GaN Substrate Carbon Removal via Oxidation

Solution Overview

Problem

The existing methods for polishing gallium nitride substrates, which use diamond as a loose abrasive and wax for fixing, result in residual carbon on the substrate surface, leading to poor crystal quality and decreased emission intensity in optical devices.

Innovation Solution

A gallium nitride substrate is developed with a GaLα/CKα peak intensity ratio of not less than 2, as measured by energy dispersive X-ray microanalysis, to minimize residual carbon on the surface, thereby enhancing the crystal quality of the epitaxial growth layer and improving emission intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If diamond is used as loose abrasive for polishing GaN substrate, then polishing effect is achieved, but residual carbon remains on substrate surface

Engineering Contradiction:

Improvesubstrate surface qualityVSAvoidresidual carbon on substrate surface

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes the harmful carbon components from the substrate surface through specific cleaning treatments. The cleaning process selectively removes residual carbon from diamond abrasive and wax without damaging the GaN substrate, thereby eliminating the harmful factor while preserving the polishing quality.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs strong oxidizing agents such as ozone or peroxide in the cleaning treatment to accelerate the oxidation and removal of residual carbon on the substrate surface. This chemical oxidation process effectively eliminates carbon contaminants that mechanical cleaning cannot remove, solving the contradiction between achieving polish and avoiding carbon residue.

Inventive Principle:

Principle #38Strong oxidants (Accelerated oxidation)

2Ease of manufacture

If wax is used for fixing GaN substrate during polishing, then substrate is secured, but carbon component from wax remains on surface

Engineering Contradiction:

Improvesubstrate fixing during polishingVSAvoidcarbon component from wax

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes the harmful carbon components from the substrate surface through specific cleaning treatments. The cleaning process selectively removes residual carbon from diamond abrasive and wax without damaging the GaN substrate, thereby eliminating the harmful factor while preserving the polishing quality.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs strong oxidizing agents such as ozone or peroxide in the cleaning treatment to accelerate the oxidation and removal of residual carbon on the substrate surface. This chemical oxidation process effectively eliminates carbon contaminants that mechanical cleaning cannot remove, solving the contradiction between achieving polish and avoiding carbon residue.

Inventive Principle:

Principle #38Strong oxidants (Accelerated oxidation)

3Manufacturing precision

If GaN substrate is polished using conventional methods, then surface flatness is improved, but crystal quality of epitaxial growth layer deteriorates

Engineering Contradiction:

Improvesurface flatnessVSAvoidcrystal quality of epitaxial growth layer

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent extracts and removes the harmful carbon components from the substrate surface through specific cleaning treatments. The cleaning process selectively removes residual carbon from diamond abrasive and wax without damaging the GaN substrate, thereby eliminating the harmful factor while preserving the polishing quality.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs strong oxidizing agents such as ozone or peroxide in the cleaning treatment to accelerate the oxidation and removal of residual carbon on the substrate surface. This chemical oxidation process effectively eliminates carbon contaminants that mechanical cleaning cannot remove, solving the contradiction between achieving polish and avoiding carbon residue.

Inventive Principle:

Principle #38Strong oxidants (Accelerated oxidation)

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 reduced residual carbon on the substrate surface results in improved crystal quality and increased emission intensity of optical devices, reducing failures and enhancing yield.

Implementation Method 1

energy dispersive X-ray microanalysis (EDX) of a surface of the gallium nitride substrate using a scanning electron microscope (SEM)

Methodology Applied

Scientific EffectX-ray generation: X-Ray

Data Source

PatentUS10381230B2Gallium nitride substrate and optical device using the same

Publication Date: 2019.08.13 SUMITOMO CHEM CO LTD

AI summary

A method of processing a gallium nitride substrate, includes providing a gallium nitride substrate, polishing a surface of the gallium nitride substrate, and cleaning the polished surface of the gallium nitride substrate. The polished surface includes a GaLα/CKα peak intensity ratio in energy dispersive X-ray microanalysis (EDX) spectrum which is not less than 2, the EDX spectrum being obtained in an EDX of the surface of the gallium nitride substrate using a scanning electron microscope (SEM) at an accelerating voltage of 3 kV.