Interfacial Characteristics for LaAlO3 Gate Dielectric on S Passivated GaAs Substrate

2012 ◽  
Vol 629 ◽  
pp. 127-130
Author(s):  
Ting Ting Jia ◽  
Xing Hong Cheng ◽  
Duo Cao ◽  
Da Wei Xu ◽  
Chao Xia ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Gate Dielectric ◽  
Atomic Layer ◽  
Interface Morphology ◽  
X Ray ◽  
Transmission Electron ◽  
Layer Deposition ◽  
Chemical Bonding State ◽  
Capacitance Voltage ◽  
Sulfur Passivation

In this work, we present the results of an investigation into the effectiveness of varying ammonium sulphide (NH4)2S concentrations in the passivation of n-type GaAs. Samples were degreased and immersed in aqueous (NH4)2S solutions of concentrations 22% and 10%for 10 min at 295 K, immediately prior to plasma enhanced atomic layer deposition of LaAlO3. The chemical bonding state of (NH4)2S treated GaAs surface were investigated by X-ray photoelectron spectroscopy (XPS), which indicate that Sulfur passivation can reduce intrerfacial GaAs-oxide formation. Transmission electron microscopy (TEM) was implemented to characterize the interface morphology. Finally, capacitance-voltage (C-V) and leakage current density-voltage (J-V) measurement were used to characterize the electrical properties of LaAlO3 films.

The Interface Properties of La2O3/GaAs System by Surface Passivation

2012 ◽  
Vol 557-559 ◽  
pp. 1815-1818 ◽  
Author(s):  
Ting Ting Jia ◽  
Xing Hong Cheng ◽  
Duo Cao ◽  
Da Wei Xu ◽  
You Wei Zhang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Passivation ◽  
Gate Dielectric ◽  
Surface Preparation ◽  
Atomic Layer ◽  
Native Oxide ◽  
Atomic Force ◽  
Transmission Electron ◽  
Layer Deposition

In this work, La2O3 gate dielectric film was deposited by plasma enhanced atomic layer deposition. we investigate the effect of surface preparation of GaAs substrate, for example, native oxide, S-passivation, and NH3 plasma in situ treatment. The interfacial reaction mechanisms of La2O3 on GaAs is studied by means of X-ray photoelectron spectroscopy(XPS), high-resolution transmission electron microscopy(HRTEM) and atomic force microscope (AFM). As-O bonding is found to get effectively suppressed in the sample GaAs structures with both S-passivation and NH3 plasma surface treatments.

Correlation of Phase Segregation and Electrical Properties of Low-Power MOSFETs with Hf-based Silicate Gate Dielectric Layers and TaN Metal Gates

2006 ◽  
Vol 917 ◽  
Author(s):  
Jasmine Petry ◽  
Chris Rittersma ◽  
Georgios Vellianitis ◽  
Vincent Cosnier ◽  
Thierry Conard ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Gate Dielectric ◽  
Phase Segregation ◽  
Atomic Layer ◽  
Gate Leakage ◽  
Electrical Measurements ◽  
Metal Gates ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Transmission Electron ◽  
Layer Deposition

AbstractThe need for nitridation of Hf silicate is controversial. On one hand, it has not been proven that the nitridation is mandatory to have working devices and on the other hand, it is known to increase the charge density. In this paper, we present a detailed comprehensive study of the role and the need for nitridation of Hf-based silicates deposited by Atomic Layer Deposition (ALD). The results are based on a correlation of Fourier-Transformed Infrared Spectroscopy (FT-IR), X-ray Photoelectron Spectroscopy (XPS), High-resolution Transmission Electron Microscopy (HR-TEM) and electrical measurements (gate leakage and mobility).It was observed that the phase segregation in gate dielectrics is not detrimental for the gate leakage density at room temperature. However, the leakage current is significantly increased at higher temperature. The incorporation of nitrogen was either done by NH3 anneal (at 800C) or by Decoupled Plasma Nitridation (DPN – 25.9kJ). While the DPN or NH3 anneal prevent phase segregation for 50% Hf silicate, only the NH3 anneal helps prevent the phase segregation of Hf-rich silicate. Furthermore, the NH3 anneal increases the interfacial thickness, which produces a very low gate leakage with only 10% loss in mobility at high field. Interestingly, DPN followed by O2 anneal leads to an advantageous phase segregation of the Hf-rich silicate by transforming the silicate in a HfO2/SiO2-like stack.As a conclusion, not only the phase segregation of the silicate does not always lead to shorted devices, but it can be beneficial in terms of mobility. However, the phase segregation seems to be responsible for an enlarged trap-assisted conduction mechanism at high temperature. But even if the 50% Hf silicates non-nitrided leads to working devices, the incorporation of nitrogen in the stack improves the Jg/CET trends and is therefore beneficial.

