Lateral GaN Rectifier Structure for HEMT Compatibility and Breakdown
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power semiconductor devices, particularly silicon-based ones, face limitations in handling high currents and reverse bias voltages, while GaN-based devices struggle to maintain performance compatibility with HEMT structures without significant performance loss, especially in achieving low on-resistance and high reverse breakdown voltage.
Innovation Solution
A high-electron mobility transistor (HEMT)-compatible lateral field-effect rectifier device is developed, featuring a layer of doped III-N semiconductor material and a gate isolation layer to modulate threshold voltage and reduce leakage, with a passivation layer to enhance device reliability and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If GaN-based power devices are developed to handle larger currents and support larger reverse bias voltages, then the power handling capability is improved, but the compatibility with HEMT structures is compromised
Solution Approach 1:
The device is divided into distinct functional regions: a drift region for voltage blocking, a barrier layer for carrier confinement, and a contact region for current extraction. This segmentation allows each region to be optimized independently for its specific function while maintaining overall HEMT structure compatibility.
Solution Approach 2:
Different regions of the device are assigned different material compositions and doping profiles tailored to local requirements. The drift region uses lower Al composition for lower breakdown field, while the barrier layer uses higher Al composition for better carrier confinement, achieving local optimization without compromising overall structure compatibility.
2Stress or pressure
If the reverse breakdown voltage is increased in GaN rectifiers, then the voltage handling capability is improved, but the on-resistance increases
Solution Approach 1:
The device utilizes changes in Al composition parameter across different layers to simultaneously achieve high breakdown voltage and low on-resistance. The gradual transition in Al composition allows optimization of both parameters by controlling the electric field distribution and carrier mobility in different regions.
Solution Approach 2:
The rectifier employs a composite structure with multiple AlGaN layers having different Al compositions and doping levels. This composite material approach enables the device to achieve both high voltage blocking capability through the drift region and low on-resistance through the barrier and contact regions.
3Adaptability or versatility
If a lateral rectifier structure is implemented in GaN, then the integration with HEMT is improved, but the reverse breakdown voltage performance deteriorates
Solution Approach 1:
The invention transitions from a vertical rectifier structure to a lateral structure, changing the current flow dimension. This allows the rectifier to be integrated alongside HEMTs in the same epitaxial layer, achieving planar integration while maintaining high breakdown voltage through optimized lateral drift region design.
Solution Approach 2:
The barrier layer acts as an intermediary between the drift region and the contact region, mediating the transition of carriers and electric field. This intermediary structure enables the lateral configuration to achieve high breakdown voltage by controlling carrier behavior at the interface regions.
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 solution achieves a high reverse breakdown voltage and low gate leakage, comparable to state-of-the-art GaN rectifiers, with improved on-resistance and power figure of merit, while maintaining compatibility with HEMT structures.
Implementation Method 1
A layer of doped III-N semiconductor material is disposed over the electron supply layer... The layer of doped III-N semiconductor material modulates the threshold voltage of the rectifier device
Implementation Method 2
A passivation layer is disposed over the electron supply layer and the layer of doped III-N semiconductor material... achieves a high reverse breakdown voltage and low gate leakage
Data Source
AI summary
The present disclosure, in some embodiments, relates to a semiconductor device. The semiconductor device includes an electron supply layer that is disposed over an upper surface of a semiconductor material and that is laterally arranged between a first conductive terminal and a second conductive terminal. A III-N (III-nitride) semiconductor material is disposed over the electron supply layer. A passivation layer is disposed over the III-N semiconductor material, along a side of the III-N semiconductor material, and over the electron supply layer. An insulating material is arranged over the passivation layer and along opposing sidewalls of the second conductive terminal, and a gate structure is disposed over the passivation layer. The passivation layer has an uppermost surface that is directly coupled to a sidewall of the passivation layer. The insulating material extends along the sidewall of the passivation layer.