SiC MOSFET Source Ring Stabilization for ESD Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional silicon carbide semiconductor devices face increased displacement current and reduced electrostatic discharge (ESD) tolerance due to the reduction in edge termination region width and thickness, leading to higher electric fields and decreased current capacity in the current sensing region.
Innovation Solution
The semiconductor device incorporates a main source ring region between the edge termination region and the gate ring region, and a current sensing source ring region closer to the chip center, with a Zener diode region and short-circuit connections to stabilize source electrode potentials and enhance ESD tolerance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the edge termination region width and thickness are reduced to increase active region area, then the active region area increases, but the ESD tolerance and breakdown voltage decrease due to increased electric field
Solution Approach 1:
The device is divided into distinct functional regions: an active region for current conduction, an edge termination region for voltage sustenance, and intermediate ring regions (first ring region and second ring region) that act as transition zones. This segmentation allows each region to be optimized for its specific function without compromising the others, enabling the active region to be maximized while maintaining adequate ESD tolerance through the specialized termination and ring structures.
Solution Approach 2:
Different regions of the semiconductor device are given different structural characteristics tailored to their specific functions. The active region has optimized dimensions for current conduction, the edge termination region has specific width and thickness for voltage sustenance, and the intermediate ring regions have graduated dimensions that transition between the active and termination regions. This local optimization allows the active region area to be increased while maintaining overall device reliability through region-specific design.
2Speed
If the edge termination region width and thickness are reduced to improve switching speed, then the switching speed increases, but the breakdown voltage and ESD tolerance decrease
Solution Approach 1:
The device structure segments the functionality between the active region (for fast switching) and the edge termination region with intermediate ring regions (for voltage sustenance). This allows the active region to be designed for optimal switching performance while the termination regions maintain the necessary breakdown voltage characteristics, resolving the contradiction between switching speed and breakdown voltage.
Solution Approach 2:
The first ring region and second ring region act as intermediary structures between the active region and the edge termination region. These ring regions provide a gradual transition in dimensions and electrical characteristics, serving as a buffer that allows the active region to be optimized for speed while the edge termination region maintains breakdown voltage, thus mediating between the conflicting requirements.
3Area of moving object
If the edge termination region width is reduced to increase current sensing region area, then the current sensing region area increases, but the displacement current increases and ESD tolerance decreases
Solution Approach 1:
The device is segmented into an active region, edge termination region, and intermediate ring regions with specific functional assignments. The current sensing region can be optimized within the active region area, while the ring regions and termination region are designed to control electric field distribution, thereby limiting displacement current generation even as the sensing region area increases.
Solution Approach 2:
The intermediate ring regions are given specific dimensional and structural characteristics that create a gradual transition in electric field intensity. This local structural optimization in the ring regions allows the current sensing region area to be increased while the ring regions themselves control the electric field to minimize displacement current generation at the boundaries.
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
This configuration improves ESD tolerance and breakdown tolerance during switching by stabilizing source electrode potentials and increasing the arithmetic area of the Zener diode region, effectively mitigating current concentration at the active region ends.
Implementation Method 1
a Zener diode region and short-circuit connections to stabilize source electrode potentials and enhance ESD tolerance
Data Source
AI summary
A semiconductor device includes an active region configured by a first MOS structure region and a second MOS structure region, a gate ring region surrounding a periphery of the active region, a first ring region surrounding a periphery of the gate ring region, a second ring region surrounding a periphery of the first ring region, and a termination region surrounding a periphery of the second ring region. The semiconductor device has first first-electrodes in the first MOS structure region, second first-electrodes in the second MOS structure region, a third first-electrode in the first ring region, and a fourth first-electrode in the second ring region. The third first-electrode has a potential equal to that of the second first-electrodes, and the fourth first-electrode has a potential equal to that of the first first-electrodes.