SiC Semiconductor Element With Schottky Electrode for High-Speed Switching
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Solution Overview
Problem
Conventional semiconductor elements used in inverter circuits face challenges with high-speed switching and energy loss due to current concentration from counter electromotive voltage, leading to potential breakdown and reduced fabrication yield.
Innovation Solution
A semiconductor element with a schottky electrode and field effect transistors made from wide band-gap semiconductors, where the schottky electrode is strategically placed to form a schottky junction with the drift region, and a guard ring is used to manage electric field concentration, allowing for high-speed switching and reduced energy loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional semiconductor elements (IGBT, silicon MOSFET) are used for switching, then the device can operate with established technology, but the response speed is limited and switching loss increases
Solution Approach 1:
The patent changes the fundamental material parameter by using wide band-gap semiconductor (SiC) instead of conventional silicon, enabling higher switching speeds and reduced switching loss while maintaining device reliability
2Loss of energy
If higher switching speed is achieved using wide band-gap semiconductors, then switching loss is reduced, but current concentration from counter electromotive voltage causes breakdown and reduces fabrication yield
Solution Approach 1:
The schottky electrode acts as an intermediary element that provides a low-impedance path for counter electromotive voltage current, preventing current concentration and breakdown in the semiconductor substrate while enabling high-speed switching operations
3Reliability
If the schottky electrode area is increased to reduce current concentration, then breakdown resistance improves, but the area ratio of transistor cells to total element area decreases
Solution Approach 1:
The patent applies local quality by positioning the schottky electrode specifically at the periphery of the semiconductor element where current concentration occurs, rather than uniformly distributing it, thus maintaining high breakdown resistance while preserving transistor cell area ratio and fabrication yield
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 enables high-speed switching operations while reducing energy losses and improving resistance to current concentration, thereby preventing breakdown and enhancing the semiconductor element's reliability and efficiency in inverter circuits.
Implementation Method 1
a schottky electrode which is disposed on the upper surface of the drift region so as to form a schottky junction with the upper surface of the drift region
Implementation Method 2
a semiconductor layer made of a wide band-gap semiconductor
Implementation Method 3
a guard ring is used to manage electric field concentration, allowing for high-speed switching and reduced energy loss
Data Source
AI summary
A semiconductor element (20) of the present invention includes a plurality of field effect transistors (90) and a schottky electrode (9a), and the schottky electrode (9a) is formed along an outer periphery of a region where the plurality of field effect transistors (90) are formed.