Interfacial reaction induced phase separation in La{sub x}Hf{sub y}O films

Journal Article · Wed Jun 15 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3598084· OSTI ID:21538459

Ma, J W; Lee, W J; Cho, M -H ^[1]; Lee, K M; Sohn, H C ^[2]; Kim, C S ^[3]; Cho, H J ^[4]

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1. Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749 (Korea, Republic of)
2. Department of Material Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of)
3. Korea Research Institute of Standards and Science, Daejeon 305-540 (Korea, Republic of)
4. Process Development Team, Semiconductor R and D Center, Samsung Electronics Co., LTD, Gyeonggi-Do 449-711 (Korea, Republic of)

Amorphous La{sub x}Hf{sub y}O films containing La at concentrations (x) of 50 and 20% were prepared by atomic layer deposition on ultrathin SiO{sub 2} films (1 nm). We examined the electronic structures and microstructures of the La{sub x}Hf{sub y}O films by x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS), and x-ray diffraction (XRD). Phase separation into La{sub 2}O{sub 3} and HfO{sub 2} was observed in the La{sub x}Hf{sub y}O films subjected to annealing temperatures over 900 deg. C, although the mixture of La{sub 2}O{sub 3} and HfO{sub 2} is thermodynamically stable. The structural changes that occurred as the result of phase separation were dependent on the concentrations of La and Hf in the films. During the annealing treatment, silicate was produced due to interfacial reactions and the interfacial reactions were found to be dependent on the La{sub 2}O{sub 3} content in the La{sub x}Hf{sub y}O films, which has a significant influence on the phase separation process and resulting film structure.

• OSTI ID: 21538459
• Journal Information: Journal of Applied Physics, Vol. 109, Issue 12; Other Information: DOI: 10.1063/1.3598084; (c) 2011 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AMORPHOUS STATE
ANNEALING
CRYSTAL STRUCTURE
ELECTRONIC STRUCTURE
HAFNIUM OXIDES
INTERFACES
LANTHANUM OXIDES
LAYERS
MICROSTRUCTURE
MIXTURES
SEPARATION PROCESSES
SILICON OXIDES
THERMODYNAMICS
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY
X-RAY SPECTROSCOPY
CHALCOGENIDES
COHERENT SCATTERING
DIFFRACTION
DISPERSIONS
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
FILMS
HAFNIUM COMPOUNDS
HEAT TREATMENTS
LANTHANUM COMPOUNDS
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
RARE EARTH COMPOUNDS
REFRACTORY METAL COMPOUNDS
SCATTERING
SILICON COMPOUNDS
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS