Selective‐area epitaxial growth of gallium arsenide on silicon substrates patterned using a scanning tunneling microscope operating in air

1990 ◽  
Vol 57 (23) ◽  
pp. 2437-2439 ◽  
Author(s):  
J. A. Dagata ◽  
W. Tseng ◽  
J. Bennett ◽  
C. J. Evans ◽  
J. Schneir ◽  
...  
Keyword(s):  
Gallium Arsenide ◽  
Epitaxial Growth ◽  
Scanning Tunneling Microscope ◽  
Scanning Tunneling ◽  
Silicon Substrates ◽  
Tunneling Microscope ◽  
Selective Area

Growth and Decay of Germanium Islands on Silicon Studied by High Temperature Stm

1999 ◽  
Vol 583 ◽  
Author(s):  
M. Kästner ◽  
B. Voigtländer
Keyword(s):  
High Temperature ◽  
Molecular Beam Epitaxy ◽  
Epitaxial Growth ◽  
Scanning Tunneling Microscope ◽  
Strain Energy ◽  
Molecular Beam ◽  
Three Dimensional ◽  
Scanning Tunneling ◽  
Two Dimensional ◽  
Tunneling Microscope

AbstractWe use a scanning tunneling microscope (STM) capable of imaging the growing layer at high temperature during molecular beam epitaxy (MBE) to study the epitaxial growth of Germanium on Silicon and the decay of Ge islands. The periodicity of the (2×N) reconstruction of two-dimensional Ge layers on Si(001) is measured as function of the Ge coverage. Strain energy drives the formation of the (2×N) reconstruction and Si/Ge intermixing. A comparison to total energy calculations predicting the periodicity of the (2×N) reconstruction is used to estimate the amount of Si-Ge intermixing near the surface. The evolution of the size and shape of individual “hut clusters” is measured and explained by kinetically self-limiting growth. The relaxation of kinetically a determined morphology towards equilibrium is followed for a Ge layer on Si(111). Strained two-dimensional as well as partially relaxed three-dimensional islands dissolve and are soaked up by larger three-dimensional islands which are dislocated and therefore fully relaxed.

MEASUREMENT OF CRITICAL EXPONENTS OF PLATINUM THIN FILMS

2003 ◽  
Vