scholarly journals Structure and morphology of nano-sized W-Ti/Si thin films

2006 ◽  
Vol 71 (8-9) ◽  
pp. 969-976 ◽  
Author(s):  
Suzana Petrovic ◽  
Borivoje Adnadjevic ◽  
Davor Perusko ◽  
Nada Popovic ◽  
Nenad Bundaleski ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Roughness ◽  
Grain Size ◽  
Phase Composition ◽  
Surface Segregation ◽  
Morphological Characteristics ◽  
Film Surface ◽  
Scanning Tunneling ◽  
Tunneling Microscopy

Thin films were deposited by d.c. sputtering onto a silicon substrate. The influence of the W-Ti thin film thickness to its structural and morphological characteristics of a nano-scale were studied. The phase composition and grain size were studied by X-ray diffraction (XRD), while the surface morphology and surface roughness were determined by scanning tunneling microscopy (STM). The analysis of the phase composition show that the thin films had a polycrystalline structure - they were composed of a b.c.c. W phase with the presence of a h.c.p. Ti phase. The XRD peak in the scattering angle interval of 38?-43? was interpreted as an overlap of peaks corresponding to the W(110) and Ti(101) planes. The grain size and the mean surface roughness both increase with the thikness of the thin film. The chemical composition of the thin film surface was also analyzed by low energy ions scattering (LEIS). The results show the surface segregation of titanium, as well as a substantial presence of oxygen an the surface.

Scanning Tunneling Microscopy and Atomic Force Microscopy Investigation of Organic Tetracyanoquinodimethane Thin Films

1997 ◽  
Vol 12 (8) ◽  
pp. 1942-1945 ◽  
Author(s):  
H. J. Gao ◽  
H. X. Zhang ◽  
Z. Q. Xue ◽  
S. J. Pang
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Scanning Tunneling Microscopy ◽  
Pyrolytic Graphite ◽  
Film Surface ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Investigation

Scanning tunneling microscopy (STM) and atomic force microscopy (AFM) investigation of tetracyanoquinodimethane (TCNQ) and the related C60-TCNQ thin films is presented. Periodic molecular chains of the TCNQ on highly oriented pyrolytic graphite (HOPG) substrates were imaged, which demonstrated that the crystalline (001) plane was parallel to the substrate. For the C60-TCNQ thin films, we found that there were grains on the film surface. STM images within the grain revealed that the well-ordered rows and terraces, and the parallel rows in different grains were generally not in the same orientation. Moreover, the grain boundary was also observed. In addition, AFM was employed to modify the organic TCNQ film surface for the application of this type of materials to information recording and storage at the nanometer scale. The nanometer holes were successfully created on the TCNQ thin film by the AFM.

scholarly journals Etching Characteristics and Changes in Surface Properties of IGZO Thin Films by O2 Addition in CF4/Ar Plasma

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 906
Author(s):  
Chea-Young Lee ◽  
Young-Hee Joo ◽  
Minsoo P. Kim ◽  
Doo-Seung Um ◽  
Chang-Il Kim
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Roughness ◽  
Work Function ◽  
Surface Properties ◽  
Plasma Etching ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Film Surface ◽  
Etching Mechanism

Plasma etching processes for multi-atomic oxide thin films have become increasingly important owing to the excellent material properties of such thin films, which can potentially be employed in next-generation displays. To fabricate high-performance and reproducible devices, the etching mechanism and surface properties must be understood. In this study, we investigated the etching characteristics and changes in the surface properties of InGaZnO4 (IGZO) thin films with the addition of O2 gases based on a CF4/Ar high-density-plasma system. A maximum etch rate of 32.7 nm/min for an IGZO thin film was achieved at an O2/CF4/Ar (=20:25:75 sccm) ratio. The etching mechanism was interpreted in detail through plasma analysis via optical emission spectroscopy and surface analysis via X-ray photoelectron microscopy. To determine the performance variation according to the alteration in the surface composition of the IGZO thin films, we investigated the changes in the work function, surface energy, and surface roughness through ultraviolet photoelectron spectroscopy, contact angle measurement, and atomic force microscopy, respectively. After the plasma etching process, the change in work function was up to 280 meV, the thin film surface became slightly hydrophilic, and the surface roughness slightly decreased. This work suggests that plasma etching causes various changes in thin-film surfaces, which affects device performance.

