Suppression of Ni Silicide Formation by Se Passivation of Si(001)

2004 ◽  
Vol 810 ◽  
Author(s):  
Janadass Shanmugam ◽  
Michael Coviello ◽  
Darshak Udeshi ◽  
Wiley P. Kirk ◽  
Meng Tao Nano
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Complementary Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Semiconductor Surface ◽  
Composition Analysis ◽  
Silicide Formation ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Thermal Stability Of

ABSTRACTValence mending of a semiconductor surface, such as the Se-passivated Si(001) surface, improves the chemical and thermal stability of the surface as compared to the bare Si(001) surface. In this paper, we report the suppression of Ni silicide formation between Ni and Si(001) through monolayer passivation of Si(001) by Se. Ni was deposited on both Se-passivated and bare Si(001) surfaces. The samples were annealed at temperatures from 400°C to 700°C. Cross-sectional TEM (Transmission Electron Microscopy) revealed that Ni on bare samples reacted with Si at 400°C and formed silicide, whereas Ni on Se-passivated samples did not react with Si at 500°C. Surface composition analysis by XPS (X-Ray Photoelectron Spectroscopy) showed pure Ni surface on Se-passivated samples annealed at 400°C and 500°C, but silicide surface on bare samples annealed at the same temperatures. Hence, Se passivation suppresses the formation of Ni silicide on the Si(001) surface by over 100°C as compared to the bare Si(001) surface. These results may have important implications in source/drain engineering in sub-100 nm Si CMOS (Complementary Metal Oxide Semiconductor) devices.

Microstructure, electrical properties, and thermal stability of Ti-based ohmic contacts to n-GaN

1999 ◽  
Vol 14 (3) ◽  
pp. 1032-1038 ◽  
Author(s):  
L. L. Smith ◽  
R. F. Davis ◽  
R-J. Liu ◽  
M. J. Kim ◽  
R. W. Carpenter
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Ohmic Contacts ◽  
Tem Analysis ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Specific Contact ◽  
Contact Resistivities ◽  
Thermal Stability Of

Single Ti layers, single TiN layers, and thin Ti films overlayered with Au were investigated as ohmic contacts to n-type (n 4.5 × 1017 to 7.4 × 1018 cm−3) single-crystal GaN (0001) films. Transmission line measurements (TLM) revealed the as-deposited TiN and Au/Ti contacts on n = 1.2 − 1018 cm−3 to be ohmic with room-temperature specific contact resistivities of 650 and 2.5 × 107minus;5 Ω cm2, respectively. Single Ti layer contacts had high resistance and were weakly rectifying in the as-deposited condition. The three contact/GaN systems exhibited a substantial decrease in resistivity after annealing; the value of ρc was also a function of the carrier concentration in the GaN. The Au/Ti contacts exhibited the lowest resistivity values yet observed in these contact studies, particularly for the more lightly doped n-GaN. The ρc for n = 1.2 × 1018 cm−3 reached 1.2 × 1026 Ω cm2; for n = 4.5 × 1017 cm−3, ρc = 7.5 × 1025 Ω cm2 after annealing both samples through 900 °C. X-ray photoelectron spectroscopy (XPS) and high-resolution cross-sectional transmission electron microscopy (X-TEM) analysis revealed the formation of TiN at the interface of annealed Ti layers in contact with GaN, which is believed to be beneficial for ohmic contact performance on n-GaN.

The Effects of Nitrogen on Electrical and Structural Properties in TaSixNy/SiO2/p-Si MOS Capacitors

2002 ◽  
Vol 716 ◽  
Author(s):  
You-Seok Suh ◽  
Greg Heuss ◽  
Jae-Hoon Lee ◽  
Veena Misra
Keyword(s):  
Structural Properties ◽  
Electron Spectroscopy ◽  
Oxygen Diffusion ◽  
Gate Dielectric ◽  
Barrier Properties ◽  
Reaction Rates ◽  
Cross Sectional ◽  
Mos Capacitors ◽  
Transmission Electron ◽  
Thermal Stability Of

AbstractIn this work, we report the effects of nitrogen on electrical and structural properties in TaSixNy /SiO2/p-Si MOS capacitors. TaSixNy films with various compositions were deposited by reactive sputtering of TaSi2 or by co-sputtering of Ta and Si targets in argon and nitrogen ambient. TaSixNy films were characterized by Rutherford backscattering spectroscopy and Auger electron spectroscopy. It was found that the workfunction of TaSixNy (Si>Ta) with varying N contents ranges from 4.2 to 4.3 eV. Cross-sectional transmission electron microscopy shows no indication of interfacial reaction or crystallization in TaSixNy on SiO2, resulting in no significant increase of leakage current in the capacitor during annealing. It is believed that nitrogen retards reaction rates and improves the chemical-thermal stability of the gate-dielectric interface and oxygen diffusion barrier properties.