Interface and Electrical Properties of Atomic-layer-deposited HfAlO Gate Dielectric for N-channel GaAs MOSFETs

2009 ◽  
Vol 1155 ◽  
Author(s):  
Rahul Suri ◽  
Daniel J Lichtenwalner ◽  
Veena Misra
Keyword(s):  
Electrical Properties ◽  
Photoelectron Spectroscopy ◽  
Gate Dielectric ◽  
Atomic Layer ◽  
Oxide Thickness ◽  
Gate Leakage Current ◽  
X Ray ◽  
Layer Deposition ◽  
Post Deposition ◽  
Gallium Oxides

AbstractThe interface and electrical properties of HfAlO dielectric formed by atomic layer deposition (ALD) on sulfur-passivated GaAs were investigated. X-ray photoelectron spectroscopy (XPS) revealed the absence of arsenic oxides at the HfAlO/GaAs interface after dielectric growth and post-deposition annealing at 500 °C. A minimal increase in the amount of gallium oxides at the interface was detected between the as-deposited and annealed conditions highlighting the effectiveness of HfAlO in suppressing gallium oxide formation. An equivalent oxide thickness (EOT) of ∼ 2 nm has been achieved with a gate leakage current density of less than 10-4 A/cm2. These results testify a good dielectric interface with minimal interfacial oxides and open up potential for further investigation of HfAlO/GaAs gate stack properties to determine its viability for n-channel MOSFETs.

scholarly journals Preparation of Al2O3 and AlN Nanotubes by Atomic Layer Deposition

2012 ◽  
Vol 1408 ◽  
Author(s):  
Cagla Ozgit ◽  
Fatma Kayaci ◽  
Inci Donmez ◽  
Engin Cagatay ◽  
Tamer Uyar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Atomic Layer Deposition ◽  
Photoelectron Spectroscopy ◽  
Atomic Layer ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Layer Deposition ◽  
High Resolution Tem ◽  
Uniform Wall

ABSTRACTAl2O3 and AlN nanotubes were fabricated by depositing conformal thin films via atomic layer deposition (ALD) on electrospun nylon 66 (PA66) nanofiber templates. Depositions were carried out at 200°C, using trimethylaluminum (TMAl), water (H2O), and ammonia (NH3) as the aluminum, oxygen, and nitrogen precursors, respectively. Deposition rates of Al2O3 and AlN at this temperature were ∼1.05 and 0.86 Å/cycle. After the depositions, Al2O3- and AlN-coated nanofibers were calcinated at 500°C for 2 h in order to remove organic components. Nanotubes were characterized by using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). AlN nanotubes were polycrystalline as determined by high resolution TEM (HR-TEM) and selected area electron diffraction (SAED). TEM images of all the samples reported in this study indicated uniform wall thicknesses.

