Acoustic Wave Filter Purging for Semiconductor Manufacturing

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Solution Overview

Problem

In photolithography processes, filters used in semiconductor manufacturing often retain air bubbles due to surface tension, leading to inefficiencies in qualification processes, fluid wastage, and tool unavailability for production, as conventional methods require prolonged purging to remove bubbles, causing delays and increased costs.

Innovation Solution

An acoustic wave generator is integrated with the filter housing to apply ultrasonic or megasonic energy, effectively disengaging bubbles from the filter media, allowing for quicker qualification and reducing fluid wastage by automatically detecting bubble-free conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If continuous purging is performed to remove bubbles from the filter, then the filter quality is improved, but the time required and fluid waste increase significantly

Engineering Contradiction:

Improvefilter qualityVSAvoidpurging time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies ultrasonic vibration to the filter media to disrupt and remove air bubbles. The ultrasonic waves create mechanical oscillations that break the surface tension holding bubbles in the porous filter structure, causing them to coalesce and drain away, thereby eliminating the need for extended continuous purging.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The patent replaces the conventional mechanical purging system (relying on gravity and time for bubbles to naturally escape) with an acoustic field-based system. The ultrasonic transducer generates acoustic waves that directly act on the bubbles, providing a much faster and more efficient removal mechanism.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If continuous purging is performed to remove bubbles from the filter, then the filter quality is improved, but the fluid waste increases significantly

Engineering Contradiction:

Improvefilter qualityVSAvoidfluid waste

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The ultrasonic vibration rapidly removes bubbles from the filter, significantly reducing the volume of fluid that needs to be purged through the filter. This minimizes the waste of expensive photolithography fluids while ensuring the filter is properly saturated and free of bubbles for production use.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The ultrasonic purging is performed as a preliminary action before production runs, quickly preparing the filter for use. This preliminary treatment removes the bulk of bubbles efficiently, reducing the subsequent fluid waste that would occur during extended conventional purging.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If conventional purging methods are used, then bubbles are eventually removed, but the tool availability is reduced

Engineering Contradiction:

Improvebubble removalVSAvoidtool availability

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The ultrasonic purging system rapidly removes bubbles from the filter, reducing the time the tool is unavailable for production. The acoustic waves quickly disrupt and remove bubbles, allowing the filter to be qualified for production use much faster than conventional methods, thereby improving tool availability and productivity.

Inventive Principle:

Principle #18Mechanical vibration

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 integration of an acoustic wave generator significantly reduces the time required to remove bubbles from filters, enhancing filter readiness for production use, minimizing fluid wastage, and reducing downtime of manufacturing tools, thereby improving operational efficiency and cost-effectiveness.

Implementation Method 1

An acoustic wave generator is used to apply ultrasonic or megasonic energy to the filter, quickly disengaging bubbles

Methodology Applied

Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Implementation Method 2

acoustic wave generator contacting the housing and capable of applying acoustic energy to the porous filter media

Methodology Applied

Scientific EffectAcoustic cavitation: Acoustic Cavitation

Data Source

PatentUS9480938B2Method for using acoustic waves for purging filters in semiconductor manufacturing equipment

Publication Date: 2016.11.01 TSMC WASHINGTON LLC

AI summary

An apparatus and method for qualifying a filter used to filter fluid used in a coating operation associated with photolithography or other semiconductor manufacturing processes, provides a semiconductor manufacturing tool that includes a filter and an acoustic wave generator. The filter may be housed inside a filter housing and the acoustic wave generator may produce ultrasonic, megasonic or other acoustic energy. The acoustic wave generator contacts or is in close proximity with the filter housing and provides acoustic wave energy to the filter through the housing. The acoustic wave energy causes any bubbles in the filter to become disengaged.