GaN Transistor Field Plate Protrusions for Electric Field Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-voltage gallium nitride (GaN) transistors fall short of realizing maximum breakdown voltage due to premature breakdown caused by concentrated drain electric field lines at the edge of the gate, which existing field plate architectures are unable to effectively mitigate.
Innovation Solution
Incorporating semiconductor protrusions with non-uniform dopant concentrations or densities extending from the field plate towards the channel, allowing for enhanced control and distribution of electric field lines, thereby reducing hotspot formation and increasing the local pinch-off voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If simple transistor architecture with single gate, source and drain is used, then device complexity is reduced, but breakdown voltage is insufficient due to electric field line concentration at gate edge
Solution Approach 1:
The transistor architecture is segmented by adding multiple field plates (first field plate and second field plate) and semiconductor protrusions between the gate and drain. This segmentation divides the electric field distribution into multiple zones, preventing concentration at a single location and thereby increasing breakdown voltage while maintaining reasonable device complexity
Solution Approach 2:
Semiconductor protrusions are introduced as intermediary structures between the field plates and the channel. These protrusions mediate the electric field distribution by providing intermediate control points, allowing for more gradual field line spreading and enhanced breakdown voltage without excessive complexity
2Reliability
If field plate architecture is added to spread electric field, then breakdown voltage is improved, but device complexity increases
Solution Approach 1:
Semiconductor protrusions with non-uniform dopant concentrations are implemented to provide local quality variations. The dopant concentration varies spatially within the protrusions, allowing precise local control of electric field distribution. This enables effective field spreading with targeted complexity only where needed, rather than uniform complexity throughout the device
Solution Approach 2:
The dopant concentration parameter is varied within the semiconductor protrusions to optimize electric field distribution. By changing the dopant concentration parameter spatially, the device achieves improved breakdown voltage control without proportionally increasing overall structural complexity
3Reliability
If semiconductor protrusions with non-uniform dopant concentrations are used, then electric field distribution is enhanced, but manufacturing precision requirements increase
Solution Approach 1:
Semiconductor protrusions with predetermined dopant concentration profiles are formed before final device assembly. The non-uniform dopant distribution is established in advance during the protrusion formation process, allowing subsequent steps to focus on geometric patterning rather than complex dopant profiling, thereby managing manufacturing precision requirements
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 use of semiconductor protrusions with field plates effectively spreads the electric field, preventing premature breakdown and allowing GaN transistors to approach the material's maximum breakdown voltage potential.
Implementation Method 1
the protrusions enhance the distribution of electric field lines throughout the channel
Implementation Method 2
the protrusions comprise a non-uniform distribution of dopant concentrations or densities
Data Source
AI summary
Embodiments disclosed herein include transistor devices and methods of forming such devices. In an embodiment, a transistor device comprises a channel, where the channel comprises a first semiconductor material. In an embodiment, a source contact is at a first end of the channel, and a drain contact at a second end of the channel. In an embodiment, a gate electrode is between the source contact and the drain contact, and a field plate extends from the gate electrode towards the drain contact. In an embodiment, a plurality of protrusions extend out from the field plate towards the channel, where the protrusions comprise a second semiconductor material