Dry Vacuum Pump In-Situ Cleaning with Hydrofluoric Acid

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Solution Overview

Problem

In semiconductor manufacturing, dry vacuum pumps suffer from adherent organic residue coatings due to metal organic precursor processes, leading to reduced efficiency and premature wear, as these coatings accumulate and affect the pump's performance.

Innovation Solution

Injecting dilute hydrofluoric acid into the dry pump's inlet when the semiconductor process chamber is idle, allowing the acid to vaporize and interact with and dissolve the organic deposits, which are then removed through the pump's exhaust path.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If metal organic precursor processes are used in semiconductor manufacturing, then semiconductor device fabrication is enabled, but adherent organic residue coatings accumulate on dry pump surfaces

Engineering Contradiction:

Improvesemiconductor device fabricationVSAvoidadherent organic residue coatings

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a chemical cleaning process using hydrofluoric acid to convert the harmful organic residue buildup into a beneficial cleaning action. The acid chemically reacts with and removes the adherent organic coatings that accumulate on pump surfaces, transforming the problem of residue accumulation into a controlled chemical cleaning process that restores pump performance

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the chemical environment within the pump by introducing hydrofluoric acid vapor or liquid during idle periods. This parameter change from a vacuum environment to a chemical cleaning environment enables the removal of organic residues through chemical reaction, allowing the pump to be cleaned in-situ without disassembly

Inventive Principle:

Principle #35Parameter changes

2Productivity

If dry pump operation continues without cleaning, then vacuum processing can proceed, but pump efficiency decreases and wear increases

Engineering Contradiction:

Improvevacuum processing continuityVSAvoidpump efficiency

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements periodic cleaning cycles during idle periods between semiconductor processing runs. Instead of continuous operation without maintenance, the system alternates between processing mode and cleaning mode, allowing organic residues to be removed at regular intervals before they significantly degrade pump performance

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The pump cleaning system is integrated into the pump structure itself, allowing the pump to clean its own internal surfaces without external intervention or disassembly. The hydrofluoric acid is introduced through existing pump ports and circulates through the internal pathways, enabling self-cleaning functionality

Inventive Principle:

Principle #25Self-service

3Ease of manufacture

If traditional cleaning methods are used, then pump disassembly is required, but maintenance time and complexity increase

Engineering Contradiction:

Improvecleaning accessibilityVSAvoidmaintenance time

Core Design Contradiction:

Ease of manufactureVSLoss of time

Solution Approach 1:

The patent uses hydrofluoric acid as an intermediary cleaning agent that can access pump internal surfaces through existing ports without requiring disassembly. The acid acts as a mediator that chemically removes residues from areas that would otherwise require mechanical access, eliminating the need for pump teardown

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces mechanical cleaning methods (which would require disassembly and manual scraping or wiping) with a chemical cleaning system. Hydrofluoric acid vapor or liquid is introduced into the pump and chemically dissolves organic residues, substituting mechanical intervention with chemical action

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

Effectively removes adherent organic and metalorganic deposits from dry vacuum pumps, enhancing their performance and extending their lifespan by preventing premature wear and failure, while being cost-effective and reducing maintenance needs.

Implementation Method 1

allowing the acid to vaporize and interact with and dissolve the organic deposits

Methodology Applied

Scientific EffectChemical dissolution: Solvation

Implementation Method 2

allowing the acid to vaporize and interact with and dissolve the organic deposits

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS8636019B2In-situ removal of semiconductor process residues from dry pump surfaces

Publication Date: 2014.01.28 EDWARDS VACUUM LLC

AI summary

The present invention relates to vacuum processing systems in which process gases are introduced in a process chamber and are exhausted through a vacuum processing system exhaust path. Deposits made by the exhausted gases in one or more dry vacuum pumps are removed by introducing hydrofluoric acid upstream of the dry pump while the processing chamber is idle. The hydrofluoric acid is introduced upstream of the dry pump through a nozzle in the foreline or at the inlet to the dry pump.