Strained Epitaxial Oxide Layers for High-Voltage Semiconductor Structures
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Solution Overview
Problem
Existing semiconductor devices, particularly those used in UV light emitting devices and high-power RF switches, face challenges in handling high voltages without being damaged, as they often rely on low bandgap materials with low breakdown voltages, necessitating multiple devices in series, which is inefficient.
Innovation Solution
The development of semiconductor structures incorporating epitaxial oxide materials, including superlattices, doped superlattices, graded layers, and chirp layers, which utilize wider bandgap materials like (AlxGa1-x)yOz with specific crystal symmetries to enhance breakdown voltage and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If low bandgap semiconductor materials (Si, GaAs) are used in RF switches, then ease of manufacture is improved, but breakdown voltage decreases
Solution Approach 1:
The patent changes the fundamental material parameter (bandgap) from conventional semiconductors to wide bandgap oxides, enabling single-device operation at high voltages without requiring series connections, thus improving both reliability and efficiency
Solution Approach 2:
The patent employs composite oxide semiconductor structures with different bandgaps (e.g., Al2O3/Ga2O3 heterostructures) to achieve optimal electrical properties, combining the advantages of wide bandgap materials for high voltage with controlled conductivity for efficient operation
2Reliability
If multiple transistor devices are connected in series to withstand high voltages, then breakdown voltage is improved, but device complexity increases
Solution Approach 1:
By changing the material parameter (bandgap) to wide bandgap oxides, the patent enables a single transistor device to withstand high voltages that previously required multiple devices in series, thereby reducing device complexity while maintaining high breakdown voltage capability
3Power
If Gallium-Indium-Aluminum-Nitride compositions are used for UV light emitting devices, then light emission efficiency is improved, but device complexity increases
Solution Approach 1:
The patent uses composite oxide semiconductor structures with tailored bandgaps to achieve UV light emission, simplifying the device architecture compared to complex GaInAlN compositions while maintaining high electrical conversion efficiency through optimized heterostructure design
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
These structures enable semiconductor devices to withstand higher voltages while maintaining efficiency, reducing the need for multiple devices in series and improving performance in UV light emission and high-power applications.
Implementation Method 1
a first epitaxial oxide layer on the single crystal substrate including MgO with a cubic crystal symmetry oriented in the (100) direction; and a second epitaxial oxide layer on the single crystal substrate including β-Ga2O3 oriented in the (100) direction
Data Source
AI summary
In some embodiments, a semiconductor structure includes a single crystal substrate, a first epitaxial oxide layer on the single crystal substrate, and a second epitaxial oxide layer on the single crystal substrate. The first epitaxial oxide layer can include a first oxide material with a cubic crystal symmetry. The second epitaxial oxide layer can include a second oxide material with a monoclinic crystal symmetry. The second epitaxial oxide layer can be elastically strained to the first epitaxial oxide layer. The substrate can include MgO, MgAl2O4, or β-Ga2O3. The first epitaxial oxide layer can include MgO with a cubic crystal symmetry oriented in the (100) direction, and the second epitaxial oxide layer can include β-Ga2O3 oriented in the (100) direction, where there is a 45° rotation around the (100) direction between the MgO and the β-Ga2O3 crystal structures.