Structured Barrier Region Diode Anode Injection Efficiency
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Solution Overview
Problem
Power semiconductor devices, such as RC IGBTs and diodes, face challenges in achieving efficient reverse conductivity and anode injection efficiency due to limitations in their diode structures, particularly in controlling the coupling between the body and drift regions.
Innovation Solution
A power semiconductor device with a diode section featuring a laterally structured highly doped barrier region between the body and drift regions, where the barrier region has a dopant concentration at least 100 times greater than the drift region and a dopant dose higher than the body region, ensuring at least 50% of the body region is coupled to the drift region through the barrier and an additional 5% without it, enhancing anode efficiency and current handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional diode structure with uniform doping is used, then the manufacturing process is simple, but the anode injection efficiency is insufficient and plasma concentration varies significantly
Solution Approach 1:
The patent applies local quality by creating a laterally structured barrier region with different dopant concentrations in specific areas. The barrier region has a first portion with a first dopant concentration and a second portion with a second dopant concentration, allowing different regions to perform different functions: the first portion provides high injection efficiency while the second portion controls plasma concentration variations, thereby resolving the contradiction between efficiency and uniformity.
Solution Approach 2:
The barrier region is segmented into multiple portions with different doping characteristics. This segmentation allows the diode section to have both high anode injection efficiency (from the first portion) and reduced plasma concentration variations (from the second portion), solving the technical contradiction without requiring complete structural redesign.
2Reliability
If the barrier region has high dopant concentration throughout, then anode injection efficiency improves, but plasma concentration variations increase
Solution Approach 1:
The barrier region implements local quality by having a first portion with high dopant concentration (10^19 to 10^21 atoms/cm³) for high anode injection efficiency, and a second portion with different dopant concentration (10^16 to 10^18 atoms/cm³) for stable plasma concentration. This spatial differentiation resolves the contradiction between efficiency and compositional stability.
Solution Approach 2:
The barrier region is divided into functionally distinct segments: the first portion optimized for charge injection and the second portion optimized for plasma concentration control. This segmentation enables simultaneous achievement of high injection efficiency and stable plasma characteristics.
3Reliability
If the body region is completely coupled to drift region through barrier, then anode efficiency increases, but current handling capability is limited
Solution Approach 1:
The coupling between body region and drift region is segmented into two pathways: one through the barrier region (first portion) for high efficiency injection, and another direct coupling path for enhanced current handling. This segmented approach resolves the contradiction between efficiency and productivity by providing multiple current paths with different characteristics.
Solution Approach 2:
The barrier region acts as an intermediary structure that mediates the coupling between body and drift regions. By carefully designing the barrier's lateral structure with different dopant concentrations, it enables both high emitter efficiency (through the first portion) and adequate current handling (through the second portion and direct coupling paths).
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 improves the anode injection efficiency and current handling capabilities of the diode section, reducing plasma concentration variations and enabling precise control over emitter efficiency, addressing the limitations of existing diode structures in power semiconductor devices.
Implementation Method 1
the barrier region has a dopant concentration at least 100 times greater than the average dopant concentration of the drift region and a dopant dose greater than a dopant dose of the body region
Data Source
AI summary
A power device includes: a diode section; a semiconductor body; a drift region extending into the diode section; trenches in the diode section and extending along a vertical direction into the semiconductor body, two adjacent trenches defining a respective mesa portion in the semiconductor body; a body region in the mesa portions; in the diode section, a barrier region between the body and drift regions and having a dopant concentration at least 100 times greater than an average dopant concentration of the drift region and a dopant dose greater than that of the body region. The barrier region has a lateral structure according to which at least 50% of the body region in the diode section is coupled to the drift region at least by the barrier region, and at least 5% of the body region in the diode section is coupled to the drift region without the barrier region.