Capacitively Coupled Field Plates for High-Voltage GaN HEMTs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Breakdown voltage of high electron mobility transistors (HEMTs) and gallium nitride (GaN) HEMTs is limited by non-uniform electric fields in the drift region, and traditional field plate designs increase process cost and complexity to achieve uniform field distribution.
Innovation Solution
Capacitance networks with fixed numbers of capacitively coupled field plates are integrated or external, allowing for controlled distribution of electric fields by pre-determining field plate potentials, thereby achieving a substantially uniform electric field distribution along the drift region without increasing process cost or complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional field plate designs are used to achieve uniform electric field distribution, then breakdown voltage is improved, but process cost and complexity increase
Solution Approach 1:
The patent changes the electrical parameters of the field plates by introducing a capacitance network that applies different potentials to multiple field plates. This parameter change transforms the uniform potential field into a controlled non-uniform potential distribution, which in turn creates a uniform electric field in the drift region, resolving the contradiction between achieving uniform field distribution and maintaining process simplicity
Solution Approach 2:
The capacitance network serves as an intermediary element between the power supply and the field plates. It mediates the potential distribution across the field plates, enabling precise control of the electric field without requiring complex processing steps. This intermediary structure allows the system to achieve uniform electric field distribution while avoiding the need for complex traditional field plate designs
2Reliability
If traditional field plate designs are used to achieve uniform electric field distribution, then breakdown voltage is improved, but manufacturing cost increases
Solution Approach 1:
The field plates are designed to serve multiple functions: they act as both the primary field management structure and as nodes for the capacitance network. This multi-functionality allows the same structural elements to achieve both the uniform electric field distribution and the potential control, eliminating the need for additional complex manufacturing steps and reducing overall manufacturing cost
Solution Approach 2:
By changing the electrical parameters (potentials) of existing field plates through the capacitance network rather than changing their physical structure, the patent achieves uniform electric field distribution without requiring additional processing steps. This parameter-based approach is more cost-effective than structural modifications
3Device complexity
If non-uniform electric fields are present in the drift region, then device structure is simpler, but breakdown voltage is limited
Solution Approach 1:
The capacitance network acts as an intermediary that transforms the simple non-uniform field structure into a controlled uniform field distribution. It mediates between the simple device structure and the requirement for high breakdown voltage by introducing minimal additional components that enable precise electric field control
Solution Approach 2:
The patent changes the electrical parameters of the field plates through the capacitance network to create a uniform electric field in the drift region. This parameter change enables high breakdown voltage while maintaining the simplicity of the basic device structure, as no major structural modifications are required
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 capacitance networks enable high voltage operation of HEMTs with a uniform electric field, reducing dynamic on-resistance and supporting higher breakdown voltages while maintaining cost-effectiveness.
Implementation Method 1
capacitance networks with fixed numbers of capacitively coupled field plates are integrated or external, allowing for controlled distribution of electric fields by pre-determining field plate potentials
Implementation Method 2
achieving a substantially uniform electric field distribution along the drift region
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
Capacitance networks for enhancing high voltage operation of high electron mobility transistors (HEMTs) are presented herein. A capacitance network, integrated and/or external, may be provided with a fixed number of capacitively coupled field plates to distribute the electric field in the drift region. The capacitively coupled field plates may advantageously be fabricated on the same metal layer to lower cost; and the capacitance network may be provided to control field plate potentials. The potentials on each field plate may be pre-determined through the capacitance network, resulting in a uniform, and/or a substantially uniform electric field distribution along the drift region.