Superjunction Device Sidewall Doping for Voltage Blocking
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Solution Overview
Problem
The challenge in producing superjunction devices lies in precisely controlling the amount of doping atoms of different types in the drift region to optimize voltage blocking capability, which is currently difficult due to the need for balanced doping across various positions within the device.
Innovation Solution
A method involving the formation of semiconductor arrangements with trenches, where dopant atoms of different types are implanted into the sidewalls of these trenches, followed by annealing to activate them, allowing for precise control of doping concentrations and balanced distribution across the drift region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional doping methods are used to form drift region, then manufacturing process is simpler, but doping concentration control precision is insufficient
Solution Approach 1:
The drift region is divided into multiple trenches with different doping types (n-type and p-type) arranged in an alternating pattern. Each trench is independently doped through selective sidewall implantation, allowing precise control of doping concentrations in different regions. This segmentation enables independent optimization of each doped region's electrical properties while maintaining overall device performance.
Solution Approach 2:
Different doping concentrations and types are applied to different local regions (sidewalls of trenches) rather than uniform doping throughout the drift region. The sidewall implantation technique allows localized doping with precise control over dopant type, concentration, and depth in specific areas, creating non-uniform doping profiles that optimize voltage blocking and current conduction in different parts of the device.
2Reliability
If doping atoms are implanted to achieve balanced distribution, then voltage blocking capability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The trenches are formed with precisely controlled dimensions, depths, and spacing before doping is applied. This preliminary structuring establishes a geometric framework that guides subsequent doping processes, ensuring that dopant atoms are delivered to exact locations with controlled concentrations. The pre-formed trench structure enables predictable dopant distribution and facilitates achieving balanced doping profiles.
Solution Approach 2:
The alternating n-type and p-type trench structure creates inherent feedback mechanisms where the doping of one region influences and balances the adjacent regions. The complementary doping types in adjacent trenches provide self-regulating characteristics that help achieve balanced doping distributions, as the electrical fields and charge distributions in adjacent regions interact to stabilize the overall doping balance.
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 enables the precise control of doping concentrations, enhancing the voltage blocking capability of superjunction devices by ensuring balanced doping across the drift region, thereby improving the device's performance.
Implementation Method 1
implanting dopant atoms of at least one of a first type and a second type into at least one of a first sidewall and a second sidewall of each of the plurality of trenches of the semiconductor layer
Implementation Method 2
annealing the semiconductor arrangement to simultaneously activate the first type dopant atoms and the second type dopant atoms
Data Source
AI summary
Forming a semiconductor arrangement includes providing a first semiconductor layer having a first surface, forming a first plurality of trenches in the first surface of the first semiconductor layer, each of the trenches in the first plurality having first and second sidewalls that extend from the first surface to a bottom of the respective trench, implanting first type dopant atoms into the first and second sidewalls of each of the trenches in the first plurality, implanting second type dopant atoms into the first and second sidewalls of each of the trenches in the first plurality, and annealing the semiconductor arrangement to simultaneously activate the first type dopant atoms and the second type dopant atoms.