Interaction between an amorphous SiNx layer made by an ion-beam technique and a cerium overlayer

An investigation of interface interactions has been performed for the ceriu m/a-silicon nitride system by means of X-ray photoelectron spectroscopy (XP S). It is found that the nitrogen atoms can transfer from silicon nitride p repared by ion-beam implantation to a cerium him deposited on the surface, forming cerium nitride at room temperature (RT). The behavior of nitrogen m igration exhibits a strong energy dependence of the nitrogen ion used in io n implantation. For a 1 keV-ion nitrided silicon substrate, a component of the N 1s spectrum grows with the thickness of Ce film at the binding energy of 1.8 eV lower than the N Is peak for silicon nitride. For a 3 keV-ion ni trided silicon substrate, however, nitrogen atoms migrate with great quanti ty from the substrate to a 15 ML, (monolayer)-thick Ce overlayer, giving a N Is spectrum with an abnormal broad peak width of 3.8 eV located at 396.0 eV. The possible causes for the great difference of nitrogen migration are mainly attributed to the different density of defects and interstitial nitr ogen atoms as well as the different chemical states of silicon nitrides pro duced in the substrate during the ion implantation with different ion-beam energies. (C) 2001 Elsevier Science B.V. All rights reserved.