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Change in crystalline structure and band alignment in atomic‐layer‐deposited Hf O 2 on In P using an annealing treatment
Author(s) -
Kang YuSeon,
Kim DaeKyoung,
Cho MannHo,
Seo JungHye,
Shon Hyun Kyong,
Lee Tae Geol,
Cho Young Dae,
Kim SunWook,
Ko DaeHong,
Kim Hyoungsub
Publication year - 2013
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201228628
Subject(s) - annealing (glass) , materials science , tetragonal crystal system , band gap , atomic layer deposition , band bending , oxide , thin film , analytical chemistry (journal) , crystallography , optoelectronics , nanotechnology , crystal structure , composite material , chemistry , metallurgy , chromatography
Abstract Changes in structural characteristics and band alignments of atomic‐layer‐deposited HfO 2 films on InP (001) as a function of annealing temperature and film thickness were investigated using various analytical techniques. After an annealing at temperatures over 500 °C, the HfO 2 films were converted into a fully crystalline structure with a tetragonal phase with no detectable interfacial layer between the film and the InP substrate. In–P–O states, produced by interfacial reactions, were increased during the post deposition annealing (PDA) process and oxides were detected in the surface region of the HfO 2 film, indicating that In and P atoms had out‐diffused. The E g value of the as‐grown HfO 2 film was found to be 5.80 ± 0.1 eV. After the PDA treatment, the optical band gap and valence band offset values were significantly affected by the interfacial oxide states between the HfO 2 film and InP substrate. Moreover, band bending in InP, due to negative space charges generated by an unstable P‐rich interfacial state during atomic layer deposition process was decreased after the annealing treatment.