Semiconductor Die Edge Termination With Shared Shield Potential

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Solution Overview

Problem

Existing edge termination structures in semiconductor dies face challenges in efficiently increasing breakdown voltage and dynamically ruggedness, especially at high doping levels and fast transients, due to limitations in potential distribution and shielding.

Innovation Solution

The implementation of a semiconductor die with a laterally arranged edge termination structure featuring a first inner shield electrode region and an outer shield electrode region, both electrically connected to a well region, allowing for a scalable and efficient potential tapping and distribution that shields the active area from backside drain potential, thereby enhancing breakdown voltage and dynamical ruggedness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional edge termination structures are used with multiple laterally staggered shield electrodes each having its own well region, then the breakdown voltage support increases, but the area required for the edge termination structure increases significantly and the potential difference between neighbouring shield electrodes decreases towards the lateral edge

Engineering Contradiction:
Improvebreakdown voltage supportVSAvoidedge termination area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

Multiple shield electrodes (first inner shield electrode and outer shield electrode) are electrically connected to a single common well region instead of each having its own separate well region. This merging approach maintains the breakdown voltage support while significantly reducing the area required for the edge termination structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single well region serves multiple functions: it provides the electrical potential for both the first inner shield electrode and the outer shield electrode, and it enables efficient potential distribution to multiple shield electrodes simultaneously, reducing the need for additional well regions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If more laterally staggered shield electrodes are added to increase breakdown voltage support, then the breakdown voltage increases, but the manufacturing complexity and doping level challenges increase

Engineering Contradiction:
Improvebreakdown voltage supportVSAvoidedge termination structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple shield electrodes are electrically connected to a single common well region, simplifying the manufacturing process by reducing the number of well regions that need to be formed and connected, thereby reducing doping level challenges and structural complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If shield electrodes are arranged to provide comprehensive shielding, then the dynamical ruggedness improves, but the area occupied by the edge termination structure increases

Engineering Contradiction:
Improvedynamical ruggednessVSAvoidedge termination area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

Multiple shield electrodes are electrically connected to a single common well region, providing comprehensive shielding for improved dynamical ruggedness while significantly reducing the area occupied by the edge termination structure compared to conventional designs with separate well regions.

Inventive Principle:
Principle #5Merging (Combining)

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

This design effectively increases the supported breakdown voltage and reduces the required edge termination area, while improving dynamical ruggedness by safely pinning the breakdown location in the active area, even during fast transients.

Implementation Method 1

the first inner shield electrode is electrically connected to tap an electrical potential from the well region. Additionally, the shield electrode of the outer shield electrode region is electrically connected to the first inner shield electrode

Methodology Applied
Scientific EffectElectrical potential tapping and transfer: Conduction (electrical)

Implementation Method 2

the edge termination structure can shield the active area from the backside drain potential that can for example reach up to the frontside at the edge of the die

Methodology Applied
Scientific EffectElectrical field shielding: Electric Field

Data Source

PatentEP4307391A1Semiconductor die and method of manufacturing the same
Publication Date: 2024.01.17 INFINEON TECH AUSTRIA AG
  • EP4307391A1 patent drawingFigure 1
  • EP4307391A1 patent drawingFigure 2
  • EP4307391A1 patent drawingFigure 3

AI summary

The present application relates to a semiconductor die (1) with a semiconductor device (2) and an edge termination structure (3) laterally between the semiconductor device (2) and a lateral edge (10) of the die (1), the edge termination structure (3) comprising a first inner shield electrode region (30) with a shield electrode (31) in a trench (33) extending into a semiconductor body (15), an outer shield electrode region (50) with a shield electrode (51) in a trench (53) extending into the semiconductor body (15) and disposed in a first lateral direction (11) between the first inner shield electrode region (30) and the lateral edge (10) of the die (1), a well region (60) formed in the semiconductor body (15) adjacent the trench (33) of the first inner shield electrode region (30), wherein the shield electrode (31) of the first inner shield electrode region (30) is electrically connected to the well region (60) to tap an electrical potential from the well region (60), and wherein the shield electrode (51) of the outer shield electrode region (50) is electrically connected to the shield electrode (31) of the first inner shield electrode region (30).