Beta-Ga2O3 Substrate Orientation for HVPE Growth

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Solution Overview

Problem

Existing methods for growing β-Ga2O3-based single crystal films by the HVPE method face challenges in achieving high growth rates and good surface morphology on semiconductor substrates.

Innovation Solution

The method involves adjusting the angle θ between the principal plane of the β-Ga2O3-based single crystal substrate and the (100) plane to specific ranges, such as not less than 0.3° and not more than 15° for high growth rates, and not less than 41.6° and not more than 78.4° for improved surface morphology.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the principal plane of the substrate is adjusted to a predetermined plane orientation for high growth rate, then the growth rate increases, but the surface morphology deteriorates

Engineering Contradiction:
Improvegrowth rateVSAvoidsurface morphology
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention changes the plane orientation parameter of the substrate from conventional orientations to a specific range (50-90 degrees rotated from the (100) face), which simultaneously optimizes both growth rate and surface morphology. This parameter adjustment resolves the contradiction by finding an optimal orientation that balances both requirements.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the growth temperature is increased to 900°C or higher for high quality crystal growth, then the crystal quality improves, but the process complexity increases

Engineering Contradiction:
Improvecrystal qualityVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention raises the growth temperature to 900°C or higher, which thermodynamically favors high-quality crystal formation with fewer defects. Although this requires more sophisticated temperature control, the benefit of obtaining high-quality β-Ga2O3 single crystal films justifies the increased process complexity.

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

This approach allows for the efficient growth of β-Ga2O3-based single crystal films with high growth rates and enhanced surface morphology, improving the quality and yield of semiconductor elements.

Implementation Method 1

a technique of forming a β-Ga2O3 single crystal film on a β-Ga2O3-based substrate by epitaxial crystal growth using the MBE (Molecular Beam Epitaxy) method

Methodology Applied
Scientific EffectEpitaxial crystal growth: Epitaxy

Implementation Method 2

a method for growing a β-Ga2O3-based single crystal film by using the HVPE method, and including a step for exposing a Ga2O3-based substrate to a gallium chloride gas and an oxygen-containing gas

Methodology Applied
Scientific EffectHVPE (Halide Vapor Phase Epitaxy): Chemical Vapour Deposition

Data Source

PatentEP3396030B1Semiconductor substrate, and epitaxial wafer and method for producing same
Publication Date: 2025.06.11 TAMURA KK
  • EP3396030B1 patent drawingFigure 1
  • EP3396030B1 patent drawingFigure 2
  • EP3396030B1 patent drawingFigure 3A~3D

AI summary

[Problem] To provide: a semiconductor substrate comprising a β-Ga2O3-based single crystal, with which an epitaxial layer comprising the β-Ga2O3-based single crystal can be grown by the HVPE method at a high growth rate, or with which an epitaxial layer comprising the β-Ga2O3-based single crystal having good surface morphology can be grown; an epitaxial wafer having the semiconductor substrate and an epitaxial layer; and a method for producing the epitaxial wafer. [Solution] One embodiment is a semiconductor substrate 11 which is used as an underlying substrate for epitaxial crystal growth carried out by the HVPE method, wherein the semiconductor substrate 11 comprises a β-Ga2O3-based single crystal, and a plane parallel to the [100] axis of the β-Ga2O3-based single crystal is a principal plane 12.