Properties of MOS Structure Fabricated on 3C-SiC Grown by Reactive Magnetron Sputtering.

1994 ◽  
Vol 339 ◽  
Author(s):  
R. Turan ◽  
Q. Wahab ◽  
L. Hultman ◽  
M. Willander ◽  
J. -E. Sundgren
Keyword(s):  
Magnetron Sputtering ◽  
Interface State ◽  
State Density ◽  
Reactive Magnetron Sputtering ◽  
Oxide Semiconductor ◽  
Reactive Magnetron ◽  
Cross Sectional ◽  
Mos Structure ◽  
Transmission Electron ◽  
Wide Bandgap Materials

ABSTRACTWe report the fabrication and the characterization of Metal Oxide Semiconductor (MOS) structure fabricated on thermally oxidized 3C-SiC grown by reactive magnetron sputtering. The structure and the composition of the SiO2 layer was studied by cross-sectional transmission electron microscopy (XTEM) Auger electron spectroscopy (AES). Homogeneous stoichiometric SiO2 layers formed with a well-defined interface to the faceted SiC(lll) top surface. Electrical properties of the MOS capacitor have been analyzed by employing the capacitance and conductance techniques. C-V curves shows the accumulation, depletion and deep depletion phases. The capacitance in the inversion regime is not saturated, as usually observed for wide-bandgap materials. The unintentional doping concentration determined from the 1/C2 curve was found to be as low as 2.8 × 1015 cm-3. The density of positive charges in the grown oxide and the interface states have been extracted by using high-frequency C-V and conductance techniques. The interface state density has been found to be in the order of 1011cm2-eV-1.

scholarly journals Dual Light- and pH-Responsive Composite of Polyazo-Derivative Grafted Cellulose Nanocrystals

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1725 ◽  
Author(s):  
Xiaohong Liu ◽  
Ming Li ◽  
Xuemei Zheng ◽  
Elias Retulainen ◽  
Shiyu Fu
Keyword(s):  
Cellulose Nanocrystals ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
X Ray Diffraction ◽  
Responsive Materials ◽  
X Ray ◽  
Ph Response ◽  
Transmission Electron ◽  
Ft Ir ◽  
Hexyl Methacrylate

As a type of functional group, azo-derivatives are commonly used to synthesize responsive materials. Cellulose nanocrystals (CNCs), prepared by acid hydrolysis of cotton, were dewatered and reacted with 2-bromoisobuturyl bromide to form a macro-initiator, which grafted 6-[4-(4-methoxyphenyl-azo) phenoxy] hexyl methacrylate (MMAZO) via atom transfer radical polymerization. The successful grafting was supported by Fourier transform infrared spectroscopy (FT-IR) and Solid magnetic resonance carbon spectrum (MAS 13C-NMR). The morphology and surface composition of the poly{6-[4-(4-methoxyphenylazo) phenoxy] hexyl methacrylate} (PMMAZO)-grafted CNCs were confirmed with Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The grafting rate on the macro-initiator of CNCs was over 870%, and the polydispersities of branched polymers were narrow. The crystal structure of CNCs did not change after grafting, as determined by X-ray diffraction (XRD). The polymer PMMAZO improved the thermal stability of cellulose nanocrystals, as shown by thermogravimetry analysis (TGA). Then the PMMAZO-grafted CNCs were mixed with polyurethane and casted to form a composite film. The film showed a significant light and pH response, which may be suitable for visual acid-alkali measurement and reversible optical storage.

