Semiconductor Guard Ring Layout Using Shared Partial Doping
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Solution Overview
Problem
The existing process for forming power devices is inefficient due to the need for additional photomask and doping processes for the guard ring, increasing manufacturing steps and costs, and the electric field intensity in edge cylindrical or corner spherical regions of the main junction is higher than in planar junctions, leading to reduced breakdown voltage.
Innovation Solution
A semiconductor structure and method where a guard ring is doped with a first dopant ion of a different conductivity type than the power device, using a partial doping process that eliminates the need for additional photomask and doping processes, and a second dopant ion is used to create a completely depleted layer, reducing electric field intensity and improving breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional photomask and doping processes are used to form the guard ring, then the breakdown voltage is improved, but the process complexity and manufacturing cost increase
Solution Approach 1:
The patent merges the guard ring formation process with the power device doping process by using a single photomask and doping step to simultaneously create both structures. The photomask is designed with transparent regions corresponding to the guard ring positions, allowing the doping ions to form both the power device regions and the guard rings in one operation, thereby reducing process complexity while maintaining the breakdown voltage improvement.
2Reliability
If additional photomask and doping processes are used to form the guard ring, then the breakdown voltage is improved, but the manufacturing cost increases
Solution Approach 1:
The patent combines multiple manufacturing steps into a single operation. By designing the photomask to include transparent regions that define the guard ring areas, the doping process simultaneously creates both the power device regions and the guard rings. This eliminates the need for separate photomask fabrication and doping steps, directly reducing manufacturing cost while achieving the desired breakdown voltage improvement.
3Reliability
If the guard ring is formed separately from the power device, then the electric field distribution is optimized, but the process time increases
Solution Approach 1:
The patent implements simultaneous formation of the power device and guard ring structures through a single doping process. The photomask is configured with transparent regions that allow doping ions to reach the guard ring areas while other regions define the power device structures. This parallel formation approach maintains optimized electric field distribution through proper guard ring positioning while reducing total process time by eliminating sequential operations.
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 approach reduces process steps and costs by integrating the guard ring formation into the power device doping process, while the completely depleted layer formed by the guard ring effectively lowers electric field intensity, enhancing breakdown voltage.
Implementation Method 1
The doping process includes an ion implantation doping process or an epitaxial growth doping process
Implementation Method 2
the guard ring is doped with a first dopant ion that is formed by a partial doping process used in forming the power device
Data Source
AI summary
The present disclosure provides a semiconductor structure and a method for forming the semiconductor structure. The method includes: providing a substrate including a device region and a guard ring region surrounding the device region; and forming a power device in the device region and forming a guard ring in the guard ring region, wherein the guard ring is doped with a first dopant ion that is formed by a partial doping process used in a formation of the power device, and a conductivity type of the first dopant ion in the guard ring is different from a device type of the power device. Since the guard ring is formed by the necessary doping process used in forming the power device, additional photomask process and doping process for forming the guard ring is omitted, effectively reducing process steps and process costs.