MOS Device Doped Regions for Independent Voltage Operation
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Solution Overview
Problem
The existing LDMOSFET semiconductor devices face challenges in establishing a differential voltage between the source and body regions due to their electrical connection, limiting design flexibility and application versatility.
Innovation Solution
A semiconductor device design featuring separated source and body regions with specific doped regions and a field plate structure, allowing for independent voltage operation and enhanced breakdown voltage, achieved through a method involving doped wells and regions with controlled doping concentrations and insulator-conductive member configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If source and body regions are electrically connected by metal layers or heavily-doped semiconductor deep well, then device reliability is improved, but the ability to establish differential voltage between source and body regions is lost
Solution Approach 1:
The patent divides the previously connected source and body regions into electrically isolated segments using separate doped regions (first doped region for source, second doped region for body) with different conductivity types. This segmentation allows independent voltage control while maintaining device functionality, resolving the contradiction between reliability and voltage differential capability.
Solution Approach 2:
The patent introduces intermediary structures including isolation regions and specific doped regions that mediate between the source and body regions. These intermediary elements enable electrical isolation while providing controlled interaction paths, allowing differential voltage operation without compromising overall device reliability.
2Adaptability or versatility
If source and body regions are separated to enable differential voltage operation, then design flexibility is improved, but device complexity increases
Solution Approach 1:
The patent merges multiple functions into the doped region structure: the first and second doped regions simultaneously serve as source/body regions, provide electrical isolation, and establish differential voltage capability. This functional merging reduces the need for separate isolation structures and simplifies the overall device architecture despite the increased functionality.
Solution Approach 2:
The doped regions are designed to perform multiple functions: they serve as active source/body regions, provide electrical isolation from each other, establish voltage differentials, and control carrier flow. This multi-functionality reduces the number of separate components needed, thereby managing device complexity while achieving design flexibility.
3Strength
If doped regions with different conductivity types are used to separate source and body regions, then breakdown voltage is improved, but ON-resistance increases
Solution Approach 1:
The patent applies different doping concentrations and conductivity types in specific local regions: the first doped region has one conductivity type while the second doped region has another, with carefully controlled doping profiles. This local differentiation creates high breakdown voltage at the interface while maintaining low resistance in the bulk regions, resolving the contradiction between breakdown voltage and ON-resistance.
Solution Approach 2:
The patent optimizes doping parameters including concentration, depth, and lateral distribution of the first and second doped regions. By adjusting these parameters, the device achieves high breakdown voltage through appropriate doping profiles while minimizing ON-resistance through optimized carrier concentration in the conductive paths.
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
Enables independent voltage operation of source and body regions, increasing design flexibility and application versatility while improving breakdown voltage and reducing ON-resistance.
Implementation Method 1
a first doped region having a second conductivity type, the first doped region disposed between the source region and the doped well; and a second doped region having the first conductivity type and disposed under the source region
Implementation Method 2
a doped well disposed in the semiconductor layer and having a first conductivity type... improving breakdown voltage
Data Source
AI summary
A semiconductor device is provided. The device may include a semiconductor layer; and a doped well disposed in the semiconductor layer and having a first conductivity type. The device may also include a drain region, a source region, and a body region, where the source and body regions may operate in different voltages. Further, the device may include a first doped region having a second conductivity type, the first doped region disposed between the source region and the doped well; and a second doped region having the first conductivity type and disposed under the source region. The device may include a third doped region having the second conductivity type and disposed in the doped well; and a fourth doped region disposed above the third doped region, the fourth doped region having the first conductivity type. Additionally, the device may include a gate and a field plate.