Super-Junction MOS with Integrated TMBS for Reverse Recovery
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Solution Overview
Problem
Common super-junction MOS devices suffer from poor reverse recovery characteristics, leading to higher peak reverse-recovery currents and potential device damage in hard switching applications, making them hazardous.
Innovation Solution
Integration of a Trench-MOS-Barrier-Schottky (TMBS) structure within the super-junction MOS device, connected in parallel with adjacent cells, which improves reverse recovery characteristics without adding extra process steps, thereby enhancing safety and simplifying manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a common super-junction MOS device structure is used, then the device achieves good balance between voltage resistance and on-resistance, but the parasitic diode exhibits poor reverse recovery characteristics leading to higher peak reverse-recovery currents and potential device damage
Solution Approach 1:
The device is divided into multiple parallel cells, with a TMBS structure integrated between adjacent cells. This segmentation allows the TMBS structure to specifically address reverse recovery issues in certain regions while maintaining the super-junction MOS device's voltage resistance and on-resistance balance in other regions.
Solution Approach 2:
The TMBS structure acts as an intermediary element integrated between adjacent cells of the super-junction MOS device. It provides a dedicated path for reverse recovery current management, mediating the harmful effects of peak reverse-recovery currents while preserving the overall device performance.
2Reliability
If an integrated TMBS structure is added to improve reverse recovery characteristics, then reverse recovery performance is enhanced, but device complexity increases
Solution Approach 1:
The TMBS structure is merged with the super-junction MOS device by integrating it between adjacent cells sharing common substrate and epitaxial layer. This combining approach enhances reverse recovery characteristics while avoiding the need for separate discrete components, thus limiting the increase in device complexity.
Solution Approach 2:
The integrated TMBS structure serves multiple functions: it improves reverse recovery characteristics, provides a path for reverse recovery current management, and maintains compatibility with the existing super-junction MOS device architecture. This multi-functionality justifies the added structural complexity by delivering multiple benefits from a single integration.
Data Source
AI summary
A super-junction MOS device with an integrated TMBS structure and a manufacturing method thereof are provided. The super-junction MOS device includes a main body. The TMBS structure is connected in parallel between at least two cells of the main body.