A nanoanalytical investigation of elemental distributions in high-k dielectric gate stacks on silicon

Docherty, F.T. , MacKenzie, M., Craven, A.J., McComb, D.W., De Gendt, S., McFadzean, S. and McGilvery, C.M. (2008) A nanoanalytical investigation of elemental distributions in high-k dielectric gate stacks on silicon. Microelectronic Engineering, 85(1), pp. 61-64. (doi: 10.1016/j.mee.2007.03.001)

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Abstract

Two high-<i>k</i> gate stacks with the structure Si/SiO<sub>2</sub>/HfO<sub>2</sub>/TiN/poly-Si are characterised using previous termnanoanalyticalnext term electron microscopy. The effect of two key changes to the processing steps during the fabrication of the stacks is investigated. Electron energy-loss spectroscopy is used to show that the TiN layer has a very similar composition whether it is deposited by PVD or ALD. Spectrum imaging in the electron microscope was used to profile the distribution of elements across the layers in the stack. It was found that when the anneal after HfO<sub>2</sub> deposition is carried out in a NH3 atmosphere instead of an O2 atmosphere, there is diffusion of N into the SiO<sub>2</sub> and HfO<sub>2</sub> layers. There is also significant intermixing of the layers at the interfaces for both wafers.

Item Type:Articles
Additional Information:The Third IEEE International Symposium on Advanced Gate Stack Technology
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Docherty, Dr Frances and MacKenzie, Dr Maureen and Craven, Professor Alan and McFadzean, Dr Sam
Authors: Docherty, F.T., MacKenzie, M., Craven, A.J., McComb, D.W., De Gendt, S., McFadzean, S., and McGilvery, C.M.
Subjects:Q Science > QC Physics
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:Microelectronic Engineering
Publisher:Elsevier
ISSN:0167-9317
Published Online:15 March 2007

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
350671Chemistry, structure and bonding in high-k gate oxide stacksAlan CravenEngineering & Physical Sciences Research Council (EPSRC)GR/S44280/01Physics and Astronomy