Trench Gate Semiconductor Device With Field Plate Electrode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power semiconductor devices face a trade-off between breakdown voltage and on-resistance, and existing designs fail to maintain uniform electric field distribution in termination regions, leading to decreased breakdown voltage.
Innovation Solution
A semiconductor device with a trench gate and field plate electrode, featuring a specific impurity concentration distribution and trench structure that extends from the active region to the termination region, ensuring uniform electric field distribution and improved breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a trench gate structure with field plate electrode is used, then on-resistance is reduced, but breakdown voltage decreases due to non-uniform electric field distribution in termination region
Solution Approach 1:
The patent applies local quality by creating different impurity concentration distributions in different regions: the active region has a first impurity concentration distribution optimized for low on-resistance, while the termination region has a second impurity concentration distribution (higher than the first) specifically designed to achieve uniform electric field distribution and maintain high breakdown voltage. This regional differentiation resolves the contradiction between low on-resistance and high breakdown voltage.
Solution Approach 2:
The patent changes the impurity concentration parameter across different regions and depths. By increasing the impurity concentration in the termination region compared to the active region, and by creating specific depth-dependent concentration profiles, the electric field distribution is controlled to be uniform in the termination region while maintaining the required electrical characteristics in the active region, thereby resolving the breakdown voltage issue.
2Ease of manufacture
If constant impurity concentration is used in termination region, then manufacturing is simplified, but electric field distribution becomes non-uniform and breakdown voltage decreases
Solution Approach 1:
The patent implements local quality by specifying that the termination region has a different impurity concentration distribution than the active region. The second impurity concentration distribution in the termination region is deliberately designed to be higher and create uniform electric field distribution, while the active region maintains its optimized profile. This localized differentiation maintains manufacturability while achieving the required electrical performance.
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 solution enhances the breakdown voltage in both the active and termination regions, reducing on-resistance and maintaining equivalent electric field distribution across the device.
Implementation Method 1
the electric field distribution of the drift region is more uniform, and the trade-off between the breakdown voltage and on-resistance of an active region is improved
Implementation Method 2
a power MOS transistor having a field plate electrode buried in a trench and having a distribution of an impurity concentration in a direction from the bottom portion side to the upper side of the trench
Data Source
AI summary
A semiconductor device includes a semiconductor layer of a first conductivity type having first and second surfaces and an impurity concentration distribution in a first direction from the second surface to the first surface, a first semiconductor region of a second conductivity between the semiconductor layer and the first surface, a second semiconductor region of a first conductivity type between the first semiconductor region and the first surface side, a first trench extending from the first surface into the semiconductor layer, a first electrode located in the first trench over a first insulating film and spaced from the first semiconductor region by a first insulating film, a second electrode located in the first trench over a second insulating film, a second trench extending from the first surface into the semiconductor layer and surrounding the first trench, and a third electrode located in the second trench over a third insulating film.