Al-oxynitrides as a buffer layer for Pr2O3/SiC interfaces

We elaborate the possibility of combining high-k dielectrics with wide band gap semiconductors, i.e. Pr2O3 on SiC. The thermal stability of interfacial aluminum oxynitride (AlON) layers between Pr-oxide and SiC has been investigated by synchrotron radiation photoemission spectroscopy (SRPES). The interface of Pr2O3 with SiC is reactive. Such reaction is successfully prevented by utilizing a stable interlayer derived from AlON. No elemental carbon is observed in detectable amount after Pr-Oxide deposition on AlON covered 3C-SiC and subsequent vacuum annealing. After vacuum annealing at 500 °C AlON transformed to AlN and Pr-aluminate with a small amount of CN close to the SiC surface which were thermally stable even at 900 °C. AlON hence provides a good diffusion barrier between Pr-oxide dielectric and 3C-SiC.