Trench Termination Layout for Low-Resistance Shielded MOSFETs

Solution Overview

Problem

Integrating shield contact structures in semiconductor devices to reduce shield electrode resistance without adversely affecting other MOSFET characteristics, such as gate bounce and breakdown voltage, is challenging as existing structures either increase die size or degrade device performance.

Innovation Solution

A semiconductor device structure with a coupling trench and interleaved active trenches, providing shield electrode connections on opposing edges, reduces shield resistance while maintaining breakdown voltage by using an arch-termination design and gate connections without interrupting active gate trenches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If shield contact structures are integrated into MOSFET cell topography, then shield electrode resistance is reduced, but device area increases and other MOSFET characteristics are adversely affected

Engineering Contradiction:

Improveshield electrode resistanceVSAvoiddie size

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The device is divided into distinct active region and termination region, with shield contact structures placed only in the termination region. This segmentation allows the active MOSFET cells to maintain their original compact design while the termination region provides the necessary shield contact pathways, thus reducing shield electrode resistance without increasing the active device area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the device are given different structural characteristics: the active region maintains standard MOSFET cell topography for optimal switching performance, while the termination region is specifically designed with arch-termination and shield contact structures. This local differentiation allows shield resistance reduction without compromising the electrical characteristics of the active MOSFET region.

Inventive Principle:

Principle #3Local quality

2Reliability

If additional shield contact structures are added, then shield electrode resistance is reduced, but breakdown voltage performance deteriorates

Engineering Contradiction:

Improveshield electrode resistanceVSAvoidbreakdown voltage

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The device is divided into distinct active region and termination region, with shield contact structures placed only in the termination region. This segmentation allows the active MOSFET cells to maintain their original compact design while the termination region provides the necessary shield contact pathways, thus reducing shield electrode resistance without increasing the active device area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the device are given different structural characteristics: the active region maintains standard MOSFET cell topography for optimal switching performance, while the termination region is specifically designed with arch-termination and shield contact structures. This local differentiation allows shield resistance reduction without compromising the electrical characteristics of the active MOSFET region.

Inventive Principle:

Principle #3Local quality

3Reliability

If shield contact structures are integrated, then gate bounce performance improves, but device complexity increases

Engineering Contradiction:

Improvegate bounce performanceVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The shield contact structures are merged with the termination region architecture, utilizing the same trench and fill processes. The termination region's arch-termination structure serves dual purposes: providing voltage breakdown management and accommodating shield contact pathways, thereby improving gate bounce performance without adding separate complex structures.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The termination region is designed to perform multiple functions simultaneously: voltage blocking, electric field management through arch-termination, and shield contact provision. This multi-functionality reduces the need for separate dedicated shield contact structures, thereby improving gate bounce performance while limiting overall device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS20260068217A1Semiconductor device having trench termination structure and method of manufacturing

Publication Date: 2026.03.05 SEMICON COMPONENTS IND LLC

AI summary

A semiconductor device includes a first termination trench at a first edge region and a second termination trench at a second edge region. A first active trench extends from the first termination trench towards the second termination trench and terminates with a first tip region separated from the second termination trench by the termination mesa region. A second active trench extends from the second termination trench towards the first termination trench and terminates with a second tip region separated from the first termination trench by the termination mesa region. A first gate contact trench is connected to the first termination trench within the first edge region. A coupling trench is at a third edge region and is connected to the second termination trench, The coupling trench includes a corner portion that couples the coupling trench to the first gate contact trench.