Lithography Ammonia Byproduct Removal for Photoresist Resolution

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Solution Overview

Problem

During semiconductor manufacturing, ammonia gas by-products generated from alkaline-based developers in lithography processes can lead to scum formation and deteriorate development resolution, affecting product yield and pattern fidelity.

Innovation Solution

A method involving the removal and monitoring of ammonia gas by-products using a treating tool with adsorptive materials and an ammonia gas monitor within the lithography tool, ensuring the concentration remains below a threshold to prevent adverse reactions and improve processing outcomes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If ammonia gas by-products are not removed from the lithography tool, then the development process can proceed without interruption, but scum formation occurs and development resolution deteriorates

Engineering Contradiction:

Improvedevelopment resolutionVSAvoidlithography tool structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

A treating tool is introduced as an intermediary component between the development unit and the environment. This treating tool contains adsorptive materials that capture ammonia gas by-products, preventing them from causing scum formation while allowing the development process to continue uninterrupted. The intermediary device resolves the contradiction by adding controlled complexity only where needed to remove harmful by-products.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The treating tool creates a controlled environment by adsorbing ammonia gas, effectively removing the harmful reactive component from the atmosphere within the lithography tool. This establishes an inert-like environment regarding ammonia reactions, preventing scum formation while maintaining normal development operations.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

2Reliability

If a treating tool with adsorptive materials is added to remove ammonia gas, then scum formation is prevented and development resolution is improved, but the device complexity increases

Engineering Contradiction:

Improvepattern fidelityVSAvoidlithography tool structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The treating tool serves as a dedicated intermediary subsystem that handles ammonia removal independently. By separating the ammonia removal function from the core development process, the system achieves improved reliability and pattern fidelity while containing the added complexity to a specific auxiliary component rather than complicating the entire lithography tool.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The treating tool is designed to capture and retain ammonia gas by-products through adsorption, effectively discarding the harmful substance from the process environment. The adsorptive materials are positioned to continuously absorb ammonia, maintaining reliable operation while the spent adsorbents can be periodically replaced or regenerated.

Inventive Principle:

Principle #34Discarding and recovering

3Productivity

If the concentration of ammonia gas by-products is not monitored, then the processing continues without interruption, but scum formation deteriorates product yield

Engineering Contradiction:

Improveproduct yieldVSAvoidammonia gas concentration monitoring

Core Design Contradiction:

ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

An ammonia gas monitor is implemented to provide real-time feedback on ammonia concentration levels within the lithography tool. This feedback mechanism triggers alerts or automated responses when ammonia reaches critical thresholds, enabling timely intervention to prevent scum formation and maintain high product yield. The monitoring system converts the difficult-to-detect ammonia presence into actionable information.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The monitoring of ammonia gas concentration, which is chemically complex and difficult to detect directly, is replaced by using sensitive detection instruments that convert chemical concentration measurements into readable signals. This substitution makes the detection and measurement of ammonia levels practical and integrated into the automated lithography process.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This approach effectively reduces the concentration of ammonia gas by-products, preventing scum formation and enhancing development resolution and pattern fidelity, leading to higher semiconductor device yields.

Implementation Method 1

A method involving the removal and monitoring of ammonia gas by-products using a treating tool with adsorptive materials

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 2

an ammonia gas monitor within the lithography tool, ensuring the concentration remains below a threshold

Methodology Applied

Scientific EffectGas detection:

Data Source

PatentUS11899368B2Manufacturing method of semiconductor device and semiconductor processing system

Publication Date: 2024.02.13 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A method of manufacturing a semiconductor device is as below. An exposed photoresist layer is developed using a developer supplied by a developer supplying unit. An ammonia gas by-product of the developer is discharged through a gas outlet of the developer supplying unit into a treating tool. The ammonia gas by-product is retained in the treating tool. A concentration of the ammonia gas by-product is monitored.