Embedded III-V HEMT Structure for Higher Breakdown Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high electron mobility transistors (HEMTs) face challenges in increasing breakdown voltage and reducing on-state resistance without increasing total thickness, which is necessary for higher integration of semiconductor components.
Innovation Solution
A high electron mobility transistor structure is designed with a first III-V compound layer on a substrate, a second III-V compound layer embedded within the first, and a P-type gallium nitride gate embedded in the second layer, along with specific etching and epitaxial processes to form electrodes and trenches, maintaining a trench profile for two-dimensional electron gas generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the total thickness of the HEMT is increased to improve breakdown voltage and reduce on-state resistance, then the performance is improved, but the integration density deteriorates
Solution Approach 1:
The patent embeds a second III-V compound layer within a first III-V compound layer, creating a nested structure where the gate electrode is positioned within the embedded layer. This nesting approach allows the gate to be surrounded by multiple layers of different compositions, effectively increasing the vertical thickness for electrical performance without increasing the overall device footprint, thereby maintaining integration density while improving breakdown voltage and reducing on-state resistance.
Solution Approach 2:
The patent employs different III-V compound layers with different compositions (e.g., AlGaN with different Al content) at different vertical positions within the device. The embedded layer has a different composition than the outer layer, creating local variations in material properties that optimize the electrical characteristics at specific regions, allowing high breakdown voltage and low on-state resistance without requiring uniform thickness increase throughout the entire device.
2Reliability
If the total thickness of the HEMT is increased to reduce on-state resistance, then the performance is improved, but the integration density deteriorates
Solution Approach 1:
The embedded second III-V compound layer within the first layer creates a nested configuration that increases the effective vertical thickness for current flow paths, reducing on-state resistance. The gate electrode positioned within the embedded layer allows for optimized field distribution that reduces resistance without requiring a proportional increase in overall device thickness, thus maintaining integration density.
Solution Approach 2:
The patent uses composite structures with multiple III-V compound layers of different compositions (e.g., AlGaN layers with varying aluminum content) to create optimized electrical pathways. The different material compositions provide tailored electrical properties at different depths, reducing on-state resistance through improved carrier transport without requiring uniform thickness increase, thereby preserving integration density.
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 structure achieves higher breakdown voltage and lower on-state resistance without increasing overall thickness, enabling improved performance in high power and high frequency applications.
Implementation Method 1
A two-dimensional electron gas (2DEG) may be generated by the piezoelectric property of the GaN-based materials
Data Source
AI summary
A high electron mobility transistor includes a substrate. A first III-V compound layer is disposed on the substrate. A second III-V compound layer is embedded within the first III-V compound layer. A P-type gallium nitride gate is embedded within the second Ill-V compound layer. A gate electrode is disposed on the second III-V compound layer and contacts the P-type gallium nitride gate. A source electrode is disposed at one side of the gate electrode. A drain electrode is disposed at another side of the gate electrode.