Semiconductor Device Trench Gate Impurity Segmentation
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Solution Overview
Problem
Semiconductor devices with trench gate structures face reduced avalanche resistance due to current concentration during the turn-off period at high impurity concentration regions that protrude into the drift region, leading to lower breakdown voltage.
Innovation Solution
The semiconductor device incorporates a control electrode with specific regions of varying p-type impurity concentrations and structures, including a third region that mitigates electric field concentrations and avalanche currents by positioning these regions between the gate electrode and the semiconductor body, and using insulating films to manage electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a high impurity concentration region protrudes into the drift region at the gate end, then the electric field concentration is mitigated and static breakdown voltage is enlarged, but the avalanche resistance is lowered due to current concentration during turn-off period
Solution Approach 1:
The patent applies local quality by creating distinct impurity concentration zones within the drift region. Specifically, a first impurity concentration region with higher concentration and a second impurity concentration region with lower concentration are formed at different locations. The higher concentration region is positioned to mitigate electric field concentration at the gate end, while the lower concentration region is positioned to reduce current concentration during turn-off, thereby simultaneously improving both breakdown voltage and avalanche resistance through spatially differentiated material properties.
2Object-affected harmful factors
If the gate end is positioned in the high impurity concentration region, then electric field concentration is reduced, but current concentration occurs during turn-off period
Solution Approach 1:
The patent segments the drift region into multiple functional zones with different impurity concentrations. The drift region is divided into a first impurity concentration region and a second impurity concentration region, each serving different purposes. The first region handles electric field management at the gate end, while the second region manages current distribution during turn-off. This segmentation allows independent optimization of each harmful factor without compromising the other.
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 enhances the static breakdown voltage and improves avalanche resistance during the turn-off period by reducing electric field concentrations and controlling current flow effectively.
Implementation Method 1
The control electrode is electrically insulated from the semiconductor body via a first insulating film
Implementation Method 2
The third semiconductor layer is selectively provided between the first region of the second semiconductor layer and the first electrode... mitigates electric field concentrations and avalanche currents
Data Source
AI summary
A semiconductor device includes a semiconductor body, a first electrode, a control electrode and a control interconnection electrically connected to the control electrode. The first electrode, the control electrode, and the control interconnection are provided on a front surface side of the semiconductor body. The control electrode is shaped as one body in a trench. The control electrode includes a first portion, a second portion, a first end portion and a second end portion that are arranged in a direction along the front surface of the semiconductor body. The first and second portions are positioned between the first and second end portions. The first portion is positioned between the first electrode and the semiconductor body, and the second portion is positioned between the control interconnection and the semiconductor body. The control interconnection crosses the second portion of the control electrode, and is electrically connected thereto.