Spatially varying chemical phase formation on silicon nano ripple by low energy mixed ions bombardment

Author(s):  
Joy Mukherjee ◽  
Dipak Bhowmik ◽  
Gaurab Bhattacharjee ◽  
Biswarup Satpati ◽  
Prasanta Karmakar

Abstract We report mixed (CO+ and N2+) ion beam induced spatially varying chemical phases formation on Si (100) surface in nanometer length scale. Simultaneous bombardment of carbon, oxygen and nitrogen like three reactive ions leads to well-defined ripple development and spatially varying periodic chemical phases formation. Post bombardment chemical changes of Si surface are investigated by X-ray Photoelectron Spectroscopy (XPS), and spatially resolved periodic variation of chemical phases are confirmed by Electron Energy Loss Spectroscopy (EELS). The thickness of ion modified amorphous layer, estimated by Monte Carlo Simulation (SRIM), is in excellent agreement with the cross-sectional Transmission Electron Microscopy measurements. The formation of such periodic nanoscale ripple having multiple chemical phases at different parts is explained in terms of chemical instability, local ion flux variation and difference in sputtering yield. Potential applications of such newly developed nano material are also addressed.

Author(s):  
D. L. Callahan ◽  
Z. Ball ◽  
H. M. Phillips ◽  
R. Sauerbrey

Ultraviolet laser-irradiation can be used to induce an insulator-to-conductor phase transition on the surface of Kapton polyimide. Such structures have potential applications as resistors or conductors for VLSI applications as well as general utility electrodes. Although the percolative nature of the phase transformation has been well-established, there has been little definitive work on the mechanism or extent of transformation. In particular, there has been considerable debate about whether or not the transition is primarily photothermal in nature, as we propose, or photochemical. In this study, cross-sectional optical microscopy and transmission electron microscopy are utilized to characterize the nature of microstructural changes associated with the laser-induced pyrolysis of polyimide.Laser-modified polyimide samples initially 12 μm thick were prepared in cross-section by standard ultramicrotomy. Resulting contraction in parallel to the film surface has led to distortions in apparent magnification. The scale bars shown are calibrated for the direction normal to the film surface only.


Author(s):  
A.E.M. De Veirman ◽  
F.J.G. Hakkens ◽  
W.M.J. Coene ◽  
F.J.A. den Broeder

There is currently great interest in magnetic multilayer (ML) thin films (see e.g.), because they display some interesting magnetic properties. Co/Pd and Co/Au ML systems exhibit perpendicular magnetic anisotropy below certain Co layer thicknesses, which makes them candidates for applications in the field of magneto-optical recording. It has been found that the magnetic anisotropy of a particular system strongly depends on the preparation method (vapour deposition, sputtering, ion beam sputtering) as well as on the substrate, underlayer and deposition temperature. In order to get a better understanding of the correlation between microstructure and properties a thorough cross-sectional transmission electron microscopy (XTEM) study of vapour deposited Co/Pd and Co/Au (111) MLs was undertaken (for more detailed results see ref.).The Co/Pd films (with fixed Pd thickness of 2.2 nm) were deposited on mica substrates at substrate temperatures Ts of 20°C and 200°C, after prior deposition of a 100 nm Pd underlayer at 450°C.


1991 ◽  
Vol 223 ◽  
Author(s):  
Qin Fuguang ◽  
Yao Zhenyu ◽  
Ren Zhizhang ◽  
S.-T. Lee ◽  
I. Bello ◽  
...  

ABSTRACTDirect ion beam deposition of carbon films on silicon in the ion energy range of 15–500eV and temperature range of 25–800°C has been studied using mass selected C+ ions under ultrahigh vacuum. The films were characterized with X-ray photoelectron spectroscopy, Raman spectroscopy, and transmission electron microscopy and diffraction analysis. Films deposited at room temperature consist mainly of amorphous carbon. Deposition at a higher temperature, or post-implantation annealing leads to formation of microcrystalline graphite. A deposition temperature above 800°C favors the formation of microcrystalline graphite with a preferred orientation in the (0001) direction. No evidence of diamond formation was observed in these films.


