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Nature of chemical states of sulfur embedded in atomic‐layer‐deposited HfO 2 film on Ge substrate for interface passivation
Author(s) -
Cho DeokYong,
Seok Tae Jun,
Jin Hyun Soo,
Song Hochul,
Han Seungwu,
Park Tae Joo
Publication year - 2015
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.201510237
Subject(s) - passivation , sulfur , annealing (glass) , atomic layer deposition , forming gas , oxide , substrate (aquarium) , materials science , ion , layer (electronics) , analytical chemistry (journal) , sulfate , inorganic chemistry , chemistry , nanotechnology , metallurgy , oceanography , organic chemistry , chromatography , geology
Sulfur was embedded in atomic‐layer‐deposited (ALD) HfO 2 films grown on Ge substrate by annealing under H 2 S gas before and after HfO 2 ALD. The chemical states of sulfur in the film were examined by S K‐edge X‐ray absorption spectroscopy. It was revealed that the valences of S‐ions were mostly –2 at Ge/HfO 2 interface (GeS x or HfO 2– y S y to passivate the interface), while they were mostly +6 in HfO 2 layers (sulfates; HfO 2– z (SO 4 ) z ). The leakage current density in post‐deposi‐tion‐treated film was lower than that in pre‐deposition‐treated one. This suggests that the passivation of defects in oxide layer by sulfate ions is more effective to lower the leakage current rather than the interface defect passivation by S 2– ions. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)