Structured Current Spread Region in Power Semiconductors
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Solution Overview
Problem
Existing power semiconductor devices face challenges in achieving low on-state resistance and high breakdown voltage, which are crucial for minimizing losses and preventing damage during operation, especially at higher voltages.
Innovation Solution
A semiconductor device with a structured current spread portion and a manufacturing method that includes a drift portion of a first conductivity type, a current spread portion with higher doping concentration, and first portions of the same conductivity type, arranged in a specific plane on the drift portion, which reduces on-state resistance and increases breakdown voltage by spreading current and reducing electric field strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the doping concentration in the drift region is increased to reduce on-state resistance, then the on-state resistance decreases, but the breakdown voltage decreases
Solution Approach 1:
The patent applies local quality by creating a structured current spread region with spatially varying doping concentrations. The drift region contains multiple zones: a first region with lower doping concentration (1×10^15 to 1×10^16 atoms/cm³) for high breakdown voltage, and a second region with higher doping concentration (1×10^16 to 1×10^17 atoms/cm³) for low on-state resistance. This non-uniform doping distribution allows each region to optimize its local function, resolving the contradiction between low on-state resistance and high breakdown voltage.
Solution Approach 2:
The drift region is segmented into distinct doped regions with different doping concentrations. The current spread region is divided into a first region and a second region, each with specific doping levels. This segmentation allows the device to simultaneously achieve high breakdown voltage in the first region and low on-state resistance in the second region, resolving the fundamental trade-off between these two parameters.
2Device complexity
If a uniform doping structure is used, then the device structure is simple, but the current distribution is concentrated leading to higher on-state resistance and lower breakdown voltage
Solution Approach 1:
Instead of uniform doping, the patent implements local quality variations through a structured current spread region with different doping concentrations in different spatial locations. The first region has lower doping (1×10^15 to 1×10^16 atoms/cm³) while the second region has higher doping (1×10^16 to 1×10^17 atoms/cm³), creating optimized local electrical properties that reduce overall on-state resistance and improve current distribution.
Solution Approach 2:
The patent changes the doping concentration parameter across different regions of the drift region. By varying the doping concentration from 1×10^15 to 1×10^17 atoms/cm³ across different zones, the device achieves improved current spreading and reduced on-state resistance while maintaining manufacturability through controlled doping processes.
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 solution effectively decreases on-state resistance and increases breakdown voltage, improving the overall performance and reliability of power semiconductor devices by optimizing current distribution and electric field management.
Implementation Method 1
the doping concentration of the current spread portion is higher than the doping concentrations of the drift portion and of the first portions
Implementation Method 2
the first portions of the drift region reduce the electric field strength in certain areas of the semiconductor body near the body regions
Data Source
AI summary
A semiconductor device with structured current spread region and method is disclosed. One embodiment provides a drift portion of a first conductivity type, a current spread portion of the first conductivity type and first portions of the first conductivity type. The current spread portion and the first portions are arranged in a first plane on the drift portion, wherein the current spread portion surrounds at least partially the first portions. The semiconductor body further includes spaced apart body regions of a second conductivity type which are arranged on the current spread portion. Further, the doping concentration of the current spread portion is higher than the doping concentrations of the drift portion and of the first portions.