Segmented Graphite Disc Structure for Uniform Epitaxial Wafers

Solution Overview

Problem

The performance uniformity of epitaxial wafers obtained through metal-organic chemical vapor deposition using conventional graphite discs is poor, with issues such as uneven wavelength and thick edges due to gas flow impacts during the epitaxial growth process.

Innovation Solution

A graphite disc with a groove divided into multiple interconnected regions by projections, which enhances gas flow space and improves substrate fixation, featuring smooth side walls, through-holes, and optimized heat dissipation to ensure uniform epitaxial growth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional graphite disc with one groove corresponding to one substrate is used, then the structure is simple, but the performance uniformity of the epitaxial wafer is poor with thick edges

Engineering Contradiction:

Improveperformance uniformity of epitaxial waferVSAvoidgraphite disc structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The groove is divided into multiple independent regions by projections, with each region corresponding to one substrate. This segmentation allows independent control of gas flow and temperature for each substrate, improving performance uniformity while preventing edge thickening through better gas distribution.

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If the groove is divided into multiple regions by projections, then gas flow space is enlarged improving uniformity, but the device structure becomes more complex

Engineering Contradiction:

Improveuniformity of epitaxial waferVSAvoidgroove structure with projections

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The groove is divided into multiple independent regions by projections, with each region corresponding to one substrate. This segmentation allows independent control of gas flow and temperature for each substrate, improving performance uniformity while preventing edge thickening through better gas distribution.

Inventive Principle:

Principle #1Segmentation

3Reliability

If arc segments are used for the edge of the groove projection, then substrate fixation is improved, but the manufacturing process becomes more complex

Engineering Contradiction:

Improvesubstrate fixationVSAvoidgroove preparation process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The edge of the orthographic projection of the groove includes arc segments that match the curvature of the substrate edges. This curved design improves substrate fixation and alignment during rotation, while the arc segments can be manufactured using standard CNC machining or electrical discharge machining techniques.

Inventive Principle:

Principle #14Spheroidality (Curvature)

4Ease of manufacture

If straight-line segments connect arc segments in the groove edge, then the etching path is shortened simplifying manufacturing, but the substrate fixation may be compromised

Engineering Contradiction:

Improveetching path lengthVSAvoidsubstrate fixation

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The edge of the orthographic projection of the groove includes arc segments that match the curvature of the substrate edges. This curved design improves substrate fixation and alignment during rotation, while the arc segments can be manufactured using standard CNC machining or electrical discharge machining techniques.

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 alleviates the issue of thick edges and enhances uniformity by increasing gas flow space, improving substrate fixation, and optimizing heat distribution, resulting in more uniform epitaxial wafer performance.

Implementation Method 1

heat is transferred through the graphite disc body during an epitaxial growth process

Methodology Applied

Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

cooperatively injecting metal-organic compounds and V-group gases so that chemical bonds of the metal-organic compounds and V-group gases may be broken and re-polymerized to form an LED epitaxial layer on the substrate

Methodology Applied

Scientific EffectChemical vapor deposition: Chemical Vapour Deposition

Data Source

PatentUS12494392B2Graphite disc

Publication Date: 2025.12.09 ENKRIS SEMICON

AI summary

Disclosed is a graphite disc solving a problem of poor performance uniformity of the epitaxial wafer, which is obtained during material epitaxial growth by using the graphite disc. The graphite disc includes a graphite disc body, where the graphite disc body includes a groove and a plurality of projections on a bottom wall of the groove, and the plurality of projections divide the groove into a plurality of independent regions. According to the graphite disc provided by the present disclosure, a plurality of regions are defined in the groove by using the projections, each region corresponds to one substrate, and different regions are interconnected. Compared with the graphite disc structure with one groove corresponding to one substrate in the related art, a space for gas flow is enlarged, therefore a problem that an edge of the epitaxial wafer is too thick caused by gas flow is alleviated.