Nanostructuring of Bi(0001) surfaces with the scanning tunneling microscope: Writing of periodic Bi structures by bias voltage pulsing

2005 ◽  
Vol 87 (17) ◽  
pp. 173103
Author(s):  
A. Turchanin ◽  
W. Freyland
Keyword(s):  
Bias Voltage ◽  
Scanning Tunneling Microscope ◽  
Scanning Tunneling ◽  
Tunneling Microscope

scholarly journals Lateral Manipulation of Single Adsorbates and Substrate Atoms With the Scanning Tunneling Microscope

MRS Bulletin ◽  
1998 ◽  
Vol 23 (1) ◽  
pp. 28-32 ◽  
Author(s):  
G. Meyer ◽  
K.H. Rieder
Keyword(s):  
Bias Voltage ◽  
Scanning Tunneling Microscope ◽  
Chemical Interaction ◽  
Translational Motion ◽  
Tunneling Current ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
Ambient Temperatures ◽  
Large Molecules

The stability and precision of modern scanning-tunneling-microscope (STM) systems allow positioning of the tip on a subnanometer scale. This advancement has stimulated diverse efforts on surface modifications in the nanometer and even atomic range, as recently reviewed by Avouris. The lateral movement of individual adatoms and molecules in a controlled manner on solid surfaces and the construction of structures on a nanoscale were first demonstrated by Eigler and collaborators at 4 K. The reason for operating the STM at low temperatures (apart from increased stability and sensitivity of the STM setup itself) is the necessity to freeze the motion of single adsorbates, which are very often mobile at ambient temperatures. By selecting strongly bonded adsorbate/substrate combinations and large molecules, it was possible to extend the lateral manipulation technique even to room temperature. In the case of large molecules, not only their translational motion but also internal flexure of the molecule during the positioning process must be considered. In general, different physical and chemical interaction mechanisms between tip and sample can be exploited for atomic-scale manipulation. We will concentrate in the following on lateral manipulation where solely the forces that act on the adsorbate because of the proximity of the tip are used. This means that long-range van der Waals and short-range chemical forces can be used to move atoms or molecules along the surface. No bias voltage or tunneling current is necessary. Apart from this technique, additional advances using the effects caused by the electric field generated by the bias voltage between tip and sample and by the current flowing through the gap region can be used for atomic or molecular modification.

Fabrication of Nanostructures of Low-Resistivity Silicon Wafer with High-Aspect-Ratio Using Carbon Nanotube Probe of Scanning Tunneling Microscope

2013 ◽  
Vol 1527 ◽  
Author(s):  
Akihito Matsumuro ◽  
Makoto Takagi
Keyword(s):  
Carbon Nanotube ◽  
Aspect Ratio ◽  
Silicon Wafer ◽  
Bias Voltage ◽  
High Aspect Ratio ◽  
Scanning Tunneling Microscope ◽  
Scanning Tunneling ◽  
Formation Mechanisms ◽  
Tunneling Microscope ◽  
Low Resistivity

ABSTRACTVarious nanostructures with high-aspect-ratio formed in a low-resistivity silicon wafer by the nano-processing using a carbon nanotube (CNT) probe of a scanning tunneling microscope (STM) have been investigated. The multi-wall CNT probes were obtained with our original pulling-method from CNT dispersion liquid. Nanostructures of point configurations (pit and mound) and line configurations were obtained at the constant tunneling current of 0.1 nA by controlling the bias voltages up to 10 V, processing times up to 300 s and scanning speeds of probe up to 480 nm/s for a line configuration. The aspect-ratio of the pit configuration fabricated at the bias voltage of 3 V increased about 6 times in proportion to the increase in processing time. Remarkable influence of the bias voltage on the configurations indicated that there exists a threshold bias voltage for the transition from the pit configuration to the mound one between 3 V and 5 V, and the aspect ratio of all nanostructures fabricated by the CNT probe were larger than those by a conventional tungsten probe. Finally, cross-sectional TEM observations were also applied to clarify the difference in the formation mechanisms between the pit configuration and the mound configuration. The TEM image of the pit configuration showed neither dislocations nor remarkable strains existed, but in the case of the mound shape TEM analysis indicated the existence of single crystalline silicon region solidified with atomic defects under the mound configuration. Therefore the drastic change of the configurations was attributed to the changes of the atomic-scale microstructures by applying the bias voltages.

