Abstract
Ultrathin β -Si 3 N 4 (0001) epitaxial films formed by N 2 -plasma nitridation of Si(111) substrates have been studied by photoelectron spectroscopy using synchrotron radiation. The valence band offset at the β -Si 3 N 4 /Si interface was determined by valence-band photoelectron spectra to be 1.8 eV. Furthermore, the Si 2p core-level emissions were analyzed for nitride (Si 4+ ) and subnitride (Si 3+ and Si + ) components to characterize the interface stoichiometry. In contrast to the interfaces formed by ammonia thermal nitridation and N 2 -plasma nitridation at room temperature, the interface formed by N 2 -plasma nitridation at high substrate temperature is very close to subnitride free with an abrupt composition transition. © 2009 American Institute of Physics.