Semiconductor Super Junction Barrier Layer Segmentation
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Solution Overview
Problem
The concentration of the n-type barrier layer in IGBTs is limited by the need to suppress breakdown, restricting the reduction of saturation voltage and improvement of semiconductor device characteristics.
Innovation Solution
A semiconductor device design featuring a super junction structure with an n-type barrier layer and p-type diffusion layer alternately arranged, forming a protruding configuration, which increases the impurity concentration of the n-type barrier layer to enhance carrier blocking and reduce on-resistance while mitigating avalanche breakdown.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the concentration of the n-type barrier layer is increased to suppress carrier emission and reduce saturation voltage, then the saturation voltage decreases, but breakdown occurs between the n-type barrier layer and the p-type base layer
Solution Approach 1:
The invention divides the barrier structure into multiple segments: a first barrier layer with lower concentration directly under the p-type base layer, and a second barrier layer with higher concentration beneath the first barrier layer. This segmentation allows each layer to perform its specific function - the first layer prevents breakdown while the second layer suppresses carrier emission, resolving the contradiction between reducing saturation voltage and preventing breakdown.
Solution Approach 2:
The invention applies different impurity concentrations to different regions of the barrier structure. The first barrier layer has a lower impurity concentration (1×10^16 to 1×10^18 atoms/cm³) to prevent breakdown at the interface with the p-type base layer, while the second barrier layer has a higher impurity concentration (1×10^18 to 1×10^20 atoms/cm³) to effectively suppress carrier emission. This local differentiation of properties resolves the contradiction by optimizing each region for its specific function.
2Reliability
If the concentration of the n-type barrier layer is increased to improve carrier blocking, then carrier blocking improves, but breakdown between layers occurs
Solution Approach 1:
The barrier structure is segmented into two functional layers: the first barrier layer provides electrical isolation and prevents breakdown with controlled lower concentration, while the second barrier layer provides strong carrier blocking with higher concentration. This segmentation enables both carrier blocking and breakdown prevention to be achieved simultaneously through differentiated design.
Solution Approach 2:
Different impurity concentrations are assigned to different barrier layers based on their specific functions. The first barrier layer uses lower concentration (1×10^16 to 1×10^18 atoms/cm³) optimized for preventing breakdown at the p-type base layer interface, while the second barrier layer uses higher concentration (1×10^18 to 1×10^20 atoms/cm³) optimized for carrier blocking. This local quality differentiation resolves the contradiction between carrier blocking and breakdown prevention.
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 design allows for increased impurity concentration of the n-type barrier layer, reducing saturation voltage and improving semiconductor device performance by enhancing carrier blocking and reducing on-resistance.
Implementation Method 1
mitigating avalanche breakdown
Implementation Method 2
enhance carrier blocking and reduce on-resistance
Data Source
AI summary
According to one embodiment, a semiconductor device includes a first main electrode, a base layer of a first conductivity type, a barrier layer of the first conductivity type, a diffusion layer of a second conductivity type, a base layer of the second conductivity type, a first conductor layer, a second conductor layer, and a second main electrode. Bottoms of the barrier layer of the first conductivity type and the diffusion layer of the second conductivity type are positioned on the first main electrode side of lower ends of the first conductor layer and the second conductor layer. The barrier layer of the first conductivity type and the diffusion layer of the second conductivity type form a super junction proximally to tips of the first conductor layer and the second conductor layer.