β-Ga2O3 Crystal Laminate Doping via HVPE Epitaxial Growth
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Solution Overview
Problem
Current methods for doping β-Ga2O3-based single crystals, such as MBE, EFG, and ion implantation, face challenges including impurity segregation, limited doping concentration range, and crystallinity deterioration due to ion beam damage.
Innovation Solution
A method using the HVPE technique to grow β-Ga2O3-based single crystal films with a broad dopant concentration range, incorporating a dopant during crystal growth and maintaining high crystallinity by controlling the GaCl and O2 partial pressures, allowing for uniform dopant distribution and preventing carrier compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If MBE method is used to dope β-Ga2O3-based single crystal, then doping concentration can be controlled, but doping concentration cannot reach not less than 1×10^18 atoms/cm³ due to carrier compensation
Solution Approach 1:
The patent changes the doping method from MBE to ion implantation followed by thermal annealing, which allows achieving doping concentrations of not less than 1×10^18 atoms/cm³ without carrier compensation. The thermal annealing process activates the dopants effectively, enabling high doping concentrations while maintaining electrical properties.
2Quantity of substance
If EFG method is used to grow β-Ga2O3-based single crystal, then high purity crystal can be obtained, but dopant concentration cannot exceed about 1×10^17 atoms/cm³ due to raw material impurity limits
Solution Approach 1:
The patent performs ion implantation before thermal annealing, allowing precise control of dopant concentration independent of raw material purity. The dopant is introduced in a controlled manner through ion implantation, enabling concentrations exceeding 1×10^17 atoms/cm³ while maintaining crystal quality through subsequent thermal annealing that repairs any damage and activates dopants.
Solution Approach 2:
The patent replaces the mechanical mixing of dopants during crystal growth (EFG method) with ion implantation, which allows precise control of dopant concentration and distribution. This substitution enables achieving higher doping concentrations without being limited by raw material impurity levels.
3Quantity of substance
If ion implantation is used to dope crystal, then dopant can be introduced, but implantation depth is limited to about 1 μm and crystallinity deteriorates due to ion beam damage
Solution Approach 1:
The patent performs ion implantation to introduce dopants, followed by thermal annealing to repair ion beam damage and activate dopants. The thermal annealing process restores crystallinity while maintaining the introduced dopant concentration, overcoming the limitation of ion beam damage.
Solution Approach 2:
The patent uses thermal annealing to recover and repair the crystal structure damaged by ion implantation. The annealing process eliminates vacancies and voids created by ion beam, restoring crystallinity while preserving the dopant introduction achieved through ion implantation.
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
Enables the formation of β-Ga2O3-based single crystal films with a wide range of dopant concentrations, ensuring high crystallinity and uniformity, surpassing limitations of other methods by avoiding impurity segregation and ion beam damage.
Implementation Method 1
A method using the HVPE technique to grow β-Ga2O3-based single crystal films
Implementation Method 2
grow β-Ga2O3-based single crystal films with a broad dopant concentration range, incorporating a dopant during crystal growth
Implementation Method 3
maintaining high crystallinity by controlling the GaCl and O2 partial pressures
Data Source
AI summary
[Problem] To provide a crystal laminate structure having a β-Ga2O3 based single crystal film in which a dopant is included throughout the crystal and the concentration of the dopant can be set across a broad range. [Solution] In one embodiment of the present invention, provided is a crystal laminate structure 1 which includes: a Ga2O3 based substrate 10; and a β-Ga2O3 based single crystal film 12 formed by epitaxial crystal growth on a primary face 11 of the Ga2O3 based substrate 10 and including Cl and a dopant doped in parallel with the crystal growth at a concentration of 1 × 1013 to 5.0 × 1020 atoms/cm3.