Schottky Diode High Breakdown Voltage Low Forward Resistance
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Solution Overview
Problem
The semiconductor industry faces challenges in integrating Schottky diodes onto semiconductor substrates with high breakdown voltage and low forward resistance, as existing methods struggle to achieve both high breakdown voltage (e.g., 500 V or greater) and low forward resistance (e.g., less than 100 ohms) simultaneously.
Innovation Solution
A Schottky diode structure is formed on a semiconductor substrate with specific doping concentrations and region configurations, including N-type and P-type doped regions, guard rings, and MOS gates, which enhance breakdown voltage and reduce forward resistance by managing electric fields and current flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a Schottky diode is integrated onto a semiconductor substrate, then the diode can be combined with other semiconductor components, but achieving both high breakdown voltage (500 V or greater) and low forward resistance (less than 100 ohms) simultaneously becomes extremely difficult
Solution Approach 1:
The patent applies local quality by creating distinct doped regions with different properties: lightly-doped drift regions for high breakdown voltage, heavily-doped contact regions for low forward resistance, and guard rings with specific doping concentrations at strategic locations. Each region is optimized for its specific function, allowing the diode to achieve both high breakdown voltage and low forward resistance simultaneously while being integrable with other components on the substrate.
2Reliability
If the Schottky diode structure is optimized for high breakdown voltage, then the breakdown voltage increases, but the forward resistance tends to increase as well
Solution Approach 1:
The patent segments the diode structure into multiple functional regions: a lightly-doped drift region extending from the Schottky interface to provide high breakdown voltage, heavily-doped contact regions at the ends to provide low forward resistance, and guard rings with intermediate doping. This segmentation allows each region to be optimized for its specific function, achieving both high breakdown voltage and low forward resistance without compromise.
Solution Approach 2:
The patent utilizes parameter changes by varying the doping concentration across different regions of the diode structure. The drift region has low doping concentration (10^14 to 10^16 atoms/cm³) for high breakdown voltage, while contact regions have high doping concentration (10^18 to 10^20 atoms/cm³) for low forward resistance. This gradient in doping parameters enables simultaneous optimization of both breakdown voltage and forward resistance.
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 proposed structure achieves high breakdown voltage and low forward resistance, enabling efficient integration of Schottky diodes with other semiconductor components, while maintaining fast switching times and minimizing reverse leakage current.
Implementation Method 1
forming an anode conductor to a surface of the drift region to form a Schottky junction along an interface of the anode conductor and the drift region
Implementation Method 2
N-type doped regions generally are formed to overlap respective first and second portions of the drift region. A portion of the drift region extends between the N-type doped regions
Data Source
AI summary
In one embodiment, a Schottky diode is formed on a semiconductor substrate with other semiconductor devices and is also formed with a high breakdown voltage and a low forward resistance.