Vapor Deposition Susceptor Alignment via Inclined Grooves

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Solution Overview

Problem

In vapor deposition apparatuses, the expansion and contraction of the susceptor during temperature changes cause misalignment between the susceptor's center and the rotation axis, leading to non-uniform epitaxial film thickness due to positional deviation.

Innovation Solution

The apparatus features disc-shaped susceptors with fitting grooves and projections where the inclined and positioning portions are continuously formed in the radial direction, allowing the susceptor to maintain alignment through self-weight, reducing positional offset during thermal expansion and contraction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a ring-shaped annular groove with arc shape is used to support the susceptor, then the self-weight of the susceptor causes contact portions to move to the bottom of the groove, reducing positional deviation between rotation center and susceptor center, but during temperature changes the susceptor expands and contracts causing the bottom of the groove to shift outward or inward, making the heads come out of the groove and causing misalignment

Engineering Contradiction:

Improvepositional alignment between susceptor center and rotation axisVSAvoidmaintainment of alignment during thermal expansion and contraction

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The fitting groove is designed with an inclined portion that allows the fitting projection to move dynamically in the radial direction in response to thermal expansion and contraction of the susceptor. The inclined surface converts radial movement into circumferential positioning, maintaining proper alignment while accommodating dimensional changes during temperature variations.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The fitting groove structure changes the geometric parameters of the support interface by introducing an inclined portion. This inclined geometry allows the contact point to shift circumferentially as the radial distance changes during thermal expansion, thereby maintaining proper positioning despite parameter changes in the susceptor dimensions.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If the susceptor is supported by fixed heads in an annular groove, then the structure is simple, but thermal expansion and contraction cause the susceptor to deviate from the desired position, resulting in misalignment and non-uniform epitaxial film thickness

Engineering Contradiction:

Improvesimplicity of susceptor support structureVSAvoiduniformity of epitaxial film thickness

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The support structure transitions from a fixed rigid connection to a dynamic adjustable connection. The inclined portion of the fitting groove enables the fitting projection to shift position automatically in response to thermal conditions, maintaining proper alignment without complex active control mechanisms.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The fitting projection automatically adjusts its position within the fitting groove in response to thermal expansion and contraction of the susceptor. The self-weight of the susceptor causes the fitting projection to move along the inclined portion, enabling self-positioning that maintains alignment without external intervention.

Inventive Principle:

Principle #25Self-service

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 ensures consistent alignment of the susceptor with the rotation axis, preventing deviation and achieving uniform epitaxial film thickness across multiple silicon wafers.

Implementation Method 1

the inclined portion and being configured to relatively move corresponding one of the fitting projections with respect to the fitting groove in a circumferential direction of the susceptor with the fitting projection kept in contact by virtue of a self-weight of the susceptor

Methodology Applied

Scientific EffectSelf-weight: Gravitation

Implementation Method 2

expansion and contraction of the susceptor during a process for raising or lowering temperature applied to the susceptor

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS11846039B2Vapor deposition device and method for manufacturing epitaxial silicon wafer

Publication Date: 2023.12.19 SUMCO CORP

AI summary

A vapor deposition apparatus includes a disc-shaped susceptor and a susceptor support member that supports and rotates the susceptor. The susceptor has a plurality of fitting grooves. The susceptor support member is provided with a plurality of support pins to be fitted in the respective plurality of fitting grooves. The fitting grooves each have an inclined portion that relatively moves the support pin with respect to the fitting groove in a circumferential direction of the susceptor with the support pin kept in contact by virtue of a self-weight of the susceptor and a positioning portion that positions the support pin relatively moved by the inclined portion at a specific position in the circumferential direction. The inclined portion and the positioning portion are formed continuously in a radial direction of the susceptor.