Alpha-Ga2O3 Semiconductor Film Crystal Quality via Buffer Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
α-Ga2O3 semiconductor films used in power semiconductors face challenges due to their metastable phase, leading to high crystal defects, warpage, and mosaic crystal formation, which degrade dielectric breakdown field characteristics.
Innovation Solution
The α-Ga2O3 based semiconductor film is developed with a corundum-type crystal structure, where the X-ray rocking curve full width at half maximum of the (104) plane is set to 500 arcsec or less, significantly reducing crystal defects and warpage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single-crystal substrate is used for α-Ga2O3, then crystal quality is improved, but manufacturing difficulty increases due to the metastable phase requiring heteroepitaxial growth on sapphire substrates
Solution Approach 1:
The patent introduces a buffer layer composed of α-Ga2O3 and α-Al2O3 as an intermediary between the sapphire substrate and the α-Ga2O3 semiconductor layer. This buffer layer serves as a mediator that reduces lattice mismatch and minimizes crystal defects, enabling high-quality single-crystal growth on heteroepitaxial substrates without requiring difficult-to-obtain single-crystal sapphire substrates.
2Ease of manufacture
If heteroepitaxial growth on sapphire substrate is used, then ease of manufacture is improved, but crystal defects increase due to lattice constant difference
Solution Approach 1:
The buffer layer acts as an intermediary that gradually transitions the lattice structure from sapphire to α-Ga2O3, reducing the abrupt lattice mismatch and minimizing dislocation formation. This mediator layer enables the use of readily available sapphire substrates while maintaining high crystal quality.
Solution Approach 2:
The patent changes the compositional parameter of the buffer layer by controlling the ratio of α-Ga2O3 to α-Al2O3, creating a gradient structure that optimizes lattice matching. This parameter adjustment allows for progressive lattice constant transition, reducing crystal defects while maintaining ease of manufacture.
3Reliability
If α-Ga2O3 film is used for high withstand voltage applications, then dielectric breakdown field characteristics are improved, but crystal defects degrade these characteristics
Solution Approach 1:
The buffer layer serves as a protective intermediary that filters out crystal defects before they reach the active α-Ga2O3 semiconductor layer. By capturing and containing defects in the buffer layer, the patent protects the high-performance semiconductor layer from defect-induced degradation of dielectric breakdown characteristics.
4Ease of operation
If semiconductor film has large warpage, then ease of handling is worsened due to cracks, but manufacturing precision is affected by film thickness distribution
Solution Approach 1:
The buffer layer acts as a stress-mediated intermediary that compensates for thermal expansion and lattice mismatch differences between sapphire and α-Ga2O3. This mediator reduces warpage forces, enabling the semiconductor film to be handled easily without cracking while maintaining uniform film thickness and manufacturing precision.
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 results in semiconductor films with remarkably few crystal defects, minimal warpage, and reduced mosaicity, leading to improved dielectric breakdown electric field characteristics and high-quality functional layers.
Implementation Method 1
α-Ga2O3, which is a semi-stable phase, has a very large band gap of 5.3 eV
Implementation Method 2
an X-ray rocking curve full width at half maximum of a (104) plane on at least one surface of the semiconductor film
Data Source
AI summary
Provided is a semiconductor film having a corundum-type crystal structure composed of α-Ga2O3 or an α-Ga2O3 solid solution, and an X-ray rocking curve full width at half maximum of a (104) plane on at least one surface of the semiconductor film is 500 arcsec or less.