Ultra thin silicon nitride films on Si(100) studied with core level photoemission

Ultra thin films of pure silicon nitride are grown on a Si(100) surface by exposing the surface to a microwave excited nitrogen plasma with a high content of N atoms at various substrate temperatures. These processes are monitored with synchrotron radiation induced core level photoemission spectroscopy. Below 500 degrees C the films grow uniformly with an amorphous character, but at higher growth temperatures, we find evidence showing that the growing nitride is microcrystalline as for Si(111), which we studied earlier. The interface between the substrate and the nitride film shows a different coordination for the Si(100) surface than for the Si(111) surface, at all temperatures. The growth of nitride in this process is self limiting with a final thickness, which increases with growth temperature. It is a clear indication from our studies that the Si(100)/nitride interface is less sharp and has a lower electrical quality than the Si(111)/nitride interface. (C) 2008 Elsevier B.V. All rights reserved.