High Voltage Semiconductor Device Drift Region Segmentation
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Solution Overview
Problem
Conventional high voltage semiconductor devices face challenges in improving breakdown voltage and on-current while minimizing leakage current and device size, as increasing the drift region size enhances leakage current and reducing the device isolation region size increases overall device size.
Innovation Solution
The semiconductor device incorporates a first drift region adjacent to the gate electrode, a second drift region with higher impurity concentration between the first drift region and the drain, and an insulating region with higher electrical resistance between the first drift region and the device isolation region, allowing for improved breakdown voltage and reduced leakage current, while maintaining a compact device size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the size of the drift region is increased to improve breakdown voltage, then breakdown voltage is improved, but leakage current increases and on-current is reduced
Solution Approach 1:
The drift region is divided into two separate drift regions with different impurity concentrations. The first drift region has lower impurity concentration for high breakdown voltage, while the second drift region has higher impurity concentration to reduce leakage current and improve on-current. This segmentation allows each region to optimize for its specific function.
Solution Approach 2:
Different regions of the drift structure are assigned different impurity concentrations tailored to their specific functional requirements. The first drift region (near the gate) has low impurity concentration for voltage breakdown control, while the second drift region (near the drain) has high impurity concentration for current conduction and leakage reduction.
2Object-generated harmful factors
If the size of the device isolation region is increased to reduce leakage current, then leakage current is reduced, but the overall size of the device increases
Solution Approach 1:
Instead of increasing the physical size of the device isolation region, the invention changes the impurity concentration parameter in the drift regions. The higher impurity concentration in the second drift region reduces leakage current through improved carrier control, achieving leakage reduction without increasing device footprint.
3Strength
If the size of the drift region is increased to improve breakdown voltage, then breakdown voltage is improved, but on-current is reduced
Solution Approach 1:
The drift region is segmented into two parts with different impurity concentrations. The first drift region maintains low impurity concentration for high breakdown voltage, while the second drift region has high impurity concentration to provide low resistance for current flow, thus improving on-current without compromising breakdown voltage.
Solution Approach 2:
The impurity concentration is locally optimized in different drift region segments. The first drift region has low impurity concentration for voltage control, while the second drift region has high impurity concentration for current conduction, allowing simultaneous optimization of breakdown voltage and on-current.
Data Source
AI summary
A high voltage semiconductor device includes a gate electrode structure disposed on a substrate, a source region disposed in the substrate to be adjacent to one side of the gate electrode structure, a first drift region disposed in the substrate to be adjacent to another side of the gate electrode structure, a drain region electrically connected with the first drift region, and a device isolation region disposed on one side of the drain region. Particularly, the first drift region is spaced apart from the device isolation region.