Author(s):  
Ching Shan Sung ◽  
Hsiu Ting Lee ◽  
Jian Shing Luo

Abstract Transmission electron microscopy (TEM) plays an important role in the structural analysis and characterization of materials for process evaluation and failure analysis in the integrated circuit (IC) industry as device shrinkage continues. It is well known that a high quality TEM sample is one of the keys which enables to facilitate successful TEM analysis. This paper demonstrates a few examples to show the tricks on positioning, protection deposition, sample dicing, and focused ion beam milling of the TEM sample preparation for advanced DRAMs. The micro-structures of the devices and samples architectures were observed by using cross sectional transmission electron microscopy, scanning electron microscopy, and optical microscopy. Following these tricks can help readers to prepare TEM samples with higher quality and efficiency.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Yan Ye ◽  
Da Yin ◽  
Bin Wang ◽  
Qingwen Zhang

We report the synthesis of three-dimensional Fe3O4/graphene aerogels (GAs) and their application for the removal of arsenic (As) ions from water. The morphology and properties of Fe3O4/GAs have been characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and superconducting quantum inference device. The 3D nanostructure shows that iron oxide nanoparticles are decorated on graphene with an interconnected network structure. It is found that Fe3O4/GAs own a capacity of As(V) ions adsorption up to 40.048 mg/g due to their remarkable 3D structure and existence of magnetic Fe3O4nanoparticles for separation. The adsorption isotherm matches well with the Langmuir model and kinetic analysis suggests that the adsorption process is pseudo-second-ordered. In addition to the excellent adsorption capability, Fe3O4/GAs can be easily and effectively separated from water, indicating potential applications in water treatment.


2000 ◽  
Vol 6 (S2) ◽  
pp. 530-531
Author(s):  
M.G. Burke ◽  
P.T. Duda ◽  
G. Botton ◽  
M. W. Phaneuf

Focused Ion Beam (FIB) micromachining techniques have gained significant attention over the past few years as a promising method for the preparation of a variety of metallic and nonmetallic materials for subsequent characterization using transmission electron microscopy (TEM) The advantage of the FIB in terms of site specificity and speed for the preparation of uniform electron transparent sections has opened a wide range of potential applications in materials characterization. The ability to image the sample in the FIB can also provide important microstructural data for materials analysis. In this study, both conventionally electropolished and FIB-ed specimens were prepared in order to characterize the microstructure of a commercially-produced tube of Alloy 600 (approximately Ni-15 Cr-10 Fe- 0.05 C). The electropolished samples were prepared using a solution of 20% HClO4 - 80% CH3OH at ∼-40°C. The FIB sections were obtained from a cross-section of the tube that had been mechanically thinned to ∼100 μm. The section was thinned in a Micrion 2500 FIB system with a Ga ion beam at 50 kV accelerating voltage.


Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5798
Author(s):  
Bingliang Liang ◽  
Yunlong Ai ◽  
Yiliang Wang ◽  
Changhong Liu ◽  
Sheng Ouyang ◽  
...  

High-entropy oxides (HEOs) have attracted more and more attention because of their unique structures and potential applications. In this work, (FeCoCrMnZn)3O4 HEO powders were synthesized via a facile solid-state reaction route. The confirmation of phase composition, the observation of microstructure, and the analysis of crystal structure, distribution of elements, and valences of elements were conducted by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS), respectively. Furthermore, a (FeCoCrMnZn)3O4/nickel foam ((FeCoCrMnZn)3O4/NF) electrode was prepared via a coating method, followed by the investigation of its supercapacitor performance. The results show that, after calcining (FeCoCrMnZn)3O4 powders at 900 °C for 2 h, a single spinel structure (FCC, Fd-3m, a = 0.8399 nm) was obtained with uniform distribution of Fe, Co, Cr, Mn, and Zn elements, the typical characteristic of a high-entropy oxide. In addition, the mass specific capacitance of the (FeCoCrMnZn)3O4/NF composite electrode was 340.3 F·g−1 (with 1 M KOH as the electrolyte and 1 A·g−1 current density), which indicates that the (FeCoCrMnZn)3O4 HEO can be regarded as a prospective candidate for an electrode material in the field of supercapacitor applications.


2002 ◽  
Vol 750 ◽  
Author(s):  
P. K. Sahoo ◽  
B. Satpati ◽  
S. Dey ◽  
P. V. Satyam ◽  
T. Som ◽  
...  

ABSTRACTIn the present work we have studied efficacy of ion beam induced epitaxial crystallization (IBIEC) to recover amorphous layers (300 – 350 nm) produced by MeV Kr ions in Si(100) and studied the associated changes occurring on surface and interface of the recrystallized region. IBIEC experiments were carried out at sample temperatures in the range of 200 − 400°C using 1 MeV N+ ion beam. Rutherford backscattering-Channeling technique showed planar and gradual recovery of the amorphous layer as a function of temperature. Transmission electron microscopy measurements show good crystalline structure of the recovered region at 400°C while at lower temperatures nano-crystalline Si formation embedded in the amorphous structure is evident. The surface topography studied by atomic force microscopy shows development of islands after IBIEC. The rms roughness is around 0.5 nm and average height of the islands is found to be 1.8 nm. The observed epitaxial growth and the surface topographical features have been correlated.


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