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Nondestructive investigation of interface states in high‐ k oxide films on Ge substrate using X‐ray absorption spectroscopy
Author(s) -
Cho DeokYong,
Jung HyungSuk,
Yu IlHyuk,
Park Won Goo,
Cho Suyeon,
Kim Useong,
Oh SeJung,
Park ByeongGyu,
Chang FanHsiu,
Lin HongJi,
Hwang Cheol Seong
Publication year - 2012
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201206059
Subject(s) - germanate , materials science , oxide , substrate (aquarium) , x ray absorption spectroscopy , analytical chemistry (journal) , spectroscopy , absorption (acoustics) , x ray photoelectron spectroscopy , permittivity , absorption spectroscopy , crystallography , chemistry , chemical engineering , optoelectronics , dielectric , optics , composite material , metallurgy , doping , oceanography , physics , engineering , chromatography , quantum mechanics , geology
The unoccupied electronic structures of 5 nm thick high permittivity ( k ) oxides (HfO 2 , ZrO 2 , and Al 2 O 3 ) and SiO 2 films on Ge substrates were examined using O K‐edge X‐ray absorption spectroscopy. Comparative studies with those on Si substrates showed contrasts in the conduction bands, which should be due to the formation of interface states. In the Al 2 O 3 and SiO 2 films, GeO 2 layers are formed at the interface and they suppress in part the formation of detrimental germanate phases. In contrast, in the HfO 2 and ZrO 2 films, no signature of the Ge‐oxide phase is observed but some germanate phases are expected to prevail, suggesting a degradation of the gate oxide characteristics. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)