In situ scanning tunneling microscopy studies of the evolution of surface morphology and microstructure in epitaxial TiN(001) grown by ultra-high-vacuum reactive magnetron sputtering

1997 ◽  
Vol 94-95 ◽  
pp. 403-408 ◽  
Author(s):  
Brian W. Karr ◽  
I. Petrov ◽  
P. Desjardins ◽  
David G. Cahill ◽  
J.E. Greene
Keyword(s):  
Surface Morphology ◽  
Magnetron Sputtering ◽  
Scanning Tunneling Microscopy ◽  
High Vacuum ◽  
Reactive Magnetron Sputtering ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Reactive Magnetron ◽  
Tunneling Microscopy

Pulsed Laser Deposition and In Situ Scanning Tunneling Microscopy of Pd clusters supported on alumina

2011 ◽  
Vol 1351 ◽  
Author(s):  
C.S. Casari ◽  
S. Foglio ◽  
M. Corbetta ◽  
M. Passoni ◽  
C.E. Bottani ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Pulsed Laser Deposition ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Ultra High Vacuum ◽  
Laser Deposition ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Pd Clusters

ABSTRACTWith the aim of addressing the material gap issue between model and real systems in heterogeneous catalysis, we exploited Pulsed Laser Deposition (PLD) to produce Pd clusters supported on ultrathin alumina films (Pd/Al2O3/NiAl(001) and Pd/Al2O3-x/HOPG). The structural properties have been investigated by in situ Scanning Tunneling Microscopy (STM) in ultra high vacuum (UHV). At first, Pd clusters were deposited by evaporation and by PLD on Al2O3 surfaces grown by thermal oxidation of NiAl(001). The system shows thermal stability up to 650 K. By PLD we deposited Pd clusters with a good size control obtained by varying the background gas pressure and the target-to-substrate distance. We then realized aPd/Al2O3-x/HOPG system where both Pd clusters and the alumina film are produced by PLD showing that, by exploiting the same deposition technique, it is possible to synthesize both a model system addressable by in situ STM and a thick film (∼100 μm) closer to realistic systems.

Using a Moderate Vacuum, Hot/Cryo-Stage Equipped AFM for In-Situ Observation of α-Phase Growth In 60SN40PB Hypoeutectic Solder

1998 ◽  
Vol 4 (S2) ◽  
pp. 316-317
Author(s):  
D. N. Leonard ◽  
P.E. Russell
Keyword(s):  
Surface Science ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
In Situ Observation ◽  
Atmospheric Conditions ◽  
Tunneling Microscopy ◽  
Wide Range ◽  
Gas Environment

Atomic force microscopy (AFM) was introduced in 1984, and proved to be more versatile than scanning tunneling microscopy (STM) due to the AFM's capabilities to scan non-conductive samples under atmospheric conditions and achieve atomic resolution. Ultra high vacuum (UHV) AFM has been used in surface science applications when control of oxidation and corrosion of a sample's surface are required. Expensive equipment and time consuming sample exchanges are two drawbacks of the UHV AFM system that limit its use. Until recently, no hot/cryo-stage, moderate vacuum, controlled gas environment AFM was commonly available.We have demonstrated that phase transformations are easily observable in metal alloys and polymers with the use of a moderate vacuum AFM that has in-situ heating/cooling capabilities and quick (within minutes) sample exchange times. This talk will describe the results of experiments involving a wide range of samples designed to make use of the full capabilities of a hot/cryo-stage, controlled gas environment AFM.

Scanning Tunneling Microscopy Observation Of Single Dangling Bonds on the Si(100)2×1:H Surface

2001 ◽  
Vol 705 ◽  
Author(s):  
Lequn Liu ◽  
Jixin Yu ◽  
Joseph W. Lyding
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Negative Charge ◽  
High Vacuum ◽  
Surface Current ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Dangling Bonds ◽  
Tunneling Microscopy ◽  
Current Image ◽  
P Type

AbstractThe electrical properties of single dangling bonds on the Si(100)2×1:H surface are investigated by ultra high vacuum scanning tunneling microscopy. On the N-type Si(100)2×1:H surface, single dangling bonds created by feedback controlled lithography and natural dangling bonds have a fixed negative charge. On the other hand, they are observed as neutral on the P-type Si(100)2×1:H surface. Current image tunneling spectroscopy is used to characterize both types of dangling bonds. The dangling bonds with fixed negative charge display a dramatic voltage dependence with Friedel oscillations observed in the empty state images. The neutral dangling bonds appear as protrusions in both the empty and filled state images.