Spectroscopic study of La2O3 thin films deposited by indigenously developed plasma-enhanced atomic layer deposition system

2018 ◽  
Vol 32 (19) ◽  
pp. 1840074 ◽  
Author(s):  
Viral Barhate ◽  
Khushabu Agrawal ◽  
Vilas Patil ◽  
Sumit Patil ◽  
Ashok Mahajan
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Spectroscopic Study ◽  
Photoelectron Spectroscopy ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Layer Deposition

The spectroscopic study of La2O3 thin films deposited over Si and SiC at low RF power of 25 W by using indigenously developed plasma-enhanced atomic layer deposition (IDPEALD) system has been investigated. The tris (cyclopentadienyl) lanthanum (III) and O2 plasma were used as a source precursor of lanthanum and oxygen, respectively. The [Formula: see text]1.2 nm thick La2O3 over SiC and Si has been formed based on our recipe confirmed by means of cross-sectional transmission electron microscopy. The structural characterization of deposited films was performed by means of X-ray photoelectron Spectroscopy (XPS) and X-ray Diffraction (XRD). The XPS result confirms the formation of 3[Formula: see text] oxidation state of the lanthania. The XRD results reveals that, deposited La2O3 films deposited on SiC are amorphous in nature compare to that of films on Si. The AFM micrograph shows the lowest roughness of 0.26 nm for 30 cycles of La2O3 thin films.

scholarly journals Air Annealing Effect on Oxygen Vacancy Defects in Al-doped ZnO Films Grown by High-Speed Atmospheric Atomic Layer Deposition

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5043
Author(s):  
Chia-Hsun Hsu ◽  
Xin-Peng Geng ◽  
Wan-Yu Wu ◽  
Ming-Jie Zhao ◽  
Xiao-Ying Zhang ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Band Gap ◽  
Photoelectron Spectroscopy ◽  
High Speed ◽  
Oxygen Vacancies ◽  
Annealing Temperature ◽  
Atomic Layer ◽  
Zno Films ◽  
X Ray ◽  
Layer Deposition

In this study, aluminum-doped zinc oxide (Al:ZnO) thin films were grown by high-speed atmospheric atomic layer deposition (AALD), and the effects of air annealing on film properties are investigated. The experimental results show that the thermal annealing can significantly reduce the amount of oxygen vacancies defects as evidenced by X-ray photoelectron spectroscopy spectra due to the in-diffusion of oxygen from air to the films. As shown by X-ray diffraction, the annealing repairs the crystalline structure and releases the stress. The absorption coefficient of the films increases with the annealing temperature due to the increased density. The annealing temperature reaching 600 °C leads to relatively significant changes in grain size and band gap. From the results of band gap and Hall-effect measurements, the annealing temperature lower than 600 °C reduces the oxygen vacancies defects acting as shallow donors, while it is suspected that the annealing temperature higher than 600 °C can further remove the oxygen defects introduced mid-gap states.

scholarly journals Structure-Dependent Mechanical Properties of ALD-Grown Nanocrystalline BiFeO3Multiferroics

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Anna Majtyka ◽  
Anna Nowak ◽  
Benoît Marchand ◽  
Dariusz Chrobak ◽  
Mikko Ritala ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Photoelectron Spectroscopy ◽  
Present Report ◽  
Structural Evolution ◽  
Atomic Layer ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Layer Deposition ◽  
Pertinent Information

The present paper pertains to mechanical properties and structure of nanocrystalline multiferroic BeFiO3(BFO) thin films, grown by atomic layer deposition (ALD) on the Si/SiO2/Pt substrate. The usage of sharp-tip-nanoindentation and multiple techniques of structure examination, namely, grazing incidence X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectrometry, enabled us to detect changes in elastic properties(95 GPa≤E≤118 GPa)and hardness(4.50 GPa≤H≤7.96 GPa)of BFO after stages of annealing and observe their relation to the material’s structural evolution. Our experiments point towards an increase in structural homogeneity of the samples annealed for a longer time. To our best knowledge, the present report constitutes the first disclosure of nanoindentation mechanical characteristics of ALD-fabricated BeFiO3, providing a new insight into the phenomena that accompany structure formation and development of nanocrystalline multiferroics. We believe that our systematic characterization of the BFO layers carried out at consecutive stages of their deposition provides pertinent information which is needed to control and optimize its ALD fabrication.

scholarly journals Porous Silicon-Zinc Oxide Nanocomposites Prepared by Atomic Layer Deposition for Biophotonic Applications

