Backside Field-Plated GaN HEMT Soft Switching for Lower Power Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gallium nitride (GaN) based semiconductor devices face high power loss and stress during hard-switching events due to simultaneous non-zero current and voltage, which can harm the device and reduce reliability.
Innovation Solution
A backside field-plated GaN HEMT device is used as a four-terminal device, where the backside field plate (BFP) is independently biased to adjust the 2DEG current density, enabling soft-switching by reducing channel current during switching events, thus minimizing power loss and stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If hard-switching is used in GaN devices, then switching speed is fast, but power loss and stress increase during switching events
Solution Approach 1:
The backside field plate is biased to reduce the 2DEG current density before the switching event occurs. By preliminarily reducing the channel current through independent BFP control, the overlap between current and voltage during switching is minimized, thereby reducing power loss while maintaining fast switching speed.
2Device complexity
If hard-switching is used in GaN devices, then device simplicity is maintained, but stress on the device increases during switching
Solution Approach 1:
The backside field plate acts as an intermediary element that independently controls the 2DEG channel density. By introducing this additional control terminal, the device can reduce channel current before switching events, thereby reducing stress and power loss during switching while maintaining the overall device structure.
3Loss of energy
If backside field plate is independently biased to reduce channel current, then power loss during switching is reduced, but device complexity increases
Solution Approach 1:
The device is segmented into additional control terminals, specifically the backside field plate that can be independently biased. This segmentation allows separate control of the 2DEG channel density, enabling power loss reduction during switching by reducing channel current before switching events, despite the increased number of control terminals.
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 independent control of the backside field plate reduces power loss and stress on the device during switching, enabling efficient operation and improving reliability by allowing minimal overlap of current and voltage, characteristic of soft-switching.
Implementation Method 1
a backside field plate disposed at least partially within the substrate, the backside field plate configured to modulate an electric field between the gate electrode and the drain electrode of the transistor device
Implementation Method 2
The backside field plate (BFP) may be independently biased and used to adjust the 2DEG current density in the device
Data Source
AI summary
This disclosure describes various techniques to use a backside field-plated GaN HEMT device as a four-terminal device. The backside field plate (BFP) may be independently biased and used to adjust the 2DEG current density in the device. By independently controlling the 2DEG channel density using the BFP, the channel current may be reduced prior to switching events, thereby enabling soft-switching using the BFP. Thus, the BFP may be used to reduce the current through the device during switching events to reduce the power loss and stress on the device that may occur during hard-switching.