Molecular Dynamics Simulation of Aluminium Thin Film Surface Activated Bonding

2011 ◽  
Vol 486 ◽  
pp. 127-130
Author(s):  
Chao Cheng Chang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Molecular Dynamics ◽  
Surface Roughness ◽  
Bonding Strength ◽  
Film Surface ◽  
Dynamics Simulation ◽  
Thin Film Surface ◽  
Common Neighbour ◽  
Eam Potential

This study used molecular dynamics simulations with an embedded-atom method (EAM) potential to investigate the effect of surface roughness on the surface activated bonding (SAB) of aluminium thin films. The simulations started with the bonding process and followed by the tensile test for estimating bonding strength. By averaging the atomic stresses over the entire system, the stress-time curves for the bonded films under a tensile condition were predicted. Moreover, the evolution of the crystal structure in the local atomic order was examined by the common neighbour analysis. The simulated results show that the decrease in the surface roughness of thin film improves the bonding strength. The observed recrystallization processes inside the bonded thin films also reveal that the plastic deformation of the aluminium surface due to atomic attracting force compensates surface roughness.

Structural characterization of conducting polymer thin films using scanned probe microscopies

1992 ◽  
Vol 50 (2) ◽  
pp. 1136-1137
Author(s):  
I. H. Musselman ◽  
K. H. Gray ◽  
R. M. Leasure ◽  
T. J. Meyer ◽  
R. W. Linton
Keyword(s):  
Thin Films ◽  
Conducting Polymer ◽  
Secondary Ion Mass Spectrometry ◽  
Pyrolytic Graphite ◽  
Polymer Thin Films ◽  
Film Surface ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Storage Devices ◽  
Control Film

As alternatives to silicon-based devices, organometallic conducting polymer thin-films are being used to develop new applications involving electrocatalysis, sensors, optical storage devices, and electrochromic displays. The chemical and topographic homogeneity of these films may play an important role in their electrochemical properties, as well as in their ability to form array structures with high spatial control. Film microstructures can be revealed using a range of surface specific characterization techniques. In our laboratory, scanning tunneling microscopy (STM) and atomic force microscopy (AFM) have been used to assess the surface structure (roughness and thickness) of these films. Results of the scanned probe microscopies also provide insight into the effects of initial film surface roughness and chemical microhomogeneity on the sputter depth profiles obtained using secondary ion mass spectrometry (SIMS). Reductive electropolymerization techniques were used to prepare separate thin polymeric films on B-doped highly oriented pyrolytic graphite (HOPG) substrates from monomer solutions of [Ru(Me4bpy)2(vpy)2]2+ (Me4bpy is 4, 4', 5, 5' - tetramethyl - 2, 2' bipyridine, vpy is 4 - vinylpyridine) and [Fe((CH2Br)2bpy)3]2+ ((CH2Br)2bpy is 4, 4' - dibromomethyl - 2, 2' - bipyridine).

Nanoscale Etching of Metallic Perovskites Using STM

2004 ◽  
Vol 811 ◽  
Author(s):  
Ø. Dahl ◽  
S. Hallsteinsen ◽  
J. K. Grepstad ◽  
A. Borg ◽  
T. Tybell
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Structure ◽  
Scanning Tunneling Microscope ◽  
Film Surface ◽  
Scanning Tunneling ◽  
Nanometer Scale ◽  
Tunneling Microscope ◽  
Unit Cells

ABSTRACTIn the present work we use a scanning tunneling microscope to modify the surface structure of epitaxial SrRuO3 thin films. Point and line etching experiments were carried out in ultra-highvacuum, using tungsten tips. The point etchings showed that pulses fired at small (< 4.5V) bias voltages did not bring about any physical modifications of the film surface, while voltages in excess of4.5 V led to etched holes accompanied by mounds. Moreover, well-defined line etching was achieved with atypical depth of approximately two unit cells and linewidths as small as 5 nm. The experiments demonstrate that a scanning tunneling microscope can be used for nanometer-scale patterning of SrRuO3 thin film surfaces.

