MOSFET Edge Termination Layout With Shield Oxide Trenches
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Solution Overview
Problem
Existing edge termination structures for MOSFET transistors in power applications lack high area efficiency, limiting the active area and current capacity, and require multiple masks in the manufacturing process, increasing costs.
Innovation Solution
An edge termination structure for MOSFET transistors featuring parallel strips connected by shield oxide-filled trenches (SOTR) perpendicular to the strips, optionally with dummy trenches, optimizing the design to enhance area efficiency and reduce manufacturing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If conventional edge termination structures are used, then the device provides adequate edge termination, but the area efficiency is low and active area is limited
Solution Approach 1:
The invention transitions from conventional planar edge termination to a three-dimensional structure by forming recesses in the semiconductor substrate. These recesses create vertical dimensionality with shield structures extending into the substrate, allowing more efficient space utilization and increased active area without proportionally increasing overall device footprint.
Solution Approach 2:
The edge termination structure is segmented into multiple discrete components: mesas (conductive regions), trenches (isolating structures), and shield structures (protective layers). This segmentation allows each component to be optimized independently and arranged to maximize area efficiency while maintaining electrical isolation and termination functions.
2Ease of manufacture
If conventional termination processes are used, then adequate edge termination is achieved, but multiple masks are required increasing manufacturing cost
Solution Approach 1:
The invention merges the formation of trenches and shield structures into a single etching process step. By designing the shield structure to extend into the trench and share common etching parameters, the process consolidates multiple alignment-critical steps into one, reducing mask requirements and manufacturing complexity while maintaining precise geometric control through unified process parameters.
Data Source
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AI summary
The present disclosure relates to an edge termination structure suitable for the MOSFET transistor especially in power applications. An edge termination structure, suitable for the MOSFET transistor, comprising a plurality of parallel strips (1) and at least one a shield oxide filled trench, SOTR, (6) wherein the SOTR (6) is perpendicular to the strips (1) and connects with the stripes (1) at the end portion (12) of the stripes (1).