Semiconductor Edge Terminal Guard Ring High Concentration Region
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Solution Overview
Problem
In semiconductor devices, particularly those with IGBTs, the electric field can become intensified near the bottom portion of the guard ring, leading to potential breakdown issues and reduced reliability.
Innovation Solution
The semiconductor device incorporates an edge terminal structure with guard rings of a second conductivity type, featuring a high concentration region of the first conductivity type between guard rings, which extends from a position shallower than the guard rings' lower ends to a position deeper than them, and includes a separate lower part with a different dopant, such as hydrogen, to mitigate electric field concentrations and improve breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a P type guard ring is provided in an outer peripheral part of an N type semiconductor substrate, then the semiconductor device structure is formed, but the electric field is intensified in the vicinity of a bottom portion of the guard ring
Solution Approach 1:
The patent introduces a high concentration region with a doping concentration higher than the drift region between adjacent guard rings. This creates a localized area with different electrical properties (higher carrier concentration) that specifically addresses the electric field concentration problem at the guard ring bottom portion, while maintaining the overall guard ring structure and its functions.
Solution Approach 2:
The patent changes the doping concentration parameter by introducing a high concentration region with doping concentration higher than the drift region. This parameter change modifies the electrical characteristics of the semiconductor substrate in the critical area between guard rings, thereby reducing electric field intensity and preventing premature breakdown.
2Reliability
If guard rings are provided to protect the semiconductor device, then the device structure is established, but electric field intensification occurs at the bottom portion of the guard ring leading to potential breakdown
Solution Approach 1:
The high concentration region acts as an intermediary structure between the guard rings and the drift region. It serves as a transition zone that mediates the electric field distribution, preventing the direct concentration of electric field lines at the guard ring bottom portion while maintaining the protective function of the guard rings.
Solution Approach 2:
By creating a localized high concentration region with specific doping characteristics between the guard rings, the patent introduces a zone with tailored electrical properties that specifically addresses the electric field intensification problem without altering the overall guard ring protection mechanism.
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 effectively reduces electric field concentrations and enhances the breakdown voltage of the semiconductor device by distributing the electric field more evenly and preventing avalanche breakdown at lower voltages.
Implementation Method 1
An electric field may be intensified in the vicinity of a bottom portion of the guard ring in some cases
Implementation Method 2
preventing avalanche breakdown at lower voltages
Data Source
AI summary
A semiconductor device includes a semiconductor substrate having a drift region, and an edge terminal structure portion provided between the active region and an end portion of the semiconductor substrate on an upper surface of the semiconductor substrate. The edge terminal structure portion includes a plurality of guard rings of a second conductivity type which are in contact with the upper surface, and a high concentration region of the first conductivity type which has a higher doping concentration than the drift region and is provided, between adjacent two of the guard rings, from a position shallower than lower ends of the guard rings to a position deeper than the lower ends of the guard rings. Each of the guard rings has a region that is not covered by the high concentration region as viewed from a lower surface side.