Schottky Diode Field Plate Segmentation
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Solution Overview
Problem
High-voltage Schottky barrier diodes require effective limitation of electric fields at the interface between semiconductor material and metal to achieve higher breakdown voltages, which existing technologies struggle to manage efficiently.
Innovation Solution
The Schottky barrier diode design incorporates a semiconductor body with doped regions of opposite conductivity types, a silicide layer forming an interface, an insulating region, and a field plate to create a reduced surface field condition, ensuring efficient voltage blocking and minimizing device size by maintaining a short cathode-anode length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If highly doped regions are added at the surface to limit electric field and increase breakdown voltage, then blocking voltage capability is improved, but device structure and manufacturing process become more complex
Solution Approach 1:
The further doped region is divided into two distinct subregions: a first subregion with lower doping concentration and a second subregion with higher doping concentration. This segmentation allows each subregion to perform specific functions - the first subregion provides reduced surface field condition while the second subregion provides voltage blocking capability - thereby achieving high blocking voltage without requiring overly complex structures
Solution Approach 2:
Different doping concentrations are applied to different spatial locations (subregions) of the further doped region. The first subregion has lower doping concentration to reduce surface field, while the second subregion has higher doping concentration to block high voltage. This local quality variation enables the single component to simultaneously address multiple requirements
2Reliability
If highly doped regions are added to push electric potential towards cathode, then breakdown voltage is improved, but manufacturing process requires additional masks and implantation steps
Solution Approach 1:
The further doped region is segmented into first and second subregions with different doping concentrations, enabling each subregion to be formed by separate implantation processes with appropriate masking, thus achieving the desired electric field distribution and voltage blocking capability through structured manufacturing steps
3Reliability
If the diode structure is extended to include additional doped regions and contacts, then voltage blocking capability is improved, but cathode-anode length increases
Solution Approach 1:
The patent introduces a vertical dimension by adding a field plate above the first subregion, separated by an insulating region. This three-dimensional arrangement allows the field plate to provide additional voltage blocking capability without significantly extending the horizontal cathode-anode length, as the blocking function is achieved in the vertical direction through the insulating region and field plate 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 design achieves a high blocking voltage capability while maintaining a low on-resistance in forward bias, effectively protecting the interface against high electric fields and ensuring efficient current conduction.
Implementation Method 1
A Schottky barrier diode comprises an interface between metal and moderately doped semiconductor material, a so-called Schottky contact, which conducts primarily in one direction
Implementation Method 2
a field plate on the insulating region, the insulating region separating the field plate from the further doped region, and the electric contact electrically connecting the doped region with the field plate
Implementation Method 3
The purpose of the highly doped regions is to build up a space charge region below the interface, in order to push the electric potential towards the cathode
Data Source
AI summary
The Schottky barrier diode comprises a semiconductor body with a main surface, a doped region and a further doped region of the semiconductor body, which extend to the main surface, the doped region and the further doped region having opposite types of electric conductivity, a subregion and a further subregion of the further doped region, the subregions being contiguous with one another, the further subregion comprising a higher doping concentration than the subregion, a silicide layer on the main surface, the silicide layer forming an interface with the doped region, an electric contact on the doped region, and a further electric contact electrically connecting the further doped region with the silicide layer.