Semiconductor Edge Termination via Segmented Doping
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Solution Overview
Problem
Existing semiconductor die designs suffer from electric field concentration at edges, leading to reduced breakdown voltage and increased leakage current, especially under thermal stress, which current edge termination structures fail to adequately address.
Innovation Solution
Incorporating a drift region with a charge compensation region, guard rings, and a counter doping region of opposite doping type, which reduces electric field concentration and improves the performance of semiconductor die by optimizing breakdown voltage and leakage current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional edge termination structures are used, then manufacturing is simpler, but electric field concentration at edges increases leading to reduced breakdown voltage and increased leakage current
Solution Approach 1:
The edge termination structure is segmented into multiple functional regions: a charge compensation region with first doping type, a charge generation region with second doping type, and guard rings with third doping type. This segmentation allows each region to address specific electric field issues independently, achieving superior field control while maintaining manageable manufacturing complexity through modular design
Solution Approach 2:
Different doping types and concentrations are applied to different locations within the edge termination region. The charge compensation region uses one doping type to neutralize excess charges, the charge generation region uses another doping type to generate compensating charges, and guard rings use a third doping type to further control field distribution. This local differentiation of material properties optimizes electric field management at each specific location
2Reliability
If conventional edge termination structures are used, then device complexity is lower, but leakage current under thermal stress increases significantly
Solution Approach 1:
The edge termination structure is divided into specialized regions including charge compensation, charge generation, and guard rings, each with specific doping types. This segmentation enables targeted control of leakage mechanisms at different locations, effectively suppressing thermal stress-induced leakage current while keeping the overall structure manageable through functional modularity
Solution Approach 2:
The charge compensation region and charge generation region act as intermediary zones between the active region and the edge termination. These intermediary regions with specific doping types gradually transition the electric field distribution, preventing abrupt field changes that would cause leakage, thereby reducing thermal stress effects without requiring complete redesign of the entire device
3Manufacturing precision
If existing edge termination structures are used, then manufacturing process is simpler, but electric field concentration reduces breakdown voltage
Solution Approach 1:
The doping structure is segmented into distinct regions with specific doping types: charge compensation region, charge generation region, and guard rings. This segmentation enables precise control of electric field distribution and breakdown voltage characteristics while maintaining manufacturing feasibility through standardized doping processes applied to each segment
Solution Approach 2:
Different doping types and concentrations are applied to different regions to precisely control electric field parameters. The charge compensation region uses one doping concentration, the charge generation region uses another, and guard rings use a third concentration. This parameter differentiation allows precise tuning of breakdown voltage while keeping manufacturing processes manageable
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 described edge termination structure effectively reduces electric field concentration, enhancing the semiconductor die's breakdown voltage and leakage current performance, with leakage current less than 1 μAcm² at rated voltages over 600 V under constant bias and thermal stress.
Implementation Method 1
The charge compensation region is in the drift region and has a second doping type that is opposite the first doping type
Implementation Method 2
The guard rings are in the charge compensation region, have the second doping type, and a doping concentration that is greater than a doping concentration of the charge compensation region
Implementation Method 3
The counter doping region is in the drift region and overlaps at least a portion of the charge compensation region. The counter doping region has the first doping type
Data Source
AI summary
A semiconductor die includes a drift region, an active region in the drift region, and an edge termination region surrounding the active region in the drift region. The drift region has a first doping type. The edge termination region includes a charge compensation region, a number of guard rings, and a counter doping region. The charge compensation region is in the drift region and has a second doping type that is opposite the first doping type. The guard rings are in the charge compensation region, have the second doping type, and a doping concentration that is greater than a doping concentration of the charge compensation region. The counter doping region is in the drift region and overlaps at least a portion of the charge compensation region. The counter doping region has the first doping type.