Method of forming low turn on and high breakdown voltage lateral diode.
A hybrid Schottky and metal/high K dielectric/semiconductor contact to realize higher breakdown and low turn-on voltage for lateral diode based on wide bandgap semiconductors.
Practical realization of high breakdown fields in wide bandgap semiconductors such as GaN, SiC, typically requires the use of p-n junction, which require a turn-on voltage comparable to the bandgap of these semiconductors. For lower voltage applications, the forward or ON-state power loss due to higher turn-on voltage is typically much larger than the series resistance loss for PN rectifiers.
Mohammad Wahidur Rahman and his colleague at The Ohio State University have proposed a innovative solution to address this need. Schottky diodes are desirable due to their low turn voltage, but the maximum field achievable is limited by the metal/semiconductor barrier height. A solution to this problem is to use extreme permittivity dielectrics between the metal-semiconductor junctions. Such high-k/low-k hetero-junction reduce the field at the metal Schottky barrier, thus increasing the breakdown fields and voltages. Building on this concept we have developed a new method to achieve high breakdown while simultaneously achieving low turn-on voltage losses. This can lead to unprecedented low loss Schottky diodes for a range of semiconductor applications.
Mohammad Rahman is a graduate research associate at The Ohio State University in electrical engineering and is interested in semiconductor devices. Specifically, growth, fabrication and characterization of III-Nitride based High Electron Mobility Transistors. He is pursuing a Ph.D. in Electrical Engineering and will graduate in 2021, and he holds a bachelor's and master's in electrical engineering.