Electrically detected magnetic resonance in SiC MOSFETs utilizing multiple techniques

Conference Dates

May 21-25, 2017


Silicon carbide based MOS devices have great promise in high power and high temperature applications. Unfortunately, the interface region between the silicon carbide and the silicon dioxide in these devices is far from perfect. The imperfections involve point defects in the interface and near interface region between the silicon carbide and silicon dioxide. In large part, it is the presence of these defects which leads to disappointingly low effective channel mobilities and sometimes significant threshold voltage instabilities. In this study we show that electrically detected magnetic resonance (EDMR) techniques can provide substantial physical insight into the physical and chemical nature of these performance limiting imperfections. The EDMR techniques are sufficiently sensitive so that they can be made on fully functional fully processed devices. EDMR measurements are based on electron paramagnetic resonance. EPR measurements have unrivaled analytical power in determining the physical and chemical nature of point defects such as trapping centers in semiconductors and insulators. EDMR measurements have additional advantages in that they are exclusively sensitive to only those defects in some way involved in device performance. We show in this work that the EDMR measurements can also provide some information about defect energy levels and (admittedly crude) information about the physical location of the defects within the devices under study. We will present EDMR measurements utilizing spin dependent recombination (SDR) as well as spin dependent charge pumping (SDCP). Our measurements also utilize a wide variety of magnetic field strength and frequency combinations. Our lowest field frequency combinations are approximately 30 Gauss and approximately 80 MHZ. Our highest field/ frequency measurements are at about 5600 Gauss and a frequency of 16 GHz. To the best of our knowledge, such a combination of EDMR techniques has not previously been applied to any solid state device systems. As will be discussed in our presentation, It is this combination of multiple techniques which allows EDMR to achieve a very high analytical power. As will be discussed on our presentation, the approach we have utilized in our SiC MOSFET study could be applied to many other solid state device systems of interest to the attendees of this meeting

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