Formation processes of Ge3N4 films by radical nitridation and their electrical properties

Formation processes of Ge3N4 by radical nitridation and electrical properties of Pr-oxide/Ge3N4/Ge structure were investigated. Stoichiometric Ge3N4 is successfully formed by the radical nitridation at temperatures from 50 to 600 °C. Change in the nitridation temperature dependence of the saturated thickness of the Ge3N4 suggests different dominant diffusion species. Leakage current density through the Ge3N4 is minimized at a nitridation temperature of 300 °C. The XPS analyses of the Pr-oxide/Ge3N4/Ge suggest decomposition of Ge3N4 during atomic layer deposition of the Pr-oxide and formation of Pr-oxynitride at the Pr-oxide/Ge interface. An interface state density in the Al/Pr-oxide/Ge3N4/Ge capacitor is drastically reduced by forming gas annealing.