TEAH Developer Composition for EUV Lithography Pattern Collapse

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Solution Overview

Problem

EUV lithography faces challenges in forming desired micropatterns due to carbon atom absorption, leading to pattern collapse and reduced sensitivity, which results in low productivity and non-uniform patterns.

Innovation Solution

A developer composition containing 2 to 10 wt % tetraethylammonium hydroxide (TEAH) is used to reduce the energy of optimum (Eop) during developing, preventing pattern collapse and enhancing pattern uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If carbon atoms are absorbed in a small amount during EUV exposure, then sensitivity to EUV is reduced, but increasing carbon absorption causes pattern collapse

Engineering Contradiction:
Improvepattern formation reliabilityVSAvoidthroughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the chemical composition parameters of the developer by using tetraethylammonium hydroxide (TEAH) with a specific concentration range (2-10 wt%, preferably 4-8 wt%). This parameter change in the developer composition enables effective development at lower EUV doses, improving throughput while maintaining pattern formation reliability through optimized chemical properties of the developer

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the dose required for developing is reduced to improve throughput, then productivity increases, but pattern uniformity deteriorates

Engineering Contradiction:
ImprovethroughputVSAvoidpattern uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent employs parameter changes by optimizing the developer composition with tetraethylammonium hydroxide at specific concentrations (2-10 wt%). This enables effective pattern development at reduced EUV doses while maintaining excellent pattern uniformity, thereby improving throughput without sacrificing manufacturing precision

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite developer composition containing tetraethylammonium hydroxide combined with water in specific proportions. This composite material provides enhanced developing capability that achieves uniform pattern formation at lower doses, simultaneously improving productivity and maintaining pattern uniformity

Inventive Principle:
Principle #40Composite materials

3Reliability

If conventional developers (TMAH or TBAH) are used, then pattern development is achieved, but Eop is high causing pattern collapse and low productivity

Engineering Contradiction:
Improvepattern development effectivenessVSAvoidthroughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the chemical parameter of the developer by substituting conventional TMAH or TBAH with tetraethylammonium hydroxide (TEAH) at optimized concentrations (2-10 wt%). This parameter change reduces the Eop significantly, enabling effective pattern development with lower EUV exposure energy, thereby improving throughput while maintaining pattern development effectiveness

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a disposable developer composition with tetraethylammonium hydroxide that is optimized for single-use effectiveness. This developer provides high developing efficiency at low Eop, allowing rapid processing and improved throughput without the need for complex reconditioning or recycling processes

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Data Source

PatentUS11199779B2Developer composition, for EUV light source, for forming photosensitive photoresist micropattern
Publication Date: 2021.12.14 YOUNG CHANG CHEMICAL CO LTD

AI summary

A photoresist developer composition for an EUV (extreme ultraviolet) light source in a semiconductor-manufacturing process is proposed. Further, the photoresist developer composition for an EUV light source for forming a micropattern and a lithography process of forming a pattern on a semiconductor substrate using an EUV light source using the composition are proposed. The composition includes an aqueous solution containing 2 to 10 wt % of tetraethylammonium hydroxide (TEAH). When a photoresist is developed, an Eop is reduced, which shortens a process time, prevents a pattern from collapsing, and enables a pattern to have a uniform profile.