Field Electrode Structure for Semiconductor On-State Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power semiconductor devices, such as IGFETs and IGBTs, face challenges in minimizing ohmic losses while maintaining high dopant concentrations in the drift zone, which affects their on-state resistance and blocking capabilities.
Innovation Solution
The semiconductor device incorporates a mesa section with a rectifying structure and a first drift zone, surrounded by a field electrode structure with a field electrode and dielectric, where the maximum horizontal extension of the field electrode is limited to 500 nm or less, allowing for higher dopant concentrations without adverse impact on blocking capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If higher dopant concentrations are used in the drift zone, then on-state resistance is reduced, but blocking capabilities are adversely impacted
Solution Approach 1:
The drift zone is divided into multiple sections with different doping concentrations. The first drift zone section has a higher dopant concentration to reduce on-state resistance, while the second drift zone section has a lower dopant concentration to maintain blocking capabilities. This segmentation allows each region to be optimized for its specific function.
Solution Approach 2:
Different regions of the drift zone are assigned different dopant concentrations based on their functional requirements. The mesa section contains a first drift zone section with higher doping for low resistance, while regions under the field electrode structure contain a second drift zone section with lower doping for high voltage blocking. This local quality variation resolves the contradiction between low on-state resistance and high blocking capability.
2Loss of energy
If the field electrode horizontal extension is reduced to 500 nm or less, then output capacitance is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The field electrode horizontal extension is optimized to a specific parameter range (500 nm or less) to achieve the desired reduction in output capacitance. This parameter change balances the competing requirements of low capacitance and manufacturability by establishing a clear design target that guides the fabrication process.
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 reduces on-state resistance and output capacitance, making the semiconductor device suitable for applications like switched mode power supplies and motor drives by minimizing ohmic losses and maintaining efficient voltage blocking.
Implementation Method 1
a field dielectric sandwiched between the field electrode and the semiconductor body
Implementation Method 2
Each mesa section includes a rectifying structure and a first drift zone section
Data Source
AI summary
According to an embodiment a semiconductor device includes a semiconductor body with a mesa section that may include a rectifying structure and a first drift zone section. The mesa section surrounds a field electrode structure that includes a field electrode and a field dielectric sandwiched between the field electrode and the semiconductor body. A maximum horizontal extension of the field electrode in a measure plane parallel to a first surface of the semiconductor body is at most 500 nm.