MPS Diode Well Spacing Layout for Uniform Surge Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
MPS diodes face challenges with high on-state voltage drop and limited forward surge current capability due to non-uniform current conduction, leading to local heating and reduced long-term operation, primarily caused by varying spacing between wells which affects voltage distribution across PN junctions.
Innovation Solution
The MPS diode design features an increasing spacing between adjacent wells from the center to the edge of the active area, ensuring uniform current flow and dopant concentration profiles to maintain Schottky current, thereby improving on-state voltage and forward surge current capability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If uniform spacing between wells is used, then manufacturing is simple, but current conduction is non-uniform causing high on-state voltage drop
Solution Approach 1:
The patent applies local quality by varying the spacing between adjacent wells in different regions of the active area. Specifically, the spacing is made smaller in regions where higher current density is expected and larger in regions where lower current density occurs, thereby optimizing current distribution locally throughout the device structure.
2Device complexity
If uniform spacing between wells is used, then device structure is simple, but forward surge current capability is limited due to local heating
Solution Approach 1:
The patent applies local quality by varying the spacing between adjacent wells in different regions of the active area. Specifically, the spacing is made smaller in regions where higher current density is expected and larger in regions where lower current density occurs, thereby optimizing current distribution locally throughout the device structure.
3Productivity
If smaller spacing between wells is used, then more Schottky contacts are formed improving current conduction, but voltage distribution becomes non-uniform across PN junctions
Solution Approach 1:
The patent applies local quality by varying the spacing between adjacent wells in different regions of the active area. Specifically, the spacing is made smaller in regions where higher current density is expected and larger in regions where lower current density occurs, thereby optimizing current distribution locally throughout the device structure.
Solution Approach 2:
The patent applies parameter changes by systematically varying the spacing parameter between adjacent wells across different regions of the active area. This spatial variation in the spacing parameter enables uniform voltage distribution across all PN junctions while maintaining efficient current conduction through optimized Schottky contact formation.
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 design enhances current uniformity, reducing voltage drops and increasing the forward surge current capability, thus improving the power handling and longevity of the MPS diode.
Implementation Method 1
a plurality of wells of a second conductivity type different from the first conductivity type, the plurality of wells being mutually spaced apart, each well forming a respective PN-junction with the drift region
Implementation Method 2
the metal layer assembly forming a plurality of Schottky contacts together with the drift region
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Aspects of the present disclosure generally relate to an MPS diode and a manufacturing method therefor. The MPS diode comprises a semiconductor body including an active area, wherein the active area comprises a drift region of a first conductivity type, and a plurality of wells of a second conductivity type different from the first conductivity type, the plurality of wells being mutually spaced apart, each well forming a respective PN-junction with the drift region. The MPS diode further comprises a metal layer assembly arranged on a surface of the semiconductor body and comprising at least one metal layer, the metal layer assembly forming a plurality of Schottky contacts together with the drift region and a plurality of respective Ohmic contacts with the plurality of wells. A spacing between adjacently arranged wells increases in an outward direction from a center of the active area.