Template Substrate Metal Layer Structure for Reduced Warping

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Solution Overview

Problem

Existing semiconductor substrates using MOCVD methods for forming aluminum nitride (AlN) layers face challenges in reducing manufacturing costs and warping due to thermal expansion coefficient differences, which affect the quality and cost-effectiveness of gallium nitride (GaN) layer growth.

Innovation Solution

The use of a thicker metal layer formed by sputtering method on a main substrate, followed by sputtering an aluminum-based nitride layer, reduces warping and improves quality by adjusting internal stress, allowing for efficient and cost-effective production of a template substrate suitable for GaN growth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If MOCVD method is used to form AlN layer, then manufacturing process is established, but warping occurs due to thermal expansion coefficient differences

Engineering Contradiction:
Improvemanufacturing processVSAvoidwarping
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent changes the formation method parameter from MOCVD to sputtering method, and introduces a metal layer with specific thickness (5 nm to 500 nm) to alter the thermal expansion characteristics of the substrate structure, thereby reducing warping while maintaining manufacturability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure by forming a metal layer beneath the AlN layer on the substrate. This composite material structure combines materials with different thermal expansion coefficients to compensate for warping effects during MOCVD processing

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If expensive homogeneous substrate is used, then GaN growth quality is maintained, but manufacturing cost increases

Engineering Contradiction:
ImproveGaN growth qualityVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent introduces a metal layer as an intermediary between the inexpensive heterogeneous substrate and the AlN/GaN layers. This intermediary layer mediates the interface properties to enable high-quality GaN growth on cost-effective substrates

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs an inexpensive heterogeneous substrate (such as silicon or glass) that can be discarded after transferring the GaN structure to the final substrate. This disposable approach reduces manufacturing costs while maintaining product quality

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Ease of manufacture

If thin metal layer is formed, then substrate cost is reduced, but warping control is insufficient

Engineering Contradiction:
Improvesubstrate costVSAvoidwarping control
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent optimizes the metal layer thickness parameter within the range of 5 nm to 500 nm to achieve the right balance between cost reduction and warping control. This parameter optimization allows using thinner, cheaper metal layers while still maintaining adequate warping compensation

Inventive Principle:
Principle #35Parameter changes

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 proposed method enhances the quality of the AlN layer and reduces warping, maintaining the quality of GaN growth while lowering manufacturing costs by using an inexpensive heterogeneous substrate.

Implementation Method 1

forming an aluminum-based nitride layer above the metal layer by using a sputtering method

Methodology Applied
Scientific EffectSputtering: Sputtering

Data Source

PatentEP4607574A1Semiconductor substrate, template substrate, and method and device for producing template substrate
Publication Date: 2025.08.27 KYOCERA CORP
  • EP4607574A1 patent drawingFigure 1~2
  • EP4607574A1 patent drawingFigure 3~4
  • EP4607574A1 patent drawingFigure 5~6

AI summary

A semiconductor substrate includes a template substrate including a first seed region and a growth suppression region, and a first semiconductor part. The first semiconductor part includes a first base located above the first seed region, and a first wing contact to the first base and located above the growth suppression region. The template substrate includes a main substrate, a metal layer located above the main substrate, and an aluminum-based nitride layer located above the metal layer and containing argon. The first semiconductor part includes a nitride semiconductor.