Characteristics of conductive SrRuO3 thin films with different microstructures

1996 ◽  
Vol 11 (9) ◽  
pp. 2263-2268 ◽  
Author(s):  
Q. X. Jia ◽  
F. Chu ◽  
C. D. Adams ◽  
X. D. Wu ◽  
M. Hawley ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Deposition Temperature ◽  
Film Surface ◽  
Film Deposition ◽  
Degree Of Crystallinity ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Residual Resistivity Ratio ◽  
Resistivity Ratio

Conductive SrRuO3 thin films were epitaxially grown on (100) LaAlO3 substrates by pulsed laser deposition over a temperature range from 650 °C to 825 °C. Well-textured films exhibiting a strong orientation relationship to the underlying substrate could be obtained at a deposition temperature as low as 450 °C. The degree of crystallinity of the films improved with increasing deposition temperature as confirmed by x-ray diffraction, transmission electron microscopy, and scanning tunneling microscopy. Scanning electron microscopy revealed no particulates on the film surface. The resistivity of the SrRuO3 thin films was found to be a strong function of the crystallinity of the film and hence the substrate temperature during film deposition. A residual resistivity ratio (RRR = ρ300 K/ρ4.2 K) of more than 8 was obtained for the SrRuO3 thin films deposited under optimized processing conditions.

The influence of the internal microstructure on the surface parameters of polycrystalline thin films

2001 ◽  
Vol 672 ◽  
Author(s):  
C. Eisenmenger-Sittner ◽  
A. Bergauer
Keyword(s):  
Thin Films ◽  
Correlation Functions ◽  
Physical Vapor Deposition ◽  
Film Surface ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Glass Substrates ◽  
Topographic Data ◽  
Polycrystalline Thin Films ◽  
Power Spectral

ABSTRACTPhysical Vapor Deposition (PVD) processes commonly lead to the formation of polycrystalline thin films due to the effects of island nucleation and growth. Scanning probe Methods such as Atomic Force Microscopy (AFM) or Scanning Tunneling Microscopy (STM) are widely used for the characterization of the film surface. The topographic data obtained from these measurements can be converted to roughness values, Power Spectral Densities (PSD's) or correlation functions.It is the objective of this paper to evaluate the possibilities to characterize the polycrystalline template which generates the film surface solely by quantities derived from topographic data. For this purpose roughness values, PSD's and correlation functions of polycrystalline Al-Films deposited on glass substrates and from simulated surfaces are compared. The main factors which influence the shape of PSD's and correlation functions are determined and possible connections between the constitution of the polycrystalline template (e. g. shape and size-distribution of the crystalline domains) and the film roughness are discussed.

Pulsed Laser Deposition of Cluster-Assembled Thin Films with Controlled Nanostructure

2005 ◽  
Vol 901 ◽  
Author(s):  
Andrea Li Bassi ◽  
Carlo Spartaco Casari ◽  
Fabio Di Fonzo ◽  
Alessandro Bailini ◽  
Matteo Fusi ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Film Surface ◽  
Specific Area ◽  
Laser Deposition ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Compact Structure ◽  
Background Gas

AbstractThin films synthesized by assembling clusters present interesting chemical and physical properties and a large specific surface, and are appealing for functional applications (e.g. sensing and catalysis). Also, clusters supported on surfaces are interesting both for nanocatalysis applications and for fundamental research. By means of pulsed laser deposition (PLD) in a background atmosphere we can induce cluster aggregation in the ablation plume and control the deposition kinetic energy of the clusters. These phenomena depend on the plume expansion dynamics and their influence on the properties of the deposited films has been investigated as a function of the background gas mass and pressure. The control of these parameters permits variation of the film surface morphology, from a compact structure with a very smooth surface, to a film with a controlled roughness at the nanoscale, to an open, low density meso- and nanostructure characterized by a high fraction of voids and by a large specific area. Thin films of WOx, TiOx, Pd/PdO, and Ag were deposited and characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM) and Raman spectroscopy. Post-deposition annealing permits control of the crystalline degree of the films, which in the case of tungsten and titanium oxide is found to depend on the original nanostructure, while a different degree of oxidation can be induced by controlling the amount of oxygen in the deposition chamber. In-situ scanning tunneling microscopy (STM) was employed to study the first stages of growth of W films on different substrates. This opens the possibility to tailor the material properties through the control of the building nano-units.

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