Semiconductor Guard Ring Layout for Breakdown and Recovery Loss

Solution Overview

Problem

Conventional semiconductor devices face challenges in increasing breakdown strength and achieving favorable recovery characteristics due to sharp increases in current density and reverse recovery current, leading to increased recovery loss during switching operations.

Innovation Solution

The semiconductor device incorporates a semiconductor base body with a drift region, a dopant region, and a peripheral dopant region, where recombination centers are formed to reduce current density and prevent the flow of holes into the surface electrode, enhancing breakdown strength and recovery characteristics by controlling the dopant concentration and position of the peripheral dopant region.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a peripheral dopant region is formed to suppress breakdown at the outer peripheral end portion, then breakdown strength is improved, but current density sharply increases at switching giving rise to increased temperature and reduced breakdown strength

Engineering Contradiction:

Improvebreakdown strengthVSAvoidbreakdown strength

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent applies local quality by creating a guard ring region with specifically controlled dopant concentration that differs from both the element forming region and the peripheral dopant region. This localized dopant concentration gradient in the guard ring region selectively manages hole flow paths, allowing suppression of breakdown at the outer peripheral end while controlling the merging of currents to prevent sharp current density increases. The guard ring region's unique dopant profile (different from both adjacent regions) enables simultaneous optimization of breakdown strength and current density distribution.

Inventive Principle:

Principle #3Local quality

2Strength

If a peripheral dopant region is formed to suppress breakdown at the outer peripheral end portion, then breakdown strength is improved, but reverse recovery current sharply increases giving rise to increased recovery loss

Engineering Contradiction:

Improvebreakdown strengthVSAvoidrecovery loss

Core Design Contradiction:

StrengthVSLoss of energy

Solution Approach 1:

The patent applies local quality by creating a guard ring region with specifically controlled dopant concentration that differs from both the element forming region and the peripheral dopant region. This localized dopant concentration gradient in the guard ring region selectively manages hole flow paths, allowing suppression of breakdown at the outer peripheral end while controlling the merging of currents to prevent sharp current density increases. The guard ring region's unique dopant profile (different from both adjacent regions) enables simultaneous optimization of breakdown strength and current density distribution.

Inventive Principle:

Principle #3Local quality

3Strength

If the dopant concentration gradient at the outer peripheral end portion is lowered, then breakdown at the outer peripheral end portion is suppressed, but current density in the vicinity where currents merge is sharply increased

Engineering Contradiction:

Improvebreakdown strengthVSAvoidcurrent density control

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent applies local quality by creating a guard ring region with specifically controlled dopant concentration that differs from both the element forming region and the peripheral dopant region. This localized dopant concentration gradient in the guard ring region selectively manages hole flow paths, allowing suppression of breakdown at the outer peripheral end while controlling the merging of currents to prevent sharp current density increases. The guard ring region's unique dopant profile (different from both adjacent regions) enables simultaneous optimization of breakdown strength and current density distribution.

Inventive Principle:

Principle #3Local quality

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

The solution effectively reduces current density and temperature at the surface electrode, improves breakdown strength, and minimizes recovery loss by efficiently collecting holes at recombination centers and optimizing the dopant concentration and position of the peripheral dopant region.

Implementation Method 1

a plurality of recombination centers are formed in the semiconductor base body

Methodology Applied

Scientific EffectRecombination centers:

Implementation Method 2

the peripheral dopant region having dopant concentration higher than dopant concentration of the dopant region of the second conductive type

Methodology Applied

Scientific EffectDopant concentration gradient: Dopants

Data Source

PatentUS20240213308A1Semiconductor device

Publication Date: 2024.06.27 SHINDENGEN ELECTRIC MANUFACTURING CO LTD

AI summary

A semiconductor device includes, a semiconductor base body, an insulation layer that has an opening, and a surface electrode. The semiconductor base body includes a drift region, a p-type dopant region, and a peripheral dopant region. The p-type dopant region has a high concentration region that is formed in a region where the high concentration region overlaps with the p-type dopant region. A plurality of recombination centers are formed in the semiconductor base body, an inner peripheral end of the peripheral dopant region on the surface of the semiconductor base body is positioned on an inner peripheral side of an end portion of the opening, and a length from the inner peripheral end of the peripheral dopant region to the end portion of the opening is 0.01 μm or more to 130 μm or less.