Amorphous Si1−xBx ALLOYS: Atomic Fine Structure and Optical Properties

1994 ◽  
Vol 336 ◽  
Author(s):  
J. R. A. Carlsson ◽  
C. Bandmann ◽  
S. Csillag ◽  
X.-H. Li ◽  
M. Johansson
Keyword(s):  
Fine Structure ◽  
Band Gap ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Annealing Temperature ◽  
Optical Band Gap ◽  
Amorphous Phases ◽  
Annealing Temperatures ◽  
Transmission Electron ◽  
Amorphous Si

ABSTRACTIn order to study the dependence of the atomic fine structure and optical band gap of the amorphous alloy on concentration and annealing temperature, thin Si1−XBX alloy films were grown and then annealed at temperatures from 400 to 1050 °C. The films were characterized by Extended Energy Loss Fine Structure spectroscopy (EXELFS), High Resolution transmission Electron Microscopy (HREM), Auger Electron Spectroscopy (AES), and light absorption spectro-photometry. It is shown that all the amorphous Si1−XBX alloys are thermally stable (e.g., >1050 °C for x=0.6) as compared to a-Si, and that the optical band gap of the alloys increases gradually with annealing temperatures up to 700 – 900 °C. When annealed at higher temperatures the band gap increased rapidly, corresponding to a phase transformation between two amorphous phases.

Interaction of Al Films on Single Crystal Si Substrates Induced by Ion Irradiation and Post-Anneal

1983 ◽  
Vol 25 ◽  
Author(s):  
L. S. Hung ◽  
S. H. Chen ◽  
J. W. Mayer
Keyword(s):  
Electron Spectroscopy ◽  
Auger Electron ◽  
Ion Irradiation ◽  
Si Substrates ◽  
Annealing Temperatures ◽  
Transmission Electron ◽  
High Annealing ◽  
Residual Damage ◽  
Substantial Concentration ◽  
Amorphous Si

ABSTRACTRutherford backscattering and channeling techniques, transmission electron microscopy and Auger electron spectroscopy have been combined to investigate the reordering of implanted amorphous Si in the presence of an Al surface layer and the interdiffusion between these two elements. Recrystallization took place at 200°C and proceeded as the temperature increased. At 350–400°C, better epitaxial layers were obtained and channeling effects became observable. Substantial concentration of residual damage was observed in the regrown layer and persisted to high annealing temperatures. The concentration of Si in the Al film was far beyond the solid solubility at annealing temperatures. When ion implantation was performed at 200°C, the implanted layer was virtually defect free and the diffusion of Si into Al was suppressed.

Growth of CoSi2/Si Multilayer Structures

1988 ◽  
Vol 116 ◽  
Author(s):  
T. L. Ljni ◽  
P. J. Grunthaner ◽  
F. D. Schowengerdt ◽  
R W. Fathauer ◽  
J. H. Mazur ◽  
...  
Keyword(s):  
Electron Spectroscopy ◽  
Auger Electron ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Multilayer Structures ◽  
Stoichiometric Ratio ◽  
Critical Temperatures ◽  
Amorphous Si ◽  
Minimum Yield

AbstractGrowth techniques for very thin CoSi2 and Si layers for multilayer applications have been studied. CoSi2 layers without observable pinholes are grown by atechnique utilizing the room-temperature codeposition of Co and Si in stoichiometric ratio with a Si cap, followed by annealing. The crystallinity of the resulting CoSI2 layers annealed at various temperatures was studied by in-situ Rutherford backscattering channeling spectroscopy. The channeling minimum yield decreases with increasing annealing temperature, and drops sharply at ~ 570ºC. Si overgrowth was studied on CoSi2 by a Si template technique, which utilizes the deposition of a thin amorphous Si layer followed by annealing prior to the growth of the bulk of the Si layer. The effect of Si thickness and annealing temperature on Islanding of the Si overlayer was studied by Auger electron spectroscopy. Critical temperatures for a numberof Si thicknesses were identified, above which islanding of these layers occurs.

