Characterization of Mg Diffusion into HfO2/SiO2/Si(100) Stacked Structures and Its Impact on Detect State Densities

Akio OHTA  Daisuke KANME  Hideki MURAKAMI  Seiichiro HIGASHI  Seiichi MIYAZAKI  

IEICE TRANSACTIONS on Electronics   Vol.E94-C   No.5   pp.717-723
Publication Date: 2011/05/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E94.C.717
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Fundamentals and Applications of Advanced Semiconductor Devices)
high-k gate dielectrics,  capping layer,  HfO2,  MgO,  photoemission measurements,  

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A stacked structure consisting of ∼ 1 nm-thick MgO and ∼ 4 nm-thick HfO2 was formed on thermally grown SiO2/Si(100) by MOCVD using dipivaloymethanato (DPM) precursors, and the influences of N2 anneal on interfacial reaction and defect state density in this stacked structure were examined. The chemical bonding features of Mg atom were evaluated by using an Auger parameter independently of positive charge-up during XPS measurements. With Mg incorporation into HfO2, a slight decrease in the oxidation number of Mg was detectable. The result suggests that Mg atoms are incorporated preferentially near oxygen vacancies in the HfO2, which can be responsible for a reduction of the flat band voltage shifts observed from C-V characteristics.