Radiation-Induced Nitrogen Segregation During Electron Energy Loss Spectroscopy of Silicon Oxide-Nitride-Oxide Stacks

Published

August 1, 2003

Author(s)

Igor Levin, Richard D. Leapman, M Kovler, Y Roizin

Abstract

Electron energy loss spectroscopy in a transmission electron microscope (TEM) was used to measure elemental profiles of Si, 0 and N in the SiO_x/Si_xN_y/SiO_x/poly-Si stacks deposited on silicon. The measurements were made using (i) energy-filtered TEM and EELS spectrum-line acquisition in a fixed-beam high-resolution TEM equipped with a thermionic electron source, and a post-column energy filter, and (ii) EELS spectrum-imaging in a dedicated scanning transmission electron microscope (STEM) equipped with a cold field-emission source and an EELS spectrometer. The results revealed radiation-induced nitrogen segregation to both the Si/SiO_x and SiO_x/poly-Si interfaces; the extent of nitrogen segregation increased visibly with increasing the radiation dose. The nitrogen diffusion through the oxide layers apparently was accompanied by the diffusion of oxygen into the nitride. Under the high radiation doses, the nitride layer was transformed into an oxynitride layer, containing a substantial amount of oxygen. Artifact-free nitrogen profiles across the Si/SiO_x interfaces were obtained in STEM by scanning the beam parallel to the layers.

Citation

Applied Physics Letters

Volume

83

Issue

No. 8

Pub Type

Journals

Keywords

artifact, charge-storage, EELS, ONO, silicon nitride, silicon oxide, STEM TEM

Citation

Levin, I. , Leapman, R. , Kovler, M. and Roizin, Y. (2003), Radiation-Induced Nitrogen Segregation During Electron Energy Loss Spectroscopy of Silicon Oxide-Nitride-Oxide Stacks, Applied Physics Letters (Accessed December 11, 2024)