapse

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent creates a specialized chemically amplified resist composition with a composite structure including base material containing carboxyl groups, acid generator, and specific additives in controlled ratios. This composite formulation maintains the high lithography characteristics of chemically amplified resists while the specific component interactions prevent pattern collapse during negative type development.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent adjusts the chemical parameters of the chemically amplified resist by controlling the carboxyl group content in the base material and the ratio of acid-generating components. This parameter optimization allows the resist to achieve excellent lithography characteristics while preventing the pattern collapse that typically occurs in negative type development processes.

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 resist composition effectively suppresses pattern collapse and film thickness reduction, improving the quality of the resist pattern and reducing etching defects by maintaining the integrity of the pattern shape during the development process.

Implementation Method 1

an acid generator component that generates an acid when exposed

Methodology Applied

Scientific EffectPhotochemical reaction: Photopolymerisation

Data Source

PatentUS10921711B2Resist composition and method of forming resist pattern

Publication Date: 2021.02.16 TOKYO OHKA KOGYO CO LTD

AI summary

A resist composition which generates an acid when exposed and whose solubility in a developer is changed by an action of an acid, the resist composition including: a base material component (A) whose solubility in a developer is changed by an action of an acid, in which the base material component (A) comprises a polymer compound (A1) having a constitutional unit (a01) represented by Formula (a0-1), a constitutional unit (a02) represented by Formula (a0-2), and a constitutional unit (a03) which is represented by Formula (a0-3) and has a structure different from the constitutional unit (a02).