Surface evolution of strained SrRuO3 films deposited at various temperatures on SrTiO3 (001) substrates

2006 ◽  
Vol 21 (6) ◽  
pp. 1550-1560 ◽  
Author(s):  
Sang Ho Oh ◽  
Chan Gyung Park
Keyword(s):  
Epitaxial Growth ◽  
Ion Beam ◽  
Strain Relaxation ◽  
Scanning Tunneling ◽  
Misfit Dislocations ◽  
Ion Beam Sputtering ◽  
Ambient Conditions ◽  
Tunneling Microscopy ◽  
Surface Evolution ◽  
Relaxation Stage

Surface evolution was studied for strained SrRuO3 films with a nominal 75 nm thickness deposited at various substrate temperatures (650–850 °C). Epitaxial growth of the films was achieved on single TiO2-terminated SrTiO3 (001) substrates by using ion-beam sputtering. The surface morphology of the deposited films was investigated by scanning tunneling microscopy in ambient conditions, and their microstructure was characterized by transmission electron microscopy. The self-organized step-terrace structure was observed for the films deposited at lower than 800 °C, suggesting that the epitaxial growth proceeded by step-flow growth. In particular, each film showed characteristic surface evolutions pertinent to the misfit strain relaxation stage, mostly influenced by the moving segment of misfit dislocations threading up to the surface: surface undulations for the film at the initial stage of relaxation (deposited at 650 °C), circular growth spirals during the relaxation stage (700 °C), and well-ordered step-terrace structure after almost full development of misfit dislocations (750 and 800 °C).

Correlative STM, FESEM, and TEM studies of fibrillar structures in liquid crystalline polymers

1990 ◽  
Vol 48 (4) ◽  
pp. 866-867 ◽  
Author(s):  
I. H. Musselman ◽  
P.E. Russell ◽  
R.T. Chen ◽  
M.G. Jamieson ◽  
L.C. Sawyer
Keyword(s):  
Liquid Crystalline ◽  
Structural Model ◽  
Imaging Techniques ◽  
Ion Beam ◽  
Crystalline Polymer ◽  
Sample Surface ◽  
Scanning Tunneling ◽  
Ion Beam Sputtering ◽  
Tunneling Microscopy ◽  
Beam Sputtering

Hierarchical fibrillar structures have been reported to be present in liquid crystalline polymer (LCP) extrudates such as fibers and tapes. Using conventional scanning and transmission electron microscopy (SEM, TEM), the smallest fibrils were shown to be about 50 nm wide and 5 nm thick. With the emergence of higher resolution imaging techniques such as scanning tunneling microscopy (STM) and field emission SEM (FESEM), we have been able to further explore the ultrastructures in the LCP fibrils and extend the LCP structural model.The LCP materials investigated consist of copolyesters of 4-hydroxybenzoic acid (HBA) and 2- hydroxy-6-napthoic acid (HNA) in the form of melt-spun fibers and extruded tapes. These materials exhibit unidirectionally-oriented structures as revealed by x-ray diffraction and microscopy studies. For STM and FESEM, samples were prepared by a peel-back method which reveals the internal structures of fibrils. In addition, ultrasonication was used to disintegrate the LCP fibers and tapes to provide fine “fibrillar” samples for STM, FESEM, and TEM studies. The original tape and fiber surfaces were also examined by STM and FESEM. Thin Pt coatings (ca. 5 nm) were deposited on the LCP samples using ion beam sputtering to provide a conducting surface for STM and FESEM imaging. These coatings have been shown to introduce minimal topography to the original sample surface.

Evolution of Stress and Relaxation of Strain of Ge and SiGe Alloy Films on Si(001)

2001 ◽  
Vol 696 ◽  
Author(s):  
R. Koch ◽  
J. J. Schulz ◽  
B. Wassermann ◽  
G. Wedler
Keyword(s):  
Strain Relaxation ◽  
Misfit Strain ◽  
Growth Mode ◽  
Ex Situ ◽  
Scanning Tunneling ◽  
Misfit Dislocations ◽  
Tunneling Microscopy ◽  
Structural Investigations ◽  
Alloy Films ◽  
Sige Alloy

AbstractWe report on real time stress measurements by a sensitive cantilever beam technique of Ge and SiGe Alloy Films on Si(001) in combination with structural investigations by in situ STM (scanning tunneling microscopy) and ex situ AFM (atomic force microscopy). Characteristic features in the stress curves provide detailed insight into the development and relief of the misfit strain as well as the respective growth mode. For the Stranski-Krastanow system Ge/Si(001) the strain relaxation proceeds mainly in two steps: (i) by the formation of 3D islands on top of the Ge wetting layer and (ii) via misfit dislocations in larger 3D islands and upon their percolation. Co-deposition of Si influences the stress behavior drastically. The growth mode changes from Stranski-Krastanow to a kinetic 3D island mode at Si concentrations of about 20% leading to the so far smallest quantum dots of the Ge/Si system.

