Corundum Oxide Semiconductor Laminate With Low-Silicon Resistivity Control

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Solution Overview

Problem

Existing semiconductor devices using gallium oxide suffer from insufficient electric resistivity, hindering the development of high-performance semiconductor devices.

Innovation Solution

A film forming method and apparatus that utilize a non-silicone resin conveyor to control silicon concentration in the semiconductor film, forming a laminate with a corundum structure and dopants like tin or germanium, achieving a resistivity of 150 mΩ·cm or less, and a carrier mobility of 20 cm²/Vs or more.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional mist CVD method is used to form gallium oxide thin film, then the film can be grown with corundum structure, but the electric resistivity is insufficient (above 200 mΩ·cm)

Engineering Contradiction:
Improveelectric resistivityVSAvoiddoping control difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention changes the silicon concentration parameter to achieve the desired electrical properties. By precisely controlling the silicon concentration to be 5.0×10^20 atoms/cm³ or less, the patent achieves electric resistivity of 200 mΩ·cm or more while maintaining the corundum structure. This parameter change is accomplished through modified doping processes and precursor composition control.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies local quality by creating specific doping regions with controlled silicon concentrations. The patent forms regions with different silicon concentrations to achieve both high resistivity in certain areas and proper electrical conductivity in others, enabling complex device structures with tailored electrical properties.

Inventive Principle:
Principle #3Local quality

2Reliability

If higher dopant concentration is introduced to reduce resistivity, then electric conductivity improves, but carrier mobility decreases

Engineering Contradiction:
Improveelectric conductivityVSAvoidcarrier mobility
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The invention optimizes the balance between dopant concentration and carrier mobility by precisely controlling silicon concentration at 5.0×10^20 atoms/cm³ or less. This specific parameter control enables achieving electric resistivity of 200 mΩ·cm or more while maintaining carrier mobility of 20 cm²/Vs or more, resolving the trade-off between conductivity and mobility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses composite doping strategies combining silicon with other dopants (Ge, Sn, Ti, Zr, Hf) to achieve both high conductivity and maintained mobility. The composite approach allows synergistic effects where different dopants contribute differently to electrical properties, enabling optimization of both parameters simultaneously.

Inventive Principle:
Principle #40Composite materials

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 and apparatus enable the production of high-quality semiconductor films with low resistivity and improved electrical properties, suitable for high breakdown voltage, low loss, and high heat resistance semiconductor devices.

Implementation Method 1

a gallium compound such as gallium acetylacetonate is dissolved in an acid such as hydrochloric acid to prepare a precursor. This precursor is atomized to generate raw-material fine particles.

Methodology Applied
Scientific EffectAtomization:

Implementation Method 2

A gas mixture in which the raw-material fine particles are mixed with a carrier gas is supplied to a surface of a substrate

Methodology Applied
Scientific EffectGas flow convection: Convection

Implementation Method 3

The raw-material mist is allowed to react, so that a single-orientation gallium oxide thin film is epitaxially grown on the substrate.

Methodology Applied
Scientific EffectChemical Vapor Deposition: Chemical Vapour Deposition

Implementation Method 4

a single-orientation gallium oxide thin film is epitaxially grown on the substrate

Methodology Applied
Scientific EffectEpitaxy: Epitaxy

Data Source

PatentEP3901994B1Multilayer body, film forming method and film forming apparatus
Publication Date: 2025.12.31 SHIN ETSU CHEMICAL CO LTD
  • EP3901994B1 patent drawingFigure 1~2
  • EP3901994B1 patent drawingFigure 3~4
  • EP3901994B1 patent drawingFigure 5

AI summary

The present invention is a laminate including: a crystal substrate; and a semiconductor film provided on a main surface of the crystal substrate, the semiconductor film being mainly made of an oxide semiconductor containing a dopant and having a corundum structure, where the oxide semiconductor has a silicon concentration of 5.0×1020 cm-3 or less, and the semiconductor film has a resistivity of 150 mΩ·cm or less. This provides a laminate including a semiconductor having low resistance and a corundum structure suitable for use in semiconductor devices.