Growth of near noble metal Pd and Pt thin film silicides morphology and structure

1984 ◽  
Vol 42 ◽  
pp. 498-499
Author(s):  
E. I. Alessandrini ◽  
M. O. Aboelfotoh
Keyword(s):  
Noble Metals ◽  
Annealing Temperature ◽  
Chemical Compounds ◽  
Barrier Properties ◽  
Solid State Reactions ◽  
Transmission Electron ◽  
Stable Chemical ◽  
Metal Thickness ◽  
Amorphous Si ◽  
Si Films

Considerable interest has been generated in solid state reactions between thin films of near noble metals and silicon. These metals deposited on Si form numerous stable chemical compounds at low temperatures and have found applications as Schottky barrier contacts to silicon in VLSI devices. Since the very first phase that nucleates in contact with Si determines the barrier properties, the purpose of our study was to investigate the silicide formation of the near noble metals, Pd and Pt, at very thin thickness of the metal films on amorphous silicon.Films of Pd and Pt in the thickness range of 0.5nm to 20nm were made by room temperature evaporation on 40nm thick amorphous Si films, which were first deposited on 30nm thick amorphous Si3N4 membranes in a window configuration. The deposition rate was 0.1 to 0.5nm/sec and the pressure during deposition was 3 x 10 -7 Torr. The samples were annealed at temperatures in the range from 200° to 650°C in a furnace with helium purified by hot (950°C) Ti particles. Transmission electron microscopy and diffraction techniques were used to evaluate changes in structure and morphology of the phases formed as a function of metal thickness and annealing temperature.

Void Morphology In NiAl

2000 ◽  
Vol 646 ◽  
Author(s):  
M. Zakaria ◽  
P.R. Munroe
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Energy ◽  
Annealing Temperature ◽  
Void Formation ◽  
Dislocation Climb ◽  
Annealing Temperatures ◽  
Relative Incidence ◽  
Transmission Electron ◽  
Void Shape

ABSTRACTVoid formation in stoichiometric NiAl was studied through controlled heat treatments and transmission electron microscopy. Voids formed at temperatures as low as 400°C, but dissolved during annealing at 900°C. Both cuboidal and rhombic dodecahedral voids were observed, often at the same annealing temperature. At higher annealing temperatures (>800°C) extensive dislocation climb was noted. The relative incidence of void formation and dislocation climb can be related to the mobility of vacancies at each annealing temperature. Further, differences in void shape can be described in terms of their relative surface energy and mode of nucleation.

Auger Electron Spectroscopy and Its Application to Nanotechnology

2011 ◽  
Vol 19 (2) ◽  
pp. 12-15 ◽  
Author(s):  
S. N. Raman ◽  
D. F. Paul ◽  
J. S. Hammond ◽  
K. D. Bomben
Keyword(s):  
Electron Microscopy ◽  
Auger Electron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Imaging Techniques ◽  
Chemical Characterization ◽  
Depth Resolution ◽  
Surface Modifications ◽  
Transmission Electron ◽  
Nanoscale Characterization

Over the past decade, the field of nanotechnology has expanded, and the most heavily used nanoscale characterization/imaging techniques have been scanning probe microscopy (SPM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Although these high-resolution imaging techniques help visualize nanostructures, it is essential to understand the chemical nature of these materials and their growth mechanisms. Surface modifications in the first few nanometers can alter the bulk properties of these nanostructures, and conventional characterization techniques, including energy dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS) associated with SEM and TEM are not suited to detecting these surface modifications except in special, favorable specimens. A modern state-of-the-art scanning Auger electron spectroscopy (AES) instrument provides valuable elemental and chemical characterization of nanostructures with a lateral spatial resolution better than 10 nm and a depth resolution of a few nm. In this article we review the technique of scanning AES and highlight its unique analytical capabilities in the areas of nanotechnology, metallurgy, and semiconductors.

The Distribution of Phosphorus in Romano-British Ironwork

1990 ◽  
Vol 185 ◽  
Author(s):  
Alain E. Kaloyeros ◽  
Robert M. Ehrenreich
Keyword(s):  
Electron Microscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Materials Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Depth Study ◽  
Iron Artifacts ◽  
And Performance ◽  
Secondary Ion

AbstractPhosphorus is found to be a common impurity in many of the iron tools and weapons produced during the pre-Roman and Roman Iron Ages of Britain (600 BC - 300 AD). The effects of this impurity on the properties and performance of antiquarian materials is not well understood, however. This paper presents the initial findings of an in-depth study of the distribution, chemistry, and effects of phosphorus in Romano-British ironwork. For this purpose, two Romano-British iron artifacts from the site of Ircheoter, Northamptonshire, were examined using powerful techniques for archeological materials analysis that include electron microprobe, secondary ion mass spectroscopy (SIMS), transmission electron microscopy (TEM) with energydispersive x-ray spectroscopy capabilities (EDXS), and Auger electron spectroscopy (AES). It was found that phosphorous was indeed present in the artifacts. The phosphorus atoms were predominantly segregated at grain boundaries and thus should have led to a lowering of grain boundary cohesion and a degradation in the performance of the tools.

