Doped Isolation Region for High-Voltage Semiconductor Breakdown
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Solution Overview
Problem
Conventional high-voltage integrated circuit (HVIC) devices face challenges such as latch-up effect, low punch-through voltage, low switching speed, and large device area, limiting their performance and efficiency.
Innovation Solution
A semiconductor device with a substrate structure that includes a high side region, a low side region, a level shift region, and an isolation region, where a doped isolation region with a first conductive type is disposed between the low side and high side regions, with a depth and dopant concentration that decreases linearly from the central to the peripheral region, enhancing breakdown voltage and suppressing lateral punch-through leakage current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional isolation structure is used to separate high voltage and low voltage regions, then device integration is simplified, but lateral punch-through leakage current increases and breakdown voltage decreases
Solution Approach 1:
The patent applies local quality by creating a doped isolation region with non-uniform dopant concentration distribution. Specifically, the dopant concentration is highest at the interface with the high voltage region and decreases toward the low voltage region, creating locally optimized electrical properties that suppress leakage current while maintaining high breakdown voltage.
Solution Approach 2:
The patent changes the dopant concentration parameter within the isolation region, creating a gradient from high concentration near the high voltage region to low concentration near the low voltage region. This parameter variation enables the isolation region to simultaneously achieve low leakage current and high breakdown voltage by optimizing the electrical characteristics at different locations.
2Object-generated harmful factors
If the isolation region width is increased to suppress leakage current, then lateral punch-through leakage is reduced, but device area increases
Solution Approach 1:
Instead of increasing the isolation region width, the patent changes the dopant concentration parameter within the existing width. By creating a dopant gradient with highest concentration at the high voltage interface, the patent achieves effective leakage suppression without expanding the device footprint.
Solution Approach 2:
The patent concentrates the dopant concentration locally at the critical interface region where leakage occurs, rather than uniformly distributing dopants throughout the entire isolation region. This localized doping approach efficiently suppresses leakage current while minimizing the required isolation region width.
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 semiconductor device improves breakdown voltage and reduces lateral punch-through leakage current, addressing the limitations of conventional HVIC devices by optimizing the substrate structure and dopant distribution.
Implementation Method 1
a doped isolation region having a first conductive type is disposed in the isolation region. The doped isolation region includes a first doped portion and a second doped portion adjacent to the first doped portion. The depth of the first doped portion is decreased linearly along a first direction from the isolation region to the level shift region. The depth of the second doped portion is decreased linearly along a second direction from the isolation region to the high side region.
Data Source
AI summary
A semiconductor device is disclosed. The semiconductor device includes a substrate structure including a high side region, a low side region, a level shift region and an isolation region. The low side region is separated from the high side region. The level shift region and the isolation region are disposed between the low side region and the high side region. The level shift region is separated from the high side region by the isolation region. A doped isolation region, which is disposed in the isolation region, includes a first doped portion and a second doped portion adjacent to the first doped portion. The depth of the first doped portion is decreased linearly along a first direction from the isolation region to the level shift region. The depth of the second doped portion is decreased linearly along a second direction from the isolation region to the high side region.