Atomic layer deposition of hafnium oxide dielectrics on silicon and germanium substrates

David McNeill, Sekhar Bhattacharya, Haydn Wadsworth, Frederick Ruddell, Neil Mitchell, Mervyn Armstrong, Harold Gamble

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15 Citations (Scopus)

Abstract

Hafnium oxide films have been deposited at 250 °C on silicon and germanium substrates by atomic layer deposition (ALD), using tetrakis-ethylmethylamino hafnium (TEMAH) and water vapour as precursors in a modified Oxford Instruments PECVD system. Self-limiting monolayer growth has been verified, characterised by a growth rate of 0.082 nm/ cycle. Layer uniformity is approximately within ±1% of the mean value. MOS capacitors have been fabricated by evaporating aluminium electrodes. CV analysis has been used to determine the bulk and interface properties of the HfO 2, and their dependence on pre-clean schedule, deposition conditions and post-deposition annealing. The dielectric constant of the HfO 2 is typically 18. On silicon, best results are obtained when the HfO 2 is deposited on a chemically oxidised hydrophilic surface. On germanium, best results are obtained when the substrate is nitrided before HfO 2 deposition, using an in-situ nitrogen plasma treatment. © Springer Science+Business Media, LLC 2007.
Original languageEnglish
Pages (from-to)119-123
Number of pages5
JournalJournal of Materials Science: Materials in Electronics
Volume19
Issue number2
DOIs
Publication statusPublished - Feb 2008

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