Semiconductor Drift Regions for Breakdown Voltage
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Solution Overview
Problem
Current semiconductor devices are constrained by their breakdown voltage, limiting the rated drain-to-source voltage and requiring significant design and manufacturing margins to accommodate variations and fluctuations, which restricts the operational range and efficiency.
Innovation Solution
The semiconductor device structure incorporates a body region with junction isolation and drift regions that distribute drain voltage laterally and vertically, enhancing breakdown voltage through p-n junction isolation and double reduced surface field effects, thereby increasing the rated drain-to-source breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rated drain-to-source voltage is set below the breakdown voltage to provide sufficient margin, then the device operates reliably with accommodation for variations and fluctuations, but the operational range and efficiency are restricted
Solution Approach 1:
The patent changes the electrical parameters of the semiconductor device by introducing drift regions with specific doping concentrations and geometries, which directly increases the breakdown voltage parameter. This allows the rated voltage to be increased while maintaining reliability margins, thus expanding the operational range without sacrificing reliability.
Solution Approach 2:
The patent introduces lateral drift regions that extend in the lateral dimension between the drain and the p-n junction isolation region. This dimensional extension distributes the voltage stress laterally, increasing the breakdown voltage and allowing higher rated voltages while maintaining reliability.
2Reliability
If drift regions are introduced to distribute drain voltage laterally and vertically, then the breakdown voltage is enhanced and operational margin is increased, but the device structure becomes more complex
Solution Approach 1:
The patent segments the drift region into multiple zones with different doping concentrations (first drift region with lower doping, second drift region with higher doping). This segmentation allows optimized voltage distribution while using standard semiconductor fabrication techniques, balancing performance improvement with manufacturing feasibility.
Solution Approach 2:
The drift regions serve multiple functions: they distribute voltage laterally and vertically, provide conductive paths for current, and enable higher breakdown voltage. This multi-functionality justifies the added structural elements by delivering multiple benefits from a single design feature.
3Reliability
If junction isolation region is used to provide p-n junction isolation, then current flow between body region and surrounding regions is prevented, but the lateral voltage distribution is constrained
Solution Approach 1:
The patent introduces drift regions as intermediary structures between the drain and the p-n junction isolation region. These drift regions act as mediators that laterally distribute the voltage before it reaches the isolation junction, reducing the voltage stress at the isolation region while maintaining its effectiveness.
Solution Approach 2:
The patent extends the voltage distribution into the lateral dimension by introducing lateral drift regions that span between the drain and the isolation region. This lateral extension allows voltage to be distributed across a greater distance, reducing the electric field intensity at critical junctions while maintaining isolation effectiveness.
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 configuration significantly reduces lateral and vertical electrical stress, allowing for a higher breakdown voltage, increased operational margin, and improved reliability of semiconductor devices.
Implementation Method 1
the junction isolation region provides p-n junction isolation that prevents the flow of current between the body region and the surrounding regions of the same conductivity
Implementation Method 2
the voltage applied to a semiconductor device is constrained by the breakdown voltage of the device, which is the minimum applied voltage that causes avalanche breakdown in the device
Data Source
AI summary
Semiconductor device structures and related fabrication methods are provided. An exemplary semiconductor device structure includes a body region of semiconductor material having a first conductivity type, a source region of semiconductor material having a second conductivity type within the body region, a junction isolation region of semiconductor material having the second conductivity type, a drain region of semiconductor material having the second conductivity type, and first and second drift regions of semiconductor material having the second conductivity type. The first drift region resides laterally between the drain region and the junction isolation region, the junction isolation region resides laterally between the first drift region and the second drift region, and the second drift region resides laterally between the body region and the junction isolation region.