IGBT Semiconductor Structure With Barrier Doping and Deep Trench

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Solution Overview

Problem

The performance of current insulated gate bipolar transistors (IGBTs) is limited by high on-resistance and high turn-off energy loss due to weak carrier blocking and low hole concentration in the drift region.

Innovation Solution

A semiconductor structure is designed with a barrier doped region on the substrate and deep trench structure, accompanied by a first epitaxial layer with specific ion doping concentrations, to block carriers and enhance carrier collection, reducing on-resistance and turn-off energy loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional IGBT structure is used, then device simplicity is maintained, but on-resistance is high and turn-off energy loss is high

Engineering Contradiction:

Improveturn-off energy lossVSAvoidstructure complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The drift region is segmented into multiple zones with different doping concentrations (first doping concentration in lower portion, second doping concentration in upper portion). This segmentation allows optimized carrier blocking in different regions, reducing turn-off energy loss while maintaining manageable structural complexity through systematic zonation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the drift region are assigned different local properties: the lower portion has higher doping concentration for carrier blocking, while the upper portion has lower doping concentration for reduced on-resistance. This local quality differentiation resolves the contradiction by optimizing each region's function rather than using uniform structure.

Inventive Principle:

Principle #3Local quality

2Reliability

If uniform doping concentration is used in drift region, then manufacturing simplicity is maintained, but carrier blocking is weak and hole concentration is low

Engineering Contradiction:

Improvecarrier blockingVSAvoiddoping uniformity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The doping concentration parameter is changed across different regions of the drift region. The lower portion uses first doping concentration for strong carrier blocking, while the upper portion uses second doping concentration for adequate hole concentration. This parameter variation improves reliability without excessive manufacturing complexity by using standard doping techniques with controlled gradients.

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If higher doping concentration is used in drift region, then hole concentration increases, but on-resistance increases and on-state voltage drop increases

Engineering Contradiction:

Improvehole concentrationVSAvoidon-state voltage drop

Core Design Contradiction:

Quantity of substanceVSLoss of energy

Solution Approach 1:

The drift region employs local quality differentiation where the lower portion has higher doping concentration to generate adequate hole concentration for carrier blocking, while the upper portion has lower doping concentration to minimize on-resistance and on-state voltage drop. This spatial differentiation of doping quality resolves the contradiction between hole concentration and energy loss.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The doping concentration is varied along the vertical dimension of the drift region rather than being uniform. This dimensional variation allows the lower portion to provide holes while the upper portion maintains low resistance, effectively decoupling the conflicting requirements through spatial separation in the vertical dimension.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 structure improves IGBT performance by reducing on-state voltage drop and turn-off energy loss, enhancing carrier blocking and increasing carrier concentration in the drift region.

Implementation Method 1

the barrier doped region is spaced apart from the body region, the source region and the gate structure by a part of the first epitaxial layer... carriers (injected from the collector region) entering the body region through the deep trench structure can be blocked by the barrier doped region

Methodology Applied

Scientific EffectCarrier blocking:

Implementation Method 2

a substrate doped with a first ion... the deep trench structure is doped with a second ion... the barrier doped region is doped with a third ion... the first epitaxial layer is doped with a fourth ion

Methodology Applied

Scientific EffectIon doping: Ion Implantation

Data Source

PatentUS12527053B2Semiconductor structure and method of forming the same

Publication Date: 2026.01.13 SHANGHAI HUAHONG GRACE SEMICON MFG CORP

AI summary

The present disclosure provides a semiconductor structure and a method of forming the same. The semiconductor structure includes: a substrate doped with a first ion, a deep trench structure disposed in the substrate, a barrier doped region disposed on a top of the substrate and the deep trench structure, a first epitaxial layer disposed on the barrier doped region, a body region disposed in the first epitaxial layer, a source region disposed in the body region, a gate structure disposed in the first epitaxial layer, and a collector region disposed at a bottom of the substrate. By means of the semiconductor structure, performance of an insulated gate bipolar transistor can be improved.