Crystalline Multilayer Structure for High-Voltage Semiconductor Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor devices using gallium oxide or sapphire substrates face limitations in scalability, thermal conductivity, and electrical properties, hindering the development of high-voltage, low-loss, and integrated semiconductor devices with InAlGaO-based semiconductors for power and light-emitting applications.
Innovation Solution
A crystalline multilayer structure comprising a uniaxially oriented metal layer and a crystalline oxide semiconductor layer with gallium, indium, or aluminum, allowing for improved conductivity and vertical conduction, which can be integrated with Si substrates and nitride semiconductors, enhancing thermal conductivity and reducing losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a β gallium oxide substrate is used to achieve homoepitaxial growth and high film quality, then the quality of aluminum oxide gallium thin film is improved, but the substrate size is limited and cannot be increased compared to silicon and sapphire
Solution Approach 1:
The patent introduces a buffer layer as an intermediary between the substrate and the InAlGaO-based semiconductor layer. This buffer layer mediates the lattice mismatch and thermal expansion differences, enabling high-quality film growth on larger substrates that would otherwise be incompatible with direct homoepitaxial growth
Solution Approach 2:
The patent employs a composite structure consisting of multiple layers including substrate, buffer layer, and InAlGaO-based semiconductor layer. This composite approach allows each layer to be optimized for its specific function while working together to overcome the limitations of individual materials
2Manufacturing precision
If a sapphire substrate is used to increase film quality, then the quality of corundum-structured AlXGaYO3 thin film is improved, but the quality of β-galia-structured film deteriorates and electrical conductivity is lost
Solution Approach 1:
The patent changes the compositional parameters of the semiconductor layer by using InAlGaO-based mixed crystals with variable stoichiometry (InXAlYGaZO3 where X+Y+Z=1.5 to 2.5). By adjusting the ratios of indium, aluminum, and gallium, the film can achieve both corundum structure and electrical conductivity that sapphire alone cannot provide
Solution Approach 2:
The patent applies local quality by creating regions with different compositions and structures within the semiconductor layer. The buffer layer has different properties than the active semiconductor layer, allowing each region to be optimized for its specific function while maintaining overall device performance
3Ease of manufacture
If gallium oxide or sapphire substrates are used to establish crystal growth technology, then semiconductor device fabrication is enabled, but integration with Si substrates and nitride semiconductors becomes difficult
Solution Approach 1:
The InAlGaO-based semiconductor layer serves multiple functions: it provides a crystal growth platform for nitride semiconductors, enables integration with Si substrates, and maintains the ability to fabricate high-voltage power devices. This multi-functional layer acts as a universal interface between different material systems
4Ease of manufacture
If sapphire substrate is used as base substrate, then crystal growth is enabled, but current cannot be passed to the base substrate due to insulator properties
Solution Approach 1:
The buffer layer acts as an electrical intermediary that bridges the insulating sapphire substrate and the conductive InAlGaO-based semiconductor layer. This intermediary layer enables current flow from the substrate to the active device regions while maintaining the crystal growth advantages of sapphire
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 crystalline multilayer structure achieves good electrical properties, enabling the formation of high-voltage, low-loss semiconductor devices with increased scalability and integration capabilities, while improving thermal resistance and current density.
Implementation Method 1
a crystalline multilayer structure comprising a uniaxially oriented metal layer and a crystalline oxide semiconductor layer
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
Provided is a crystalline multilayer structure having good semiconductor properties. In particular, the crystalline multilayer structure has good electrical properties as follows: the controllability of conductivity is good; and vertical conduction is possible. A crystalline multilayer structure includes a metal layer containing a uniaxially oriented metal as a major component and a semiconductor layer disposed directly on the metal layer or with another layer therebetween and containing a crystalline oxide semiconductor as a major component. The crystalline oxide semiconductor contains one or more metals selected from gallium, indium, and aluminum and is uniaxially oriented.