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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:42 |
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Conference: Bucharest University Faculty of Physics 2021 Meeting
Section: Solid State Physics and Materials Science
Title:
Structural and electric properties of ultrathin layers
obtained by atomic layer deposition
Authors:
George Ormenisan, Ciceron Berbecaru
Affiliation:
University of Bucharest, Faculty of Physics, Atomistilor 405, Magurele, Ilfov, Romania
E-mail
berbecaru2ciceron@yahoo.com , ormenisangeorge94@gmail.com
Keywords:
nanometric structures, ALD deposition, High-k oxides, ferroelectric HfO2
Abstract:
Ultrathin HfO2 layers on p-silicon (p-Si) were obtained employing Atomic Layer Deposition (ALD) method, [1]. Scanning Electron Microscopy with Energy-Dispersive X-ray spectroscopy (SEM-EDX) and X-ray Photoelectron Spectroscopy (XPS) were used for structural characterization of the as deposited layers. Hioki type LCR bridges were used to investigate electrical properties of samples. All experiments were performed at room temperature. SEM-EDX revealed the presence of HfO2 on the p-Si substrate with well-defined interfaces. XPS analysis shows well evidenced peaks of the HfO2 and other constituents. An ultrathin layer of Si oxides at the interface of HfO2 with p-Si it has been shown to exist after carefully corrosion of the HfO2 layer with Ar. The interlayer diffusion has been not excluded. Capacity- Voltage (C-V) experiments showed thin and counterclockwise hysteresis curves. The investigation of dielectric parameters performed at different frequencies revealed high values of the series resistance even at high frequencies. Also in the C-V measurements, conductance curves show a typical influence of the volume of the substrate covering the response of the trapping centers located at the interface of HfO2 with p-Si [2],[3]. It was concluded that high quality of HfO2 layers on p-Si substrates with high quality interfaces could be obtained by ALD method. Interfaces are also of great importance in the properties of devices based on ultra-thin high-K layers such as HfO2.
References:
[1] F. Nastase et. al., Nanotechnologies and nanomaterials for various applications, Ed. Acad. Rom., 2018.
[2] E.H. Nicollian, J.R. Brews, MOS physics and technology, Wiley, New York, 1982.
[3] D. K. Schroder, Semiconductor material and device characterization, John Wiley & Sons, Inc., 2006.
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