Bipolar Semiconductor Device Junction Termination
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Solution Overview
Problem
Bipolar semiconductor devices, such as speed diodes, face challenges in achieving high surge current strength and dynamic robustness while minimizing operational losses, with existing diodes like CAL and EMCON diodes having limitations in surge current strength and dynamic robustness.
Innovation Solution
The semiconductor device incorporates a structure with a first semiconductor region of a first conductivity type, a second semiconductor region of a second conductivity type forming a pn-junction, and a plurality of third semiconductor regions with higher doping concentrations, each equipped with junction termination structures like field plate structures to reduce electric field strength during switching operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a heavily doped p-type emitter is used in CAL diodes, then surge current strength is improved, but manufacturing complexity increases due to intensive helium irradiation and additional methods for reducing charge carrier lifetime
Solution Approach 1:
The patent changes the doping concentration parameter of the emitter region, using a moderately doped emitter (10^16 to 10^18 atoms/cm³) instead of heavily doped, and introduces a graded doping profile in the base region to achieve high surge current strength without complex manufacturing processes
Solution Approach 2:
The patent implements local quality by creating a graded doping profile in the base region where doping concentration varies spatially, and by introducing localized highly doped regions at specific positions to optimize both surge current strength and manufacturing simplicity
2Ease of manufacture
If a weakly p-doped emitter is used in EMCON diodes, then manufacturing is simplified, but surge current strength is reduced
Solution Approach 1:
The patent optimizes the emitter doping concentration to a moderate range (10^16 to 10^18 atoms/cm³) that balances ease of manufacture with adequate surge current strength, and uses graded base region doping to compensate for the moderate emitter doping level
Solution Approach 2:
The patent creates a composite doping structure with multiple regions of different doping concentrations (moderately doped emitter, graded base with varying concentrations, and highly doped localized regions) to achieve superior performance compared to uniform doping structures
3Strength
If highly p-doped zones are introduced in speed diodes to increase surge current strength, then surge energy capacity is improved, but dynamic robustness deteriorates
Solution Approach 1:
The patent applies local quality by introducing highly doped regions only at specific localized positions within the base region rather than uniformly throughout, and uses graded doping profiles in other areas to maintain dynamic robustness while achieving high surge current strength at critical locations
Solution Approach 2:
The patent segments the base region into multiple zones with different doping concentrations, creating a graded structure where highly doped regions are separated and distributed at specific positions, allowing optimization of both surge current strength and dynamic robustness in different spatial locations
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 configuration enhances the semiconductor device's surge current strength and dynamic robustness, reducing the risk of avalanche breakdown and improving reverse recovery characteristics, while maintaining low forward voltage drop.
Implementation Method 1
a second semiconductor region of a second conductivity type forming a pn-junction with the first semiconductor region
Implementation Method 2
each of which is provided with at least one respective junction termination structure
Implementation Method 3
reducing the risk of avalanche breakdown
Data Source
AI summary
A bipolar semiconductor device and method are provided. One embodiment provides a bipolar semiconductor device including a first semiconductor region of a first conductivity type having a first doping concentration, a second semiconductor region of a second conductivity type forming a pn-junction with the first semiconductor region, and a plurality of third semiconductor regions of the first conductivity type at least partially arranged in the first semiconductor region and having a doping concentration which is higher than the first doping concentration. Each of the third semiconductor regions is provided with at least one respective junction termination structure.