Hydrophobic Coating for CVD Pump Internal Surfaces

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Solution Overview

Problem

Semiconductor wafer fabrication processes result in gases with reactive compounds and residues that deposit in vacuum pumps, causing clogs and contamination, leading to reduced pump efficiency and wafer yield, with existing cleaning methods requiring shutdown and being ineffective for continuous maintenance.

Innovation Solution

Applying a hydrophobic coating to the internal surfaces of pumping devices and lines to repel water and residues, preventing deposition and allowing for continuous operation without frequent shutdowns, using materials like fluorinated polymers in Hydrofluoroether solvents and ensuring the coating does not chemically react with processed gases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If periodic cleaning of the pump is performed, then deposits are removed, but the wafer processing system must be shut down, reducing efficiency

Engineering Contradiction:

Improvepump operation continuityVSAvoidwafer processing efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by coating the internal surfaces of the pump and piping with hydrophobic material before the deposition process begins. This preventive coating stops polymer deposits from adhering to surfaces in the first place, eliminating the need for periodic shutdowns to clean the pump while maintaining continuous wafer processing operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent converts the harmful effect of water condensation from a problem into a benefit. By applying hydrophobic coating, the condensed water is repelled and blown out of the pump with the gas flow, transforming what would normally be a harmful condensation issue into a mechanism that prevents polymer deposition and keeps the pump clean during continuous operation.

Inventive Principle:

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

2Reliability

If cleaning methods are used to remove deposits, then pump performance is maintained, but maintenance time increases and system downtime occurs

Engineering Contradiction:

Improvepump performanceVSAvoidmaintenance shutdown time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The hydrophobic coating is applied in advance to prevent polymer deposits from forming on pump surfaces. This preliminary protective action eliminates the need for future cleaning operations, maintaining pump performance continuously without requiring shutdowns for maintenance.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The coating enables the pump system to maintain itself by using the gas flow and condensed water to continuously blow off any potential deposits from the hydrophobic surfaces. This self-cleaning mechanism eliminates the need for external intervention and scheduled maintenance downtime.

Inventive Principle:

Principle #25Self-service

3Device complexity

If no coating is applied to pumping surfaces, then the system is simpler, but polymer deposits clog the pump and pumping lines

Engineering Contradiction:

Improvepumping system structureVSAvoidpump clog prevention

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent changes the surface energy parameter of the pump interior surfaces by applying a hydrophobic coating. This parameter change modifies the interaction between condensed water and the surfaces, causing water to be repelled and blown off rather than adhering, thereby preventing polymer deposit formation without significantly increasing system complexity.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining the existing pump structure with a hydrophobic coating layer. This composite approach maintains the original pump design while adding the protective coating property, preventing clogs without requiring a completely different pump design.

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 hydrophobic coating effectively prevents polymer deposition, maintaining pumping speed and reducing maintenance needs, thereby extending the life of the pumping system and minimizing wafer contamination and processing defects.

Implementation Method 1

The coating can make the internal surface hydrophobic... the coated internal surface has a hydrophobic effect that would repel liquid drops condensed from the gases

Methodology Applied

Scientific EffectHydrophobic effect: Hydrophobe

Implementation Method 2

the coated internal surface has a hydrophobic effect that would repel liquid drops condensed from the gases passing through the pumping device

Methodology Applied

Scientific EffectSurface tension: Surface Tension

Data Source

PatentUS11155916B2Apparatus and methods for pumping gases from a chamber

Publication Date: 2021.10.26 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Apparatus and methods for pumping gases from a chamber are disclosed. In one example, an apparatus for evacuating gases from a chemical vapor deposition (CVD) chamber is disclosed. The apparatus includes: a housing including an internal surface and at least one inlet in fluid communication with the CVD chamber; and a coating on the internal surface. The coating is configured to make the internal surface hydrophobic.