Electrically Detected Magnetic Resonance (EDMR) Studies of SiC-SiO<sub>2</sub> Interfaces

Abstract

We discuss the results of electrically detected magnetic resonance (EDMR) spectroscopy on SiC-SiO2 interfaces interacting with hydrogen and nitrogen. Using EDMR, three types of 4H-SiC MOSFETs, which were prepared by dry oxidation (“Dry” sample), post hydrogen anneal (“Hydrogen” sample), and post nitridation anneal (“Nitrogen” sample), were examined in the temperature range of 4–300 K. These samples revealed several different results from the earlier ESR (electron spin resonance) and EDMR studies on SiC-SiO2 interfaces. The most significant finding was the high-density doping of nitrogen into the channel region after the post nitridation anneal. The incorporated nitrogen donors were observed as the “Nh” EDMR signal at 4–20 K. Roles of these nitrogen donors are discussed in correlation with the electrical properties of SiC MOSFETs.