Semiconductor Device Doping Segmentation for Loss Reduction
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Solution Overview
Problem
Conventional semiconductor devices, such as IGBTs, face challenges in improving turn-on loss characteristics, with existing technologies failing to effectively optimize doping concentrations and region structures to enhance performance.
Innovation Solution
A semiconductor device design featuring a semiconductor substrate with a transistor portion and a diode portion, incorporating specific doping concentration profiles and region structures, including trench portions, mesa portions, and floating regions, to optimize doping concentrations and carrier implantation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional doping structures are used in semiconductor devices, then manufacturing simplicity is maintained, but turn-on loss characteristics deteriorate
Solution Approach 1:
The drift region is segmented into multiple regions with different doping concentrations (first doping concentration region and second doping concentration region), allowing optimized carrier distribution to reduce turn-on loss while maintaining manageable structural complexity through systematic segmentation
Solution Approach 2:
Different regions of the semiconductor device are assigned different doping concentrations locally - the first doping concentration region has higher concentration than the drift region, while the second doping concentration region has lower concentration, optimizing performance characteristics at specific locations without requiring complete structural redesign
2Reliability
If higher doping concentrations are used to improve conductivity, then on-state voltage is reduced, but reverse recovery characteristics deteriorate
Solution Approach 1:
The doping structure is segmented into multiple concentration regions, allowing the device to achieve low on-state voltage through the first doping concentration region while maintaining good reverse recovery characteristics through the second doping concentration region with lower doping
Solution Approach 2:
The doping concentration parameter is changed across different regions - higher concentration in the first region reduces on-state voltage, while lower concentration in the second region improves reverse recovery characteristics, allowing both requirements to be satisfied simultaneously through parameter variation
3Productivity
If uniform doping concentration is used throughout the drift region, then manufacturing simplicity is maintained, but carrier implantation efficiency deteriorates
Solution Approach 1:
The drift region is divided into multiple doping concentration regions with different concentrations, enabling optimized carrier implantation efficiency through the first doping concentration region while maintaining acceptable manufacturing complexity through the second doping concentration region
4Loss of energy
If doping concentration is increased to reduce off-state loss, then off-state loss is reduced, but latch-up susceptibility increases
Solution Approach 1:
The doping structure is segmented into regions with different concentrations, allowing off-state loss reduction through the first doping concentration region while maintaining latch-up suppression through the second doping concentration region with lower doping that reduces electric field concentration
Solution Approach 2:
Different regions have different doping concentrations optimized for different functions - the first doping concentration region optimizes for off-state loss reduction, while the second doping concentration region optimizes for latch-up suppression through lower concentration that reduces electric field effects
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 design improves turn-on loss characteristics and reverse recovery characteristics by regulating doping concentrations and carrier implantation, reducing on-state voltage and off-state loss while suppressing latch-ups and leakage current.
Implementation Method 1
one or more first conductivity-type accumulation regions that are provided in each of the mesa portions and between the base region and the drift region and have doping concentrations higher than that of the drift region
Implementation Method 2
optimize doping concentrations and carrier implantation efficiency
Data Source
AI summary
A semiconductor device includes: a semiconductor substrate having a first conductivity-type drift region; a transistor portion; and a diode portion, wherein the transistor portion and the diode portion each have: a second conductivity-type base region; a plurality of trench portions penetrating the base region and having conductive portions provided therein; and a mesa portion sandwiched by trench portions, the transistor portion has one or more first conductivity-type accumulation regions that have doping concentrations higher than that of the drift region, the diode portion has one or more first conductivity-type high concentration regions that have doping concentrations higher than that of the drift region, and an integrated concentration of the doping concentrations of the accumulation regions is higher than an integrated concentration of the doping concentrations of the one or more high concentration regions of the mesa portion of the diode portion.