Semiconductor Latch-Up Suppression via Localized High-Concentration Regions
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Solution Overview
Problem
Semiconductor devices face challenges in suppressing latch-up phenomena without affecting the threshold voltage and other characteristics, as existing methods either compromise latch-up suppression or optimize device characteristics at the expense of other parameters.
Innovation Solution
A semiconductor device design that includes a latch-up suppression region with higher impurity concentration than the base region, positioned within the base region and connected to a conductive layer, and a dummy trench with a break, which helps in reducing the resistance of the base region and preventing charge accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a P+ layer is formed in the base region to suppress latch-up, then latch-up suppression is improved, but the threshold voltage and other device characteristics are affected
Solution Approach 1:
The invention introduces a dedicated latch-up suppression region with high impurity concentration specifically in areas where latch-up occurs, rather than uniformly increasing impurity concentration throughout the base region. This localized approach suppresses latch-up while preserving the threshold voltage and other characteristics in the main device operation areas.
Solution Approach 2:
The base region is divided into functionally distinct areas: the main base region for device operation and the separate latch-up suppression region for reliability. This segmentation allows independent optimization of each region's properties without mutual interference.
2Reliability
If the impurity concentration of the base layer is increased to decrease base region resistance, then latch-up suppression is improved, but the threshold voltage and other characteristics are affected
Solution Approach 1:
The invention applies high impurity concentration locally in the latch-up suppression region to decrease resistance and suppress latch-up, while maintaining the original base layer impurity concentration in the main device regions to preserve optimized characteristics.
3Reliability
If a p-type high-concentration region is formed in the body region to suppress latch-up, then latch-up suppression is improved, but the trade-off between latch-up suppression and characteristic optimization exists
Solution Approach 1:
The invention segments the semiconductor structure into distinct functional regions with different impurity profiles: the main body region for device operation and the separate latch-up suppression region. This simplifies the overall design by allowing independent optimization of each region without complex multi-layer impurity profiles.
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 design effectively suppresses latch-up without impacting the threshold voltage or other characteristics, improving the reverse bias safe operating area (RBSOA) and reducing the resistance of the base region, thereby enhancing the device's operational safety and efficiency.
Implementation Method 1
a latch-up suppression region (34) of the second conductivity type which is formed within the base region (32), in contact with the electrically conductive layer (31), and higher in impurity concentration than the base region (32)
Implementation Method 2
The distance between the gate insulation film and the latch-up suppression region is not less than the maximum width of a depletion layer that is formed in the base layer by the trench gate
Data Source
AI summary
A semiconductor device includes a substrate of a first conductivity type, a base region of a second conductivity type, a source region of the first conductivity type, a collector region of the second conductivity type, a trench gate, which is formed in a trench via a gate insulation film, an electrically conductive layer, which is formed within a contact trench that is formed through the source region, a source electrode, which is in contact with the electrically conductive layer and the source region, and a latch-up suppression region of the second conductivity type, which is formed within the base region, in contact with the electrically conductive layer, and higher in impurity concentration than the base region. The distance between the gate insulation film and the latch-up suppression region is not less than the maximum width of a depletion layer that is formed in the base layer by the trench gate.