Analyses of composition and chemical shift of silicon oxynitride film using energy-filtering transmission electron microscope based spatially resolved electron energy loss spectroscopy

Composition and chemical shift analyses of a multilayer (SiO2/Si3N4/SiOxNy/ Si) were performed by spatially resolved electron energy loss spectroscopy (EELS) using an energy-filtering transmission electron microscope (EFTEM). Using EFTEM-based spatially resolved EELS (EFTEM-SREELS), many spectra from different positions on the specimen can be obtained simultaneously without scanning the focused electron beam. It has been shown that nitrogen is acc umulated at the interface between SiOxNy and Si, and the full-width at half -maximum of the nitrogen accumulation is 1.7 nm. The nitrogen energy loss s pectrum at the interface shows a chemical shift of about 0.5 eV in comparis on with that of Si3N4 Based on molecular orbital calculations, the nitrogen at the interface appears to be included in N-Si-O bonds. The EFTEM-SREELS is found to be effective in obtaining precise line profiles of composition and chemical shift. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.