Cryogenic Pump Geometry and Capture Plates for Ultra-High Vacuum

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Solution Overview

Problem

Achieving ultra-high vacuum conditions in semiconductor manufacturing is challenging due to residual gases and impurities entering the vacuum chamber through surface desorption and permeation, which contaminate products and hinder device performance.

Innovation Solution

The use of a cryogenic pump with a non-cylindrical body shape and movable capture plate modules enhances molecular capture rates by increasing the effective surface area and improving gas molecule trapping efficiency, combined with a radiation device for regeneration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a conventional cylindrical cryogenic pump is used, then the structure is simple and easy to manufacture, but the molecular capture rate is insufficient and escape rates are high

Engineering Contradiction:

Improvemolecular capture rateVSAvoidpump structure complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by transitioning from a conventional cylindrical pump body to a non-cylindrical shape with tapered sides. The sides slope radially outward from the first end to the second end, creating an asymmetric geometry that increases the molecular capture rate by directing gas molecules toward the capture plates while reducing escape rates through the opening.

Inventive Principle:

Principle #4Asymmetry

Solution Approach 2:

The patent introduces a new dimension by adding movable capture plate modules that can move between retracted and extended positions. This dimensional change allows the capture plates to protrude into the pump body, increasing the effective surface area for molecular capture without significantly increasing the overall pump footprint.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Productivity

If the capture plate surface area is increased, then the molecular capture rate improves, but the pump volume and complexity increase

Engineering Contradiction:

Improvemolecular capture rateVSAvoidpump volume

Core Design Contradiction:

ProductivityVSVolume of stationary object

Solution Approach 1:

The patent applies dynamics by making the capture plates movable rather than fixed. The capture plate modules can move between a retracted position (reducing pump volume and complexity) and an extended position (increasing capture surface area and molecular capture rate). This dynamic capability allows the system to optimize performance only when needed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent segments the capture plate structure into multiple movable modules that can be independently controlled. This segmentation allows the system to extend only the necessary capture surface area for achieving ultra-high vacuum conditions, rather than permanently increasing the entire pump structure's volume.

Inventive Principle:

Principle #1Segmentation

3Manufacturing precision

If pressure is reduced to achieve ultra-high vacuum, then product purity improves, but permeation through chamber walls increases

Engineering Contradiction:

Improveproduct purityVSAvoidpermeation rate

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent utilizes phase transitions by employing cryogenic temperatures to condense gas molecules onto the capture plates. The cold header thermally couples to the capture plate modules, causing gas molecules to transition from gas phase to condensed phase on the capture surface, effectively removing them from the vacuum chamber and counteracting permeation effects.

Inventive Principle:

Principle #36Phase transitions

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 configuration significantly improves the efficiency of cryogenic pumps by increasing the molecular capture rate and reducing escape rates, thereby maintaining ultra-high vacuum conditions effectively.

Implementation Method 1

Cryogenic pumps trap particles by condensing the particles on a cold surface

Methodology Applied

Scientific EffectCondensation: Condensation

Implementation Method 2

a cold header thermally coupled to the one or more capture plate modules

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

wherein the body has a non-cylindrical shape with sides sloping radially outward, in relation to the longitudinal axis, in a direction away from the first end and towards the second end

Methodology Applied

Scientific EffectGas molecule trajectory control through geometry: Geometry

Implementation Method 4

one or more movable capture plate modules disposed in the body

Methodology Applied

Scientific EffectAdsorption: Adsorption

Data Source

PatentUS20240337265A1Cryogenic pump for semiconductor processing

Publication Date: 2024.10.10 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Embodiments of the present disclosure provide a cryogenic pump for semiconductor processing, including a body having a flange, configured to be coupled to a process chamber, and an opening defined at a first end of the body; one or more capture plate modules disposed in the body; and a cold header thermally coupled to the one or more capture plate modules. A longitudinal axis of the body is defined from the first end of the body to a second end of the body. A first lateral dimension of the opening is less than a second lateral dimension of the body, the first and second lateral dimensions being defined perpendicular to the longitudinal axis. The second lateral dimension is defined at a position between the opening and the second end.