Photoresist Acid Diffusion Control Agent for Rectangularity and Top Loss

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Solution Overview

Problem

Conventional photoresist compositions fail to achieve superior rectangularity of cross-sectional shape, line width roughness (LWR) performance, resolving ability, and depth of focus, especially with the top loss phenomenon and limited cross-sectional shape improvement.

Innovation Solution

A photoresist composition incorporating a polymer with an acid-labile group, a radiation-sensitive acid generator, and an acid diffusion control agent containing a specific compound that degrades to form a nitrogen-containing group, enhancing acid diffusion control and stability, leading to improved rectangularity, LWR performance, and depth of focus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If conventional acid diffusion control agents are used, then acid diffusion can be controlled to some extent, but the resist pattern exhibits top loss phenomenon and poor rectangularity

Engineering Contradiction:

Improverectangularity of cross-sectional shapeVSAvoidtop loss phenomenon

Core Design Contradiction:

ShapeVSLoss of substance

Solution Approach 1:

The invention changes the chemical parameters of the acid diffusion control agent by using a compound with a specific molecular structure (formula 1) containing a carbonyl group and nitrogen atoms. This structural parameter change enables the compound to effectively control acid diffusion while preventing top loss and improving rectangularity of the resist pattern cross-section.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite photoresist composition by combining the polymer with acid-labile group, radiation-sensitive acid generator, and the specifically structured acid diffusion control agent (formula 1). This composite material approach synergistically improves rectangularity, LWR performance, and depth of focus while preventing top loss.

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If conventional photoresist compositions are used, then basic resist pattern formation is achieved, but line width roughness (LWR) performance and resolving ability are insufficient

Engineering Contradiction:

Improveline width roughness (LWR) performanceVSAvoidresolving ability

Core Design Contradiction:

Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The invention optimizes the photoresist composition parameters by incorporating an acid diffusion control agent with a specifically designed molecular structure (formula 1). This parameter optimization simultaneously improves LWR performance and resolving ability, addressing both manufacturing precision and measurement precision requirements.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If conventional photoresist compositions are used, then processing is possible, but depth of focus and process stability are insufficient

Engineering Contradiction:

Improveprocess stabilityVSAvoiddepth of focus

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The invention develops a composite photoresist composition that integrates the polymer with acid-labile group, radiation-sensitive acid generator, and the specifically structured acid diffusion control agent. This composite formulation enhances both depth of focus and process stability, making the system more reliable for advanced processing.

Inventive Principle:

Principle #40Composite materials

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 photoresist composition exhibits superior rectangularity of cross-sectional shape, reduced LWR, and enhanced resolving ability while maintaining stability and preventing top loss, enabling the formation of high-quality resist patterns for semiconductor devices.

Implementation Method 1

an acid is generated from an acid generating agent upon irradiation with an exposure light such as an ArF excimer laser beam and a KrF excimer laser beam at a light-exposed site

Methodology Applied

Scientific EffectPhotochemical reaction: Photopolymerisation

Implementation Method 2

incorporation of an acid diffusion control agent into the photoresist compositions is employed for the purpose of properly controlling the diffusion of the acid generated from the acid generating agent

Methodology Applied

Scientific EffectAcid diffusion: Diffusion

Implementation Method 3

The carbamate group is degraded by an action of an acid generated from the acid generator and the like upon an exposure, and generates a nitrogen atom-containing group

Methodology Applied

Scientific EffectAcid-catalyzed degradation: Decomposition (biological)

Data Source

PatentUS9557641B2Photoresist composition, resist pattern-forming method, acid diffusion control agent, and compound

Publication Date: 2017.01.31 JSR CORPORATION

AI summary

A photoresist composition containing: a polymer including an acid-labile group; a radiation-sensitive acid generator; and an acid diffusion control agent that contains a compound represented by a formula (1). In the formula (1), R1, R2 and R3 each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. A represents a group having a valency of n that is obtained by combining: a hydrogen atom, a linear hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms or a combination thereof; —O—, —CO—, —COO—, —SO2O—, —NRSO2—, —NRSO2O—, —NRCO— or a combination thereof; and n nitrogen atoms as a binding site to the carbonyl group in the formula (1), in which a sum of atomic masses of the atoms constituting A is no less than 120. n is an integer of 1 to 4.