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

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.

1994 ◽  
Vol 336 ◽  
Author(s):  
J. R. A. Carlsson ◽  
C. Bandmann ◽  
S. Csillag ◽  
X.-H. Li ◽  
M. Johansson

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.


1995 ◽  
Vol 382 ◽  
Author(s):  
G.R. Carlow ◽  
T.D. Lowes ◽  
M. Grunwell ◽  
M. Zinke-Allmang

ABSTRACTWe present results on the evolution of Co/Ge films on Si(100) substrates. Room temperature deposition of 18 nm thick Ge films followed by 5 nm thick Co films was done by Molecular Beam Epitaxy (MBE) and then post-deposited annealing was done at 700 C. Using combinations of Scanning electron microscopy, Auger electron spectroscopy and Rutherford backscattering spectroscopy, we determine that the Co and Ge are clustering on the Si surface at these annealing temperatures. During the clustering, the Co is diffusing into the Si substrate leaving a Ge-rich clustered morphology. To test the effect of the Si substrate on the evolution of the films, Co films were deposited on Ge(100) substrates and annealed at 700 C. Clustered morphologies are seen on the Ge substrates and Co in-diffusion is also occurring. The morphologies on the Ge substrates are significantly different from those on the Si substrates.


Author(s):  
L. Hultman ◽  
C.-H. Choi ◽  
R. Kaspi ◽  
R. Ai ◽  
S.A. Barnett

III-V semiconductor films nucleate by the Stranski-Krastanov (SK) mechanism on Si substrates. Many of the extended defects present in the films are believed to result from the island formation and coalescence stage of SK growth. We have recently shown that low (-30 eV) energy, high flux (4 ions per deposited atom), Ar ion irradiation during nucleation of III-V semiconductors on Si substrates prolongs the 1ayer-by-layer stage of SK nucleation, leading to a decrease in extended defect densities. Furthermore, the epitaxial temperature was reduced by >100°C due to ion irradiation. The effect of ion bombardment on the nucleation mechanism was explained as being due to ion-induced dissociation of three-dimensional islands and ion-enhanced surface diffusion.For the case of InAs grown at 380°C on Si(100) (11% lattice mismatch), where island formation is expected after ≤ 1 monolayer (ML) during molecular beam epitaxy (MBE), in-situ reflection high-energy electron diffraction (RHEED) showed that 28 eV Ar ion irradiation prolonged the layer-by-layer stage of SK nucleation up to 10 ML. Otherion energies maintained layer-by-layer growth to lesser thicknesses. The ion-induced change in nucleation mechanism resulted in smoother surfaces and improved the crystalline perfection of thicker films as shown by transmission electron microscopy and X-ray rocking curve studies.


2011 ◽  
Vol 19 (2) ◽  
pp. 12-15 ◽  
Author(s):  
S. N. Raman ◽  
D. F. Paul ◽  
J. S. Hammond ◽  
K. D. Bomben

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.


1990 ◽  
Vol 185 ◽  
Author(s):  
Alain E. Kaloyeros ◽  
Robert M. Ehrenreich

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.


1994 ◽  
Vol 363 ◽  
Author(s):  
Y. W. Bae ◽  
W. Y. Lee ◽  
T. M. Besmann ◽  
P. J. Blau ◽  
K. L. More ◽  
...  

AbstractComposite coatings consisting of discrete phases of TiN and MoS2 were codeposited on graphite substrates from Ti((CH3)2N)4/NH3/MoF6/H2S gas mixtures in a cold-wall reactor at 1073 K and 1.3 kPa. Chemical composition and microstructure of the coatings were characterized by Auger electron spectroscopy, X-ray diffraction, and transmission electron microscopy. Kinetic friction coefficients of the coatings were determined by a computer-controlled friction microprobe and values less than 0.2 were obtained with a type-440C stainless-steel counterface under ambient condition.


1992 ◽  
Vol 7 (10) ◽  
pp. 2765-2773 ◽  
Author(s):  
T.C. Chou ◽  
T.G. Nieh ◽  
T.Y. Tsui ◽  
G.M. Pharr ◽  
W.C. Oliver

Artificial multilayers, or microlaminates, composed of alternating layers of Nb and MoSi2 of equal thickness were synthesized by d.c., magnetron sputtering. Four different modulation wavelengths, λ, were studied: 7, 11, 20, and 100 nm. The compositions, periodicities, and microstructures of the microlaminates were characterized by Auger electron spectroscopy and transmission electron microscopy. Structural characterization revealed that the as-deposited Nb layers are polycrystalline, while the MoSi2 layers are amorphous. The hardnesses and elastic moduli of the films were measured using nanoindentation techniques. Neither a supermodulus nor a superhardness effect could be identified in the range of wavelengths investigated; for each of the microlaminates, both the hardness and modulus were found to fall between the bounds set by the properties of the monolithic Nb and MoSi2 films. Nevertheless, a modest but a measurable increase in both hardness and modulus with decreasing wavelength was observed, thus indicating that behavior cannot be entirely described by a simple rule-of-mixtures. The hardness was found to vary linearly with Δ−1/2 in a manner similar to the Hall–Petch relationship. Annealing the microlaminates at 800 °C for 90 min produces significant increases in hardness and modulus due to chemical interaction of the layers.


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