Wide-Bandgap Guard Ring Structure for Edge Electric Field Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor devices face challenges in effectively relaxing electric field crowding in the edge-termination area, which can lead to device destruction at low voltages without adequate edge-termination structures.
Innovation Solution
A semiconductor device with a wide bandgap semiconductor layer, featuring a plurality of guard rings of a second conductivity type and separation regions with co-doped impurities in a concentric ring shape to effectively relax electric field crowding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional photolithography and ion implantation processes are used to form guard rings, then the edge-termination structure can be provided to mitigate electric field crowding, but the manufacturing time and cost increase due to requiring photomask fabrication, ion implantation, and mesa-groove forming processes
Solution Approach 1:
The patent combines the formation of the guard ring and the mesa groove into a single ion implantation process. The guard ring is formed by implanting first conductivity type impurities, while the mesa groove is simultaneously formed by implanting second conductivity type impurities at a different location, eliminating the need for separate photomask fabrication and processing steps for each structure.
Solution Approach 2:
A single ion implantation process performs multiple functions: it forms both the guard ring structure for electric field mitigation and the mesa groove structure for device isolation. This multi-functional approach reduces the total number of manufacturing steps while achieving both structural requirements.
2Reliability
If conventional photolithography and ion implantation processes are used to form guard rings, then the edge-termination structure can be provided to mitigate electric field crowding, but the manufacturing cost increases due to multiple required processes
Solution Approach 1:
The patent merges the guard ring formation and mesa groove formation into one ion implantation step, reducing the total number of manufacturing processes. This consolidation eliminates the need for separate photomask fabrication, multiple implantation steps, and associated processing, thereby reducing manufacturing cost while maintaining the reliability benefits of the edge-termination structure.
3Reliability
If guard rings are formed using conventional processes, then the edge-termination structure is provided, but the device complexity increases due to multiple processing steps including photomask fabrication, ion implantation, and mesa-groove forming
Solution Approach 1:
The patent combines multiple device structures (guard ring and mesa groove) into a single ion implantation process, reducing process complexity. By using different implantation locations and conductivity types within one process step, the patent simplifies the manufacturing workflow while still providing the necessary edge-termination functionality for reliable electric field mitigation.
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 proposed solution enhances the manufacturing efficiency and reduces costs by simplifying the process of forming guard rings without the need for mesa-groove forming, while effectively mitigating electric field crowding and improving the reliability of the semiconductor device.
Implementation Method 1
the separation region contains both first impurities of the first conductivity type and second impurities of the second conductivity type
Data Source
AI summary
A semiconductor device has an active area in which a main current flows and an outer-edge area surrounding the active area. The semiconductor device includes: an n-type semiconductor layer made of a wide bandgap semiconductor; a plurality of p-type guard rings provided inside the semiconductor layer in the outer-edge area to surround the active area; and a separation region provided in a concentric ring shape in the outer-edge area to be in contact with both of the adjacent guard rings, wherein the separation region contains both n-type first impurities and p-type second impurities.