Buffer Region Doping Profile for Low On-Voltage IGBTs
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Solution Overview
Problem
Existing semiconductor apparatuses face challenges in optimizing the buffer layer configuration, particularly the field stop layer, which affects the performance and reliability of components like IGBTs, leading to inefficiencies in current flow and voltage management.
Innovation Solution
The implementation of a buffer region with a specific doping concentration distribution, including a hydrogen ion implantation technique to create a field stop layer that enhances carrier injection and reduces on-voltage, while maintaining a controlled depletion layer to prevent breakdown, is introduced.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a buffer layer is provided in a semiconductor apparatus, then breakdown voltage is improved, but on-voltage increases
Solution Approach 1:
The patent applies local quality by creating a buffer layer with non-uniform doping concentration distribution. The doping concentration is higher near the drift region interface and gradually decreases toward the collector region, allowing the buffer layer to simultaneously provide high breakdown voltage where needed while maintaining low on-voltage through the gradual transition. This graded doping profile optimizes both contradictory requirements by making different parts of the buffer layer serve different functions.
Solution Approach 2:
The patent employs parameter changes by varying the doping concentration parameter throughout the buffer layer. Instead of using a uniform doping concentration, the doping concentration is changed gradually from one region to another, creating an optimized profile that balances breakdown voltage and on-voltage characteristics. This continuous parameter variation allows the system to achieve both high strength and low power consumption.
2Strength
If the doping concentration in the buffer layer is increased, then breakdown voltage is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-planning and pre-designing the optimal doping concentration profile before manufacturing. The graded doping profile is carefully designed in advance with specific concentration values at different positions, allowing the manufacturing process to follow a predetermined plan. This reduces manufacturing complexity by providing clear guidance for doping process parameters while achieving the desired high breakdown voltage.
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 approach improves the breakdown voltage and reduces on-voltage, thereby enhancing the performance and reliability of semiconductor apparatuses by optimizing the buffer layer's functionality.
Implementation Method 1
a buffer region with a specific doping concentration distribution, including a hydrogen ion implantation technique to create a field stop layer
Data Source
AI summary
Provided is a semiconductor apparatus, wherein a doping concentration distribution in the buffer region has a deepest slope where a doping concentration monotonically decreases to a position where it comes in contact with the drift region in a direction from the lower surface of the semiconductor substrate toward an upper surface, a hydrogen chemical concentration distribution in the buffer region includes in a first depth range provided with the slope: a first decrease portion where a hydrogen chemical concentration decreases toward the upper surface side; a second decrease portion located closer to the upper surface side than the first decrease portion is and where the chemical concentration decreases; and an intermediate portion arranged between the first and second decrease portions, and the intermediate portion has: a flat portion where the distribution is uniform; a peak in a slope of the chemical concentration; or a kink portion of the chemical concentration.