Carbon Supported Pt+Os Catalysts for Methanol Oxidation

2002 ◽  
Vol 57 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Gülsün Gökağaç ◽  
Brendan J. Kennedy
Keyword(s):  
Methanol Oxidation ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Carbon Support ◽  
Methanol Oxidation Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Metal Metal ◽  
Metal Support

11% Pt/C, 10% Pt + 1%Os/C, 9% Pt + 2%Os/C, 8% Pt + 3%Os/C, 7% Pt + 4%Os/C, 6% Pt + 5%Os/C and 5%Pt + 6% Os/C catalysts have been prepared for methanol oxidation reaction. Transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and cyclic voltammetry have been used to understand the nature of the species present in these catalysts. 7% Pt + 4% Os/C was the most active catalyst, while 8% Pt + 3% Os/C was the least active one. It is found that the metal particle size and distribution on the carbon support, the surface composition and the oxidation states of the metal particles, the metal-metal and metal support interactions are important parameters to define the activity of the catalyst.

Direct Deposition Reactions Between Nickel and Silicon Substrates

1993 ◽  
Vol 311 ◽  
Author(s):  
Lin Zhang ◽  
Douglas G. Ivey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Substrates ◽  
Silicide Formation ◽  
Cross Sectional ◽  
Deposition Rates ◽  
Plan View ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron

ABSTRACTSilicide formation through deposition of Ni onto hot Si substrates has been investigated. Ni was deposited onto <100> oriented Si wafers, which were heated up to 300°C, by e-beam evaporation under a vacuum of <2x10-6 Torr. The deposition rates were varied from 0.1 nm/s to 6 nm/s. The samples were then examined by both cross sectional and plan view transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy and electron diffraction. The experimental results are discussed in terms of a new kinetic model.

A STUDY OF ALUMINA THIN FILMS GROWN BY LOW PRESSURE MOCVD: XPS AND AES

2002 ◽  
Vol 16 (08) ◽  
pp. 1261-1267 ◽  
Author(s):  
M. P. SINGH ◽  
S. A. SHIVASHANKAR ◽  
T. SHRIPATHI
Keyword(s):  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Alumina Film ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Low Pressure Mocvd ◽  
Substrate Temperatures

We have studied the chemical composition of alumina ( Al 2 O 3) films grown on Si(100) at different substrate temperatures by metalorganic chemical vapor deposition (MOCVD) using aluminium acetylactonate { Al(acac) 3} as the precursor. We have found that the resulting films of Al 2 O 3 contain substantial amounts of carbon. X-ray photoelectron spectroscopy (XPS) was employed to study the chemical state of carbon present in such films. The XPS spectrum reveals that the carbon present in Al 2 O 3 film is graphitic in nature. Auger electron spectroscopy (AES) was employed to study the distribution of carbon in the Al 2 O 3 films. The AES depth profile reveals that carbon is present throughout the film. The AES study on Al 2 O 3 films corroborates the XPS findings. An investigation of the Al 2 O 3/ Si (100) interface was carried out using cross-sectional transmission electron microscopy (XTEM). The TEM study reveals textured growth of alumina film on Si(100), with very fine grains of alumina embedded in an amorphous carbon-containing matrix.

Thermal Stability and Analysis of Laser Deposited Platinum Films

2000 ◽  
Vol 624 ◽  
Author(s):  
G.J. Berry ◽  
J.A. Cairns ◽  
M.R. Davidson ◽  
Y.C. Fan ◽  
A.G. Fitzgerald ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Elevated Temperatures ◽  
Surface Composition ◽  
Direct Write ◽  
Force Microscopy ◽  
Annealing Conditions ◽  
Atomic Force ◽  
Transmission Electron ◽  
Induced Decomposition

ABSTRACTAs the trend towards device miniaturisation continues, surface effects and the thermal stability of metal deposits becomes increasingly important. We present here a study of the morphology and composition of platinum films, produced by the UV-induced decomposition of organometallic materials, under various annealing conditions. The surface composition of the metal deposits was studied by X-ray photoelectron spectroscopy, both as-deposited and following thermal treatment. In addition, the morphology of the surface was studied by atomic force microscopy which enabled the investigation of film restructuring. These studies were performed over a range of temperatures up to 1000°C in air and up to 600°C in reducing environments. Complementary information regarding the film morphology has been obtained from transmission electron microscopy. The data has been used to provide an insight into the effects of elevated temperatures on metal films deposited by a direct write method

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