Trench Semiconductor Layout for IGBT Latch-Up Suppression
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Solution Overview
Problem
Conventional semiconductor devices, such as IGBTs, face challenges in suppressing latch-up phenomena during turn-off operations due to high resistance in the movement path of electron holes, leading to increased voltage and potential breakdown.
Innovation Solution
Incorporating a P+ type connecting region between adjacent contact regions in the mesa portion of the semiconductor device, which connects two contact regions of high doping concentration, reducing resistance and suppressing latch-up by facilitating electron hole movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional semiconductor device structure is used, then device simplicity is maintained, but resistance in electron hole movement path is high causing latch-up phenomena
Solution Approach 1:
The contact region is segmented into multiple contact regions (first contact region and second contact region) with a connecting region positioned between them. This segmentation allows the connecting region to specifically facilitate electron hole movement between the contact regions, reducing resistance and suppressing latch-up phenomena without requiring complex overall device restructuring.
Solution Approach 2:
A connecting region with third doping concentration is locally introduced between the first and second contact regions. This local quality change creates a low-resistance path specifically where needed for electron hole movement, while other parts of the device maintain their original structure. The connecting region's doping concentration is optimized to be higher than the drift region but lower than the contact regions, providing targeted resistance reduction.
2Reliability
If high doping concentration is used in contact regions, then contact resistance is reduced, but resistance in electron hole movement path between contact regions remains high
Solution Approach 1:
The invention introduces a connecting region with a specific doping concentration parameter that is optimized for electron hole movement. The third doping concentration in the connecting region is set to be higher than the drift region's doping concentration but lower than the contact regions' doping concentration. This parameter optimization creates an effective electron hole movement path without requiring extreme doping concentrations that would be difficult to manufacture.
3Reliability
If simple contact region structure is used, then manufacturing is easier, but voltage increases during turn-off causing breakdown
Solution Approach 1:
The connecting region acts as an intermediary structure between the first and second contact regions. It provides a dedicated low-resistance path for electron hole movement during turn-off operations, preventing voltage buildup that would lead to breakdown. The connecting region mediates the electrical interaction between contact regions, enabling stable voltage characteristics without requiring complex contact region restructuring.
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 implementation of a P+ type connecting region effectively reduces resistance in the electron hole movement path, thereby suppressing latch-up and maintaining stable device operation.
Implementation Method 1
Incorporating a P+ type connecting region between adjacent contact regions in the mesa portion of the semiconductor device, which connects two contact regions of high doping concentration, reducing resistance and suppressing latch-up by facilitating electron hole movement
Data Source
AI summary
Provided is a semiconductor device including a drift region, a base region, two trench portions and a mesa portion, wherein at least one of the two trench portions is a gate trench portion, the mesa portion includes: a first conductivity type emitter region provided to be exposed on an upper surface of the mesa portion; a second conductivity type contact region provided to be exposed on the upper surface of the mesa portion alternately with the emitter region in an extending direction; and a second conductivity type connecting region with a higher doping concentration than the base region, wherein the connecting region is provided to overlap with the emitter region in a top view, is arranged apart from the gate trench portion, is arranged below the upper surface of the mesa portion, and connects two of the contact regions sandwiching the emitter region in the extending direction.