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1987 ◽  
Author(s):  
Mykola Pavlenko ◽  
Valerii Myndrul ◽  
Gloria Gottardi ◽  
Emerson Coy ◽  
Mariusz Jancelewicz ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Optical Properties ◽  
Porous Silicon ◽  
Atomic Layer Deposition ◽  
Photoelectron Spectroscopy ◽  
Atomic Layer ◽  
Visible Range ◽  
Optical Biosensing ◽  
X Ray ◽  
Layer Deposition

In the current research, a porous silicon/zinc oxide (PSi/ZnO) nanocomposite produced by a combination of metal-assisted chemical etching (MACE) and atomic layer deposition (ALD) methods is presented. The applicability of the composite for biophotonics (optical biosensing) was investigated. To characterize the structural and optical properties of the produced PSi/ZnO nanocomposites, several studies were performed: scanning and transmission electron microscopy (SEM/TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance, and photoluminescence (PL). It was found that the ALD ZnO layer fully covers the PSi, and it possesses a polycrystalline wurtzite structure. The effect of the number of ALD cycles and the type of Si doping on the optical properties of nanocomposites was determined. PL measurements showed a “shoulder-shape” emission in the visible range. The mechanisms of the observed PL were discussed. It was demonstrated that the improved PL performance of the PSi/ZnO nanocomposites could be used for implementation in optical biosensor applications. Furthermore, the produced PSi/ZnO nanocomposite was tested for optical/PL biosensing towards mycotoxins (Aflatoxin B1) detection, confirming the applicability of the nanocomposites.

Atomic Layer Deposition of TiN below 600 K Using N2H4

2018 ◽  
Vol 282 ◽  
pp. 232-237
Author(s):  
Adam Hinckley ◽  
Anthony Muscat
Keyword(s):  
Growth Rate ◽  
Atomic Layer Deposition ◽  
Titanium Nitride ◽  
Photoelectron Spectroscopy ◽  
Film Growth ◽  
Detection Limits ◽  
Atomic Layer ◽  
Volatile Species ◽  
X Ray ◽  
Layer Deposition

Atomic layer deposition (ALD) was used to grow titanium nitride (TiN) on SiO2with TiCl4and N2H4. X-ray photoelectron spectroscopy (XPS) and ellipsometry were used to characterize film growth. A hydrogen-terminated Si (Si-H) surface was used as a reference to understand the reaction steps on SPM cleaned SiO2. The growth rate of TiN at 573 K doubled on Si-H compared to SiO2because of the formation of Si-N bonds. When the temperature was raised to 623 K, O transferred from Ti to Si to form Si-N when exposed to N2H4. Oxygen and Ti could be removed at 623 K by TiCl4producing volatile species. The added surface reactions reduce the Cl in the film below detection limits.

Experimental and First-Principles Studies of the Band Alignment at the HfO2/4H-SiC (0001) Interface

2006 ◽  
Vol 527-529 ◽  
pp. 1071-1074 ◽  
Author(s):  
Carey M. Tanner ◽  
Jong Woo Choi ◽  
Jane P. Chang
Keyword(s):  
Conduction Band ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Atomic Layer ◽  
Band Alignment ◽  
Functional Theory ◽  
X Ray ◽  
Conduction Band Offset ◽  
Mos Devices ◽  
Layer Deposition

The electronic properties of HfO2 films on 4H-SiC were investigated to determine their suitability as high-κ dielectrics in SiC power MOS devices. The band alignment at the HfO2/4HSiC interface was determined by X-ray photoelectron spectroscopy (XPS) and supported by density functional theory (DFT) calculations. For the experimental study, HfO2 films were deposited on ntype 4H-SiC by atomic layer deposition (ALD). XPS analysis yielded valence and conduction band offsets of 1.69 eV and 0.75 eV, respectively. DFT predictions based on two monoclinic HfO2/4HSiC (0001) structures agree well with this result. The small conduction band offset suggests the potential need for further interface engineering and/or a buffer layer to minimize electron injection into the gate oxide.

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