Semiconductor Termination Region Connecting Trench Structure
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Solution Overview
Problem
Conventional trench Schottky diodes suffer from strong electric field crowding and inadequate breakdown voltage due to floating potential in the termination region, limiting their application in high-power or high-voltage semiconductor devices.
Innovation Solution
A connecting trench structure is introduced to electrically connect adjacent trenches, altering the electric field distribution and improving current-voltage characteristics by filling the trenches with a conductive material and forming insulating and metal layers to enhance the termination region's performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If polysilicon is filled in trenches to block reverse leakage current, then reverse leakage current is reduced, but trenches remain in floating potential state causing strong electric field crowding and inadequate breakdown voltage
Solution Approach 1:
Multiple adjacent trenches are merged into a common trench structure filled with conductive material, transforming isolated floating potential trenches into a unified electrically connected structure that disperses electric field intensity while maintaining reverse leakage current blocking capability
Solution Approach 2:
A conductive material layer is introduced as an intermediary between the semiconductor substrate and metal layer, providing electrical connection between trenches and enabling potential control to eliminate floating potential effects while the insulating layer maintains the blocking function
2Stress or pressure
If multiple trenches are formed to disperse electric field, then electric field distribution is improved, but trenches remain electrically isolated causing floating potential and strong electric field crowding
Solution Approach 1:
Electrically isolated trenches are merged into a unified conductive structure through continuous conductive material filling, maintaining the spatial distribution benefits while achieving electrical connectivity to eliminate floating potential
Solution Approach 2:
The conductive material creates an equipotential region connecting adjacent trenches, eliminating potential differences between isolated trenches and preventing electric field crowding at trench interfaces
3Object-affected harmful factors
If conventional trench structure is used to block reverse leakage, then reverse leakage current is controlled, but the structure cannot achieve high breakdown voltage for high-power applications
Solution Approach 1:
A composite structure combining insulating layers and conductive material layers is used, where the insulating layer provides reverse leakage blocking and the conductive material provides electrical connection and potential control, achieving both low leakage and high breakdown voltage
Solution Approach 2:
Different regions of the trench structure are assigned different electrical properties - the insulating layer provides high resistance for leakage blocking while the conductive material provides low resistance for electrical connection, creating locally optimized functionality
Data Source
AI summary
A termination region structure of a semiconductor device is provided, which includes: a semiconductor layer; a plurality of trenches, formed on a surface of the semiconductor layer; a connecting trench, formed on the surface of the semiconductor layer, for connecting two adjacent trenches in the plurality of trenches; a first insulating layer, formed on surfaces of the plurality of trenches, the connecting trench, and the semiconductor layer; a conductive material, formed in the plurality of trenches and the connecting trench; a second insulating layer, covering part of a surface of the first insulating layer and part of a surface of the conductive material; and a metal layer, covering part of a surface of the second insulating layer.