ZrN Diffusion Barrier in Aluminum Metallization Schemes

1982 ◽  
Vol 18 ◽  
Author(s):  
L. Krusin-Elbaum ◽  
M. Wittmer ◽  
C.-Y. Ting ◽  
J. J. Cuomo
Keyword(s):  
Grain Size ◽  
Diffusion Barrier ◽  
Annealing Temperature ◽  
Barrier Properties ◽  
Metal Nitrides ◽  
X Ray ◽  
Annealing Temperatures ◽  
Fine Grain ◽  
Transmission Electron ◽  
Aluminum Metallization

We have studied reactively sputtered ZrN, the most thermally stable of the refractory metal nitrides, for its diffusion barrier properties in aluminum metallization schemes with Rutherford backscattering spectroscopy and transmission electron microscopy (TEM). We find this compound to be very effective against aluminum diffusion up to 500 °C, independently of substrate temperature during sputtering. The useful temperature range can be extended by 50 °C with proper preannealing prior to aluminum deposition. The TEM study of the ZrN grain size as a function of annealing temperature revealed that the grain size does not change significantly upon annealing and that the grains are relatively small even at the highest annealing temperatures (about 300 Å at 900 °C). In addition, for annealing temperatures of and below 500 °C large portions of ZrN films were found to be of either amorphous or extremely fine–grain material, thus inhibiting the diffusion along grain boundaries. The presence of Zr3Al4Si5 ternary compound in samples annealed at 600 °C, as determined by X-ray analysis, may suggest that the ZrN barrier fails by decomposition of the film by aluminum.

CoSi2 Precipitate Coarsening During Formation of Buried Epitaxial Cosi2 Layers By Ion Beam Synthesis

1990 ◽  
Vol 201 ◽  
Author(s):  
R. Jebasinski ◽  
S. Mantl ◽  
K. Radermacher ◽  
P. Fichtner ◽  
W. Jăger ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Activation Energy ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Microstructural Evolution ◽  
Annealing Temperature ◽  
Ion Beam ◽  
Precipitate Coarsening ◽  
Annealing Temperatures ◽  
Transmission Electron

AbstractThe coarsening of CoSi2 precipitates and the microstructural evolution of (111) Si implanted with 200 keV Co+ ions at 350°C and fluences of 1×1016cm−2 and 6×1016cm−2 were investigated as a function of depth, annealing temperature and annealing time using Rutherford Backscattering Spectroscopy (RBS) and Transmission Electron Microscopy (TEM). After annealing cross-section TEM micrographs show a layered array of platelet-shaped precipitates with preferred facets on {111} planes. The fraction of Co-atoms, that were redistributed during the different annealing temperatures and times, has been used to determine an activation energy for the precipitate coarsening. By applying the Meechan-Brinkman and the change-of-slope methods, we obtained activation energies in the range of 3.2 – 3.6 eV.

BAND GAP SHIFT DUE TO NITROGEN DOPING, COMPOSITION GAS PRESSURE AND MICROWAVE POWER OF a-C:N THIN FILMS GROWN BY NEWLY-DEVELOPED SURFACE WAVE MICROWAVE PLASMA CVD

2004 ◽  
Vol 11 (06) ◽  
pp. 559-562
Author(s):  
M. RUSOP ◽  
S. ADHIKARI ◽  
A. M. M. OMER ◽  
S. ADHIKARY ◽  
H. UCHIDA ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Wave ◽  
Film Thickness ◽  
Band Gap ◽  
Microwave Power ◽  
Annealing Temperature ◽  
Optical Band Gap ◽  
Microwave Plasma ◽  
Gas Pressure ◽  
Developed Surface

This paper reports the band gap shifting due to nitrogen ( N 2) doping, microwave power and composition gas pressure of nitrogenated amorphous carbon ( a - C : N ) thin films deposited by newly-developed surface wave microwave plasma chemical vapor deposition (SWMP-CVD). Results show that the optical band gap decreased from 4.1 eV to 2.4 eV corresponding to the increase of N 2 doping from 0 to 5% in the gas ratio. However, further increase of N 2 doping beyond 5% did not decrease the band gap. It was found that composition gas pressure and launched MW power during film deposition also largely control the optical band gap. Investigation of annealing effects on optical band gap and film thickness of the N 2 doped films revealed that both band gap and film thickness decrease significantly with increase of annealing temperature. The optical band gap decreased from 2.4 eV to 1.1 eV, while film thickness decreases from 320 nm to 50 nm corresponding to 200 to 400°C annealing temperature. The results revealed that the properties of a - C : N can be tuned by changing the annealing temperature, composition gas pressure and microwave power of the SWMP-CVD system.

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