Guard Ring Semiconductor Layout for High Breakdown Voltage Density
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Solution Overview
Problem
Existing semiconductor devices face challenges in achieving high breakdown voltage while maintaining a small outer peripheral region, which limits current density and efficiency.
Innovation Solution
The semiconductor device incorporates a semiconductor substrate with an element region and an outer peripheral region featuring p-type guard rings, n-type spacing regions, and an n-type outer drift region, where at least one spacing region has a higher n-type impurity concentration, along with p-type field relief regions and n-type current path regions to manage electric fields and maintain high voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the outer peripheral region is made wide to achieve high breakdown voltage, then the breakdown voltage is improved, but the current density is reduced due to increased area
Solution Approach 1:
The patent applies local quality by creating high concentration n-type spacing regions with impurity concentrations of 1×10^17 to 1×10^19 atoms/cm³ specifically in the outer peripheral region between guard rings, while maintaining lower concentrations in other areas. This localized high concentration region suppresses high electric fields at the periphery, enabling high breakdown voltage without requiring a wide outer peripheral region, thus preserving current density in the element region.
2Productivity
If the outer peripheral region is narrowed to increase current density, then the current density is improved, but the breakdown voltage is reduced
Solution Approach 1:
The patent changes the impurity concentration parameter by forming high concentration n-type spacing regions with concentrations of 1×10^17 to 1×10^19 atoms/cm³ in the outer peripheral region. This parameter change suppresses high electric fields that would otherwise occur at the periphery, enabling the outer peripheral region to be narrowed without sacrificing breakdown voltage, thus increasing current density.
3Reliability
If guard rings are added to suppress electric fields, then the breakdown voltage is improved, but the device complexity increases
Solution Approach 1:
The patent merges the function of guard rings with the spacing regions by forming high concentration n-type spacing regions between the guard rings. This combination allows the spacing regions to actively participate in suppressing high electric fields alongside the guard rings, achieving high breakdown voltage with a more integrated and less complex structure.
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 allows for a high breakdown voltage to be achieved with a narrow outer peripheral region, reducing electrical resistance and suppressing high electric fields, thereby enhancing current density and device performance.
Implementation Method 1
At least one of the plurality of spacing regions is a high concentration spacing region having an n-type impurity concentration higher than that of the element drift region
Data Source
AI summary
A semiconductor device includes a semiconductor substrate having an element region and an outer peripheral region around the element region, and an upper electrode in contact with an upper surface the semiconductor substrate in the element region. The element region includes a p-type main region in contact with the upper electrode, and an n-type element drift region below the main region. The outer peripheral region includes a plurality of p-type guard rings disposed in multiple ring shapes surrounding the element region, a plurality of n-type spacing regions disposed between the guard rings, and an n-type outer drift region continuous with the element drift region and located below the guard rings and the spacing regions. At least one of the spacing regions is a high concentration spacing region having an n-type impurity concentration higher than that of the element drift region.