Epitaxy Susceptor Guide Elements Reduce Wafer Lifting Pin Friction

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Solution Overview

Problem

Existing devices for handling semiconductor wafers in epitaxy reactors generate particles due to friction between wafer lifting pins and susceptor components, contaminating the wafer and causing tilting issues, especially at varying temperatures.

Innovation Solution

A device with longitudinal holes in the susceptor, wafer lifting pins guided through these holes, and guide sleeves with low-friction guide elements that minimize particle formation by ensuring linear movement and alignment, preventing contamination and tilting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If wafer lifting pins are used to raise and lower the semiconductor wafer, then the wafer can be handled and positioned, but friction between the pins and susceptor components generates particles that contaminate the wafer

Engineering Contradiction:

Improvewafer handling capabilityVSAvoidparticle generation

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent introduces guide elements as intermediary components between the wafer lifting pins and the susceptor. These guide elements with low-friction surfaces mediate the interaction, reducing direct friction and particle generation while still enabling effective wafer handling and positioning.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces high-friction mechanical contact between wafer lifting pins and susceptor components with low-friction guide elements. This substitution reduces the harmful mechanical friction that generates particles, while maintaining the necessary mechanical functionality for wafer handling.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If the device operates in a wide temperature range, then the epitaxy process can be performed at different temperatures, but thermal expansion causes the wafer lifting pins to tilt from vertical position, generating additional particles

Engineering Contradiction:

Improvetemperature range capabilityVSAvoidparticle generation from tilting

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent incorporates thermal expansion compensation into the guide element design. The guide elements are configured to accommodate thermal expansion of the wafer lifting pins at high temperatures, maintaining vertical alignment and preventing tilting that would generate particles.

Inventive Principle:

Principle #37Thermal expansion

Solution Approach 2:

The patent uses parameter changes in the guide element geometry and material properties to compensate for thermal effects. By designing guide elements with specific dimensional parameters and material characteristics, the system maintains proper alignment across a wide temperature range.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If wafer lifting pins are inserted through holes in the susceptor, then the pins can be positioned, but friction between pins and hole surfaces generates particles and causes wear

Engineering Contradiction:

Improvepin positioning accuracyVSAvoidparticle generation from friction

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The guide elements serve as intermediary components between the wafer lifting pins and the susceptor holes. These guide elements provide the necessary positioning function while their low-friction surfaces reduce direct contact friction, thereby minimizing particle generation and wear.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the direct mechanical friction between pins and susceptor hole surfaces with low-friction guide elements. This substitution maintains precise pin positioning while significantly reducing the harmful friction that generates particles and causes wear.

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

The solution effectively reduces particle generation and contamination of the semiconductor wafer, maintaining alignment and minimizing radial play, even at high temperatures, thereby ensuring clean and precise handling of wafers during epitaxial layer deposition.

Implementation Method 1

friction between the wafer lifting pins and the inner surfaces of the holes in the susceptor carrying arms and the through-bores in the susceptor

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

thermal expansion at a high temperature needs to be taken into account

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS11302565B2Device for handling a semiconductor wafer in an epitaxy reactor and method for producing a semiconductor wafer having an epitaxial layer

Publication Date: 2022.04.12 SILTRONIC AG

AI summary

A device for handling a semiconductor wafer in an epitaxy reactor has a susceptor; longitudinal holes extending through the susceptor; a wafer lifting shaft; wafer lifting pins guided through the longitudinal holes; a susceptor carrying shaft; susceptor carrying arms; susceptor support pins; guide sleeves anchored in the susceptor carrying arms; and guide elements protruding from the guide sleeves which, at upper ends, have bores into which wafer lifting pins are inserted, and which can be raised and lowered together with the wafer lifting pins by the wafer lifting shaft.