A Scanning Tunneling Microscopy Study: Si/SiO2 Interface Roughness Induced by Chemical Etching

2004 ◽  
Vol 838 ◽  
Author(s):  
Jixin Yu ◽  
Lequn Liu ◽  
Joseph W. Lyding
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Chemical Etching ◽  
High Vacuum ◽  
Microscopy Study ◽  
Interface Roughness ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Channel Mobility ◽  
Scanning Tunneling Microscopy Study

ABSTRACTThe Si/SiO2 interface roughness has received tremendous interest due to its relation to channel mobility degradation and dielectric reliability. We have used ultra-high vacuum scanning tunneling microscopy to directly examine the Si/SiO2 interface and study the roughening effect caused by chemical etching. The rms-roughness extracted quantitatively from the STM topography was found to be doubled from 0.111nm to 0.232nm by the normal NH4OH/H2O2 treatment, and further increased to 0.285nm for additional etching steps. It was also found that there were no regular single steps on the SiO2/Si(100) interface.

Ultra High Vacuum Scanning Tunneling Microscopy Observation of Multilayer Step Structure on GaAs and AlAs Vicinal Surface Grown by Metalorganic Vapor Phase Epitaxy

1996 ◽  
Vol 448 ◽  
Author(s):  
Jun-Ya Ishizaki ◽  
Yasuhiko Ishizaki ◽  
Takashi Fukui
Keyword(s):  
Scanning Tunneling Microscopy ◽  
High Vacuum ◽  
Gaas Layer ◽  
Layer Growth ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Vicinal Surface ◽  
Microscopy Observation ◽  
Tunneling Microscopy ◽  
Atomic Structures

AbstractWe observe the atomic structures at the multilayer step region on MOVPE-grown GaAs (001) vicinal surface using ultra high vacuum scanning tunneling microscopy (UHV-STM), and clarify that (4×2) or (4×3) like reconstruction units are dominant. Oxide free AlAs surfaces grown on GaAs vicinal surface are also successfully observed by UHV-STM. The reconstruction units at the multilayer step region on AlAs surface have the same units on GaAs vicinal surface. GaAs surface has the lack of dimmer rows on the terrace region just below the multilayer step region, while AlAs surface has dimmer rows even on the terrace just below the multilayer step region. GaAs layer growth leads tothe step bunching phenomenon and AlAs surface leads to the step debunching phenomenon.

Stress-induced structures on surfaces observed using Scanning Tunneling Microscopy and low-energy Electron Microscopy

1992 ◽  
Vol 50 (1) ◽  
pp. 332-333
Author(s):  
Ellen D. Williams ◽  
R.J. Phaneuf ◽  
N.C. Bartelt ◽  
W. Swiech ◽  
E. Bauer
Keyword(s):  
Electron Microscopy ◽  
Surface Morphology ◽  
Scanning Tunneling Microscopy ◽  
High Vacuum ◽  
Finite Size ◽  
Low Energy ◽  
Energy Electron ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Low Energy Electron

Elastic stresses play a well-known and important role in the structure of thin films during growth. However, elastic effects can also greatly influence surface morphology of the substrate. One source of this influence, as has long been recognized is the elastic interactions between steps on surfaces. More recently, Marchenko has shown that surface stress can stabilize finite-size structures in surfaces, such as facets. Traditionally surface morphologies such as steps and facets have been measured by low-energy electron diffraction. However, the more recent development of ultra-high vacuum compatible microscopic techniques such as scanning tunneling microscopy, reflection electron microscopy, and low-energy electron microscopy, now make it possible to image steps and facets directly to obtain information about sizes and size distributions. This information in turn makes it possible to test the influence of stress on surface morphology directly.

IN SITU STM INVESTIGATION OF Ge NANOSTRUCTURES WITH AND WITHOUT Sb ON GRAPHITE

2006 ◽  
Vol 13 (02n03) ◽  
pp. 241-249
Author(s):  
SUNIL SINGH KUSHVAHA ◽  
ZHIJUN YAN ◽  
MAO-JIE XU ◽  
WENDE XIAO ◽  
XUE-SEN WANG
Keyword(s):  
Room Temperature ◽  
Pyrolytic Graphite ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Initial Stage ◽  
Defect Sites ◽  
Substrate Defects

Germanium was deposited onto highly oriented pyrolytic graphite (HOPG) with and without antimony in ultra-high vacuum. The surface morphology was analyzed using in situ scanning tunneling microscopy (STM) at room temperature (RT). The film grows exclusively in 3D island mode and was affected significantly by substrate defects. At initial stage, nucleation of cluster occurred at step edges and defect sites. Later, we found various types of Ge nanostructures on HOPG in different deposition conditions and stages, including cluster chains, cluster islands, nanowires, and double layer ramified islands at RT. Compact Ge islands were observed when depositing at a substrate temperature of 450 K or after an annealing at 600 K following RT deposition. In addition, the pre-deposited Sb on graphite enhances the sticking probability and suppresses the surface diffusion of Ge atoms, resulting in a significant increase in Ge cluster island density on HOPG terraces.

Sign in / Sign up

Export Citation Format

Share Document