Nitride Stack Regrowth with Oxide Surface Protection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The regrowth of a second group III nitride on a first group III nitride is adversely affected by impurities adhered to the surface of the first group III nitride when unloaded from the depositing apparatus, leading to issues such as high resistance and leakage current due to impurity contamination.

Innovation Solution

A method involving oxidation treatment to convert the outermost layer of the first group III nitride into a protective layer of group III oxide, followed by removing this layer in a reducing atmosphere within the processing chamber before regrowing the second group III nitride, thereby reducing impurity concentration at the interface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the substrate is unloaded from the depositing apparatus after growing the first group III nitride, then the substrate can be processed externally, but impurities adhere to the surface during unloading and storage

Engineering Contradiction:

Improvesubstrate processing flexibilityVSAvoidimpurity adhesion

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

A protective layer composed of silicon oxide is introduced as an intermediary substance between the first group III nitride surface and the external environment. This protective layer prevents impurity adhesion during unloading and storage, while allowing flexible external processing of the substrate.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If the protective layer is removed by unloading the substrate and performing external treatment, then the treatment can be performed with specialized equipment, but the substrate must be unloaded which exposes it to impurity contamination

Engineering Contradiction:

Improveprotective layer removal capabilityVSAvoidimpurity contamination

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The protective layer formation and removal processes are merged into a single continuous operation within the depositing apparatus. The protective layer is formed by in-situ oxidation and subsequently removed by in-situ heating in a reducing atmosphere, eliminating the need to unload the substrate and preventing impurity contamination throughout the process.

Inventive Principle:

Principle #5Merging (Combining)

3Productivity

If impurities are present on the surface of the first group III nitride, then the regrowth process can proceed without additional cleaning steps, but the electrical conductivity and crystallinity of the regrown layer are degraded

Engineering Contradiction:

Improveregrowth process speedVSAvoidinterface quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The protective layer is formed in advance before the regrowth process, creating a barrier that prevents impurity adhesion during substrate handling. This preliminary protective action ensures that when regrowth occurs, the interface quality is maintained at high standards without requiring additional cleaning steps, thus preserving both productivity and manufacturing precision.

Inventive Principle:

Principle #10Preliminary action

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 method effectively reduces impurity concentrations, improving crystallinity and electrical conductivity at the interface, eliminating the need for thick regrowth and minimizing device performance degradation.

Implementation Method 1

subjecting the substrate to a predetermined oxidation treatment using an oxidation treatment device to convert an outermost layer of the first group III nitride into a protective layer composed of a group III oxide

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 2

heating the substrate in a reducing atmosphere to remove the protective layer from a surface of the substrate

Methodology Applied

Scientific EffectReduction: Reduction

Data Source

PatentUS20250236988A1Method for manufacturing nitride stack and nitride stack

Publication Date: 2025.07.24 SUMITOMO CHEM CO LTD

AI summary

There is provided a method for manufacturing a nitride stack, including: (a) preparing a substrate having at least a surface layer portion composed of a first group III nitride, the substrate being unloaded from a depositing apparatus in which the first group III nitride has been grown; (b) subjecting the substrate to a predetermined oxidation treatment using an oxidation treatment device to convert an outermost layer of the first group III nitride into a protective layer composed of a group III oxide; (c) loading the substrate into a predetermined processing chamber and heating the substrate in a reducing atmosphere to remove the protective layer from a surface of the substrate; and (d) growing a second group III nitride on a surface of the first group III nitride exposed by removing the protective layer, without unloading the substrate from the processing chamber.