L-Shaped Ring Schottky Diode for Tunable Blocking Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Schottky diodes in high voltage applications face challenges in achieving high blocking voltage while minimizing leakage current, as they often have higher leakage currents compared to P-N junction diodes.
Innovation Solution
The design incorporates an L-shaped ring and a buried layer with an open region vertically aligned with the anode, along with additional p-type rings and field plates, allowing for adjustable dimensions and doping profiles to control and increase the blocking voltage of the Schottky diode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If Schottky diode structure is used for high voltage applications, then switching speed and forward voltage drop are improved, but leakage current increases
Solution Approach 1:
The patent applies local quality by creating a non-uniform doping profile with an L-shaped ring structure that concentrates dopants in specific regions. The ring has varying doping concentrations - heavier doping at certain locations and lighter doping at others - to locally control electric field distribution and carrier behavior, thereby reducing leakage current in critical areas while preserving fast switching characteristics throughout the diode structure.
Solution Approach 2:
The patent employs parameter changes by systematically varying doping concentrations, layer thicknesses, and geometric dimensions of the L-shaped ring structure. By adjusting these parameters, the electric field distribution and depletion region characteristics are optimized to reduce leakage current while maintaining the low forward voltage drop and fast switching speed inherent to Schottky diodes.
2Use of energy by moving object
If conventional Schottky diode structure is used, then forward voltage drop is reduced, but blocking voltage capability is insufficient
Solution Approach 1:
The patent applies segmentation by dividing the diode structure into distinct functional layers including the L-shaped ring, substrate, and epitaxial layer. Each segment serves a specific purpose: the L-shaped ring provides field control and leakage reduction, the substrate provides mechanical support and initial doping, and the epitaxial layer provides the main depletion region. This segmentation allows optimization of each part for its specific function while achieving overall high blocking voltage capability.
Solution Approach 2:
The patent uses composite materials by combining differently doped semiconductor regions in a multi-layer structure. The L-shaped ring with its specific doping profile, when integrated with the substrate and epitaxial layer, creates a composite structure that leverages the advantageous properties of each region to achieve both low forward voltage drop and high blocking voltage capability simultaneously.
3Reliability
If doping concentration is increased to improve blocking voltage, then leakage current increases
Solution Approach 1:
The patent applies local quality by creating a non-uniform doping profile with an L-shaped ring structure that concentrates dopants in specific regions. The ring has varying doping concentrations - heavier doping at certain locations and lighter doping at others - to locally control electric field distribution and carrier behavior, thereby reducing leakage current in critical areas while preserving fast switching characteristics throughout the diode structure.
Solution Approach 2:
The L-shaped ring structure introduces curvature into the doping profile, creating a non-linear electric field distribution. This curved doping profile helps to smooth out electric field peaks that would otherwise occur at sharp corners or interfaces, thereby reducing breakdown voltage enhancement while controlling leakage current pathways through the device.
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 configuration achieves a breakdown voltage of 110 volts or greater, enhancing the diode's blocking capability and suitability for various high-voltage applications, including protection of power MOSFETs and as a Transient Voltage Suppressor.
Implementation Method 1
Schottky diodes can have faster switching speed and lower forward voltage drop as compared to other high voltage switching solutions
Implementation Method 2
a substrate having a first type dopant, a buried layer within the substrate and having a second type dopant, an epitaxial layer above the buried layer and having the second type dopant, a plurality of rings within the epitaxial layer and having the first type dopant
Data Source
AI summary
A Schottky diode includes a substrate having a first type dopant, a buried layer within the substrate and having a second type dopant, an epitaxial layer above the buried layer and having the second type dopant, a plurality of rings within the epitaxial layer and having the first type dopant, wherein the plurality of rings comprises an L-shaped ring, a shallow trench isolation (STI) layer at the top region of the epitaxial layer, an anode, a cathode spaced from the anode by the STI layer, and wherein the buried layer has an open region substantially vertically aligned with the anode.