Interfacial and structural properties of sputtered HfO{sub 2} layers

Journal Article · Wed Jul 01 00:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3153953· OSTI ID:21359299

Aygun, G ^[1]; Yildiz, I ^[2]

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1. Department of Physics, Izmir Institute of Technology, Urla, TR-35430 Izmir (Turkey)
2. Department of Physics, Middle East Technical University, TR-06531 Ankara (Turkey)

Magnetron sputtered HfO{sub 2} layers formed on a heated Si substrate were studied by spectroscopic ellipsometer (SE), x-ray diffraction (XRD), Fourier transform infrared (FTIR), and x-ray photoelectron spectroscopy (XPS) depth profiling techniques. The results show that the formation of a SiO{sub x} suboxide layer at the HfO{sub 2}/Si interface is unavoidable. The HfO{sub 2} thickness and suboxide formation are highly affected by the growth parameters such as sputtering power, O{sub 2}/Ar gas ratio during sputtering, sputtering time, and substrate temperature. XRD spectra show that the deposited film has (111) monoclinic phase of HfO{sub 2}, which is also supported by FTIR spectra. The atomic concentration and chemical environment of Si, Hf, and O have been measured as a function of depth starting from the surface of the sample by XPS technique. It shows that HfO{sub 2} layers of a few nanometers are formed at the top surface. Below this thin layer, Si-Si bonds are detected just before the Si suboxide layer, and then the Si substrate is reached during the depth profiling by XPS. It is clearly understood that the highly reactive sputtered Hf atoms consume some of the oxygen atoms from the underlying SiO{sub 2} to form HfO{sub 2}, leaving Si-Si bonds behind.

• OSTI ID: 21359299
• Journal Information: Journal of Applied Physics, Vol. 106, Issue 1; Other Information: DOI: 10.1063/1.3153953; (c) 2009 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL GROWTH
DEPOSITION
DIELECTRIC MATERIALS
ELLIPSOMETERS
ELLIPSOMETRY
FOURIER TRANSFORMATION
HAFNIUM OXIDES
INFRARED SPECTRA
LAYERS
MONOCLINIC LATTICES
OXYGEN
SEMICONDUCTOR MATERIALS
SILICA
SILICON
SILICON OXIDES
SPUTTERING
SUBSTRATES
THIN FILMS
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY
CHALCOGENIDES
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRON SPECTROSCOPY
ELEMENTS
FILMS
HAFNIUM COMPOUNDS
INTEGRAL TRANSFORMATIONS
MATERIALS
MEASURING INSTRUMENTS
MEASURING METHODS
MINERALS
NONMETALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
POLARIMETERS
REFRACTORY METAL COMPOUNDS
SCATTERING
SEMIMETALS
SILICON COMPOUNDS
SPECTRA
SPECTROSCOPY
TRANSFORMATIONS
TRANSITION ELEMENT COMPOUNDS