Scanning tunneling microscopy of E. coli RNA polymerase deposited onto an Au substrate by an electrochemical process

1991 ◽  
Vol 49 ◽  
pp. 378-379
Author(s):  
Rebecca W. Keller ◽  
Carlos Bustamante ◽  
David Bear
Keyword(s):  
Scanning Tunneling Microscope ◽  
Biological Sample ◽  
Substrate Surface ◽  
Electrochemical Process ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Tunneling Microscope ◽  
E Coli ◽  
Preparation Techniques

Under ideal conditions, the Scanning Tunneling Microscope (STM) can create atomic resolution images of different kinds of samples. The STM can also be operated in a variety of non-vacuum environments. Because of its potentially high resolution and flexibility of operation, it is now being applied to image biological systems. Several groups have communicated the imaging of double and single stranded DNA.However, reproducibility is still the main problem with most STM results on biological samples. One source of irreproducibility is unreliable sample preparation techniques. Traditional deposition methods used in electron microscopy, such as glow discharge and spreading techniques, do not appear to work with STM. It seems that these techniques do not fix the biological sample strongly enough to the substrate surface. There is now evidence that there are strong forces between the STM tip and the sample and, unless the sample is strongly bound to the surface, it can be swept aside by the tip.

STM of freeze-fracture replicas: Problems and promises

1993 ◽  
Vol 51 ◽  
pp. 68-69
Author(s):  
J. T. Woodward ◽  
J. A. N. Zasadzinski
Keyword(s):  
Scanning Tunneling Microscope ◽  
Organic Materials ◽  
Freeze Fracture ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
Molecular Scale ◽  
Organic Surfaces ◽  
Metal Layers ◽  
Conductive Surfaces

The Scanning Tunneling Microscope (STM) offers exciting new ways of imaging surfaces of biological or organic materials with resolution to the sub-molecular scale. Rigid, conductive surfaces can readily be imaged with the STM with atomic resolution. Unfortunately, organic surfaces are neither sufficiently conductive or rigid enough to be examined directly with the STM. At present, nonconductive surfaces can be examined in two ways: 1) Using the AFM, which measures the deflection of a weak spring as it is dragged across the surface, or 2) coating or replicating non-conductive surfaces with metal layers so as to make them conductive, then imaging with the STM. However, we have found that the conventional freeze-fracture technique, while extremely useful for imaging bulk organic materials with STM, must be modified considerably for optimal use in the STM.

The atomic-force microscope and its future in biology

1993 ◽  
Vol 51 ◽  
pp. 704-705
Author(s):  
Jean-Paul Revel
Keyword(s):  
Silicon Nitride ◽  
Laser Beam ◽  
Atomic Force Microscope ◽  
Scanning Tunneling Microscope ◽  
Point Of View ◽  
Scanning Tunneling ◽  
Close Relative ◽  
Tunneling Microscope ◽  
Atomic Force ◽  
Sharp Point

The last few years have been marked by a series of remarkable developments in microscopy. Perhaps the most amazing of these is the growth of microscopies which use devices where the place of the lens has been taken by probes, which record information about the sample and display it in a spatial from the point of view of the context. From the point of view of the biologist one of the most promising of these microscopies without lenses is the scanned force microscope, aka atomic force microscope.This instrument was invented by Binnig, Quate and Gerber and is a close relative of the scanning tunneling microscope. Today's AFMs consist of a cantilever which bears a sharp point at its end. Often this is a silicon nitride pyramid, but there are many variations, the object of which is to make the tip sharper. A laser beam is directed at the back of the cantilever and is reflected into a split, or quadrant photodiode.

FIELD ION MICROSCOPE AND ATOM-PROBE STUDIES OF SCANNING TUNNELING MICROSCOPE TIPS

1988 ◽  
Vol 49 (C6) ◽  
pp. C6-55-C6-59 ◽  
Author(s):  
O. NISHIKAWA ◽  
K. HATTORI ◽  
F. KATSUKI ◽  
M. TOMITORI
Keyword(s):  
Scanning Tunneling Microscope ◽  
Atom Probe ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
Field Ion Microscope
Sign in / Sign up

Export Citation Format

Share Document