Direct Observations of the Epitaxial Growth of Sputtered Ag on Si

1973 ◽  
Vol 31 ◽  
pp. 122-123
Author(s):  
J. S. Maa ◽  
Thos. E. Hutchinson
Keyword(s):  
Epitaxial Growth ◽  
Film Growth ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
Microscopy Technique ◽  
Direct Observations ◽  
In Situ Electron Microscopy ◽  
Beam Sputtering ◽  
The Subject

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.

Atomic force microscopy (AFM) of the topography of silicon surfaces exposed to ion beams

1992 ◽  
Vol 50 (2) ◽  
pp. 1132-1133
Author(s):  
Mark Denker ◽  
Jennifer Wall ◽  
Mark Ray ◽  
Richard Linton
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Incidence Angle ◽  
Ion Beam ◽  
Depth Profiling ◽  
Depth Resolution ◽  
Ion Beams ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Trace Impurities ◽  
Energy Dose

Reactive ion beams such as O2+ and Cs+ are used in Secondary Ion Mass Spectrometry (SIMS) to analyze solids for trace impurities. Primary beam properties such as energy, dose, and incidence angle can be systematically varied to optimize depth resolution versus sensitivity tradeoffs for a given SIMS depth profiling application. However, it is generally observed that the sputtering process causes surface roughening, typically represented by nanometer-sized features such as cones, pits, pyramids, and ripples. A roughened surface will degrade the depth resolution of the SIMS data. The purpose of this study is to examine the relationship of the roughness of the surface to the primary ion beam energy, dose, and incidence angle. AFM offers the ability to quantitatively probe this surface roughness. For the initial investigations, the sample chosen was <100> silicon, and the ion beam was O2+.Work to date by other researchers typically employed Scanning Tunneling Microscopy (STM) to probe the surface topography.

scholarly journals Charged particle single nanometre manufacturing

2018 ◽  
Vol 9 ◽  
pp. 2855-2882 ◽  
Author(s):  
Philip D Prewett ◽  
Cornelis W Hagen ◽  
Claudia Lenk ◽  
Steve Lenk ◽  
Marcus Kaestner ◽  
...  
Keyword(s):  
Charged Particle ◽  
High Throughput ◽  
Nanoimprint Lithography ◽  
Ion Beam ◽  
Ambient Air ◽  
Particle Beam ◽  
Vacuum System ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Charged Particle Beam

Following a brief historical summary of the way in which electron beam lithography developed out of the scanning electron microscope, three state-of-the-art charged-particle beam nanopatterning technologies are considered. All three have been the subject of a recently completed European Union Project entitled “Single Nanometre Manufacturing: Beyond CMOS”. Scanning helium ion beam lithography has the advantages of virtually zero proximity effect, nanoscale patterning capability and high sensitivity in combination with a novel fullerene resist based on the sub-nanometre C60 molecule. The shot noise-limited minimum linewidth achieved to date is 6 nm. The second technology, focused electron induced processing (FEBIP), uses a nozzle-dispensed precursor gas either to etch or to deposit patterns on the nanometre scale without the need for resist. The process has potential for high throughput enhancement using multiple electron beams and a system employing up to 196 beams is under development based on a commercial SEM platform. Among its potential applications is the manufacture of templates for nanoimprint lithography, NIL. This is also a target application for the third and final charged particle technology, viz. field emission electron scanning probe lithography, FE-eSPL. This has been developed out of scanning tunneling microscopy using lower-energy electrons (tens of electronvolts rather than the tens of kiloelectronvolts of the other techniques). It has the considerable advantage of being employed without the need for a vacuum system, in ambient air and is capable of sub-10 nm patterning using either developable resists or a self-developing mode applicable for many polymeric resists, which is preferred. Like FEBIP it is potentially capable of massive parallelization for applications requiring high throughput.

COMBINED HRLEED AND STM INVESTIGATIONS ON THE INITIAL STAGES OF Cu HETEROEPITAXY Ru(0001)

1997 ◽  
Vol 04 (06) ◽  
pp. 1167-1171 ◽  
Author(s):  
CH. AMMER ◽  
K. MEINEL ◽  
H. WOLTER ◽  
A. BECKMANN ◽  
H. NEDDERMEYER
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Strain Relaxation ◽  
Local Scale ◽  
Low Energy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Low Energy Electron Diffraction ◽  
Layer Structures ◽  
Low Energy Electron

Recent scanning tunneling microscopy (STM) observations revealed different layer structures in the heteroepitaxial Cu/Ru(0001) system with increasing film thickness attributed to various stages of strain relaxation. High-resolution low-energy electron diffraction (HRLEED) analysis permits one to derive more exactly both lattice periodicities and lattice rotations. Furthermore, the representative character of local STM results can be proved. However, STM measurements are needed to identify and to assign the satellite spots to coexistent different superstructures which are superposed incoherently in the diffraction pattern. Generally, the integral LEED results confirm the crystallographic data obtained by STM in a local scale.

Study of Epitaxial Growth of Au on Ni(110) by Scanning Tunneling Microscopy

1987 ◽  
Vol 94 ◽  
Author(s):  
Y. Kuk ◽  
P. J. Silverman ◽  
T. M. Buck
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Epitaxial Growth ◽  
Scanning Tunneling ◽  
Tunneling Microscopy

ABSTRACTThe structure of the Au segregated Ni(110)-0.8%Au surface has been studied by scanning tunneling microscopy. The segregated Au layer forms a (7×4) structure with a c(2×4) subunit. At various coverages of Au overlayer, commensurate and incommensurate Au structures were observed. At a coverage of I monolayer, islands and facets assciated with incommensurate Au atoms were observed.

scholarly journals Epitaxial growth by monolayer restricted galvanic displacement

2012 ◽  
Vol 77 (9) ◽  
pp. 1239-1242
Author(s):  
Rastko Vasilic
Keyword(s):  
Epitaxial Growth ◽  
Deposition Process ◽  
Scanning Tunneling ◽  
Deposit Morphology ◽  
Galvanic Displacement ◽  
Tunneling Microscopy ◽  
Efficient Tool ◽  
Dimensional Growth ◽  
Key Parameter

The development of a new method for epitaxial growth of metals in solution by galvanic displacement of layers pre-deposited by underpotential deposition (UPD) was discussed and experimentally illustrated throughout the lecture. Cyclic voltammetry (CV) and scanning tunneling microscopy (STM) are employed to carry out and monitor a ?quasi-perfect?, two-dimensional growth of Ag on Au(111), Cu on Ag(111), and Cu on Au(111) by repetitive galvanic displacement of underpotentially deposited monolayers. A comparative study emphasizes the displacement stoichiometry as an efficient tool for thickness control during the deposition process and as a key parameter that affects the deposit morphology. The excellent quality of layers deposited by monolayer-restricted galvanic displacement is manifested by a steady UPD voltammetry and ascertained by a flat and uniform surface morphology maintained during the entire growth process.

scholarly journals STM study on the self-assembly of oligothiophene-based organic semiconductors

2011 ◽  
Vol 2 ◽  
pp. 802-808 ◽  
Author(s):  
Elena Mena-Osteritz ◽  
Marta Urdanpilleta ◽  
Erwaa El-Hosseiny ◽  
Berndt Koslowski ◽  
Paul Ziemann ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Self Assembly ◽  
Theoretical Calculations ◽  
The Self ◽  
Scanning Tunneling ◽  
Ambient Conditions ◽  
Tunneling Microscopy ◽  
Substitution Pattern ◽  
Electronic Density ◽  
The Individual

The self-assembly properties of a series of functionalized regioregular oligo(3-alkylthiophenes) were investigated by using scanning tunneling microscopy (STM) at the liquid–solid interface under ambient conditions. The characteristics of the 2-D crystals formed on the (0001) plane of highly ordered pyrolitic graphite (HOPG) strongly depend on the length of the π-conjugated oligomer backbone, on the functional groups attached to it, and on the alkyl substitution pattern on the individual thiophene units. Theoretical calculations were performed to analyze the geometry and electronic density of the molecular orbitals as well as to analyze the intermolecular interactions, in order to obtain models of the 2-D molecular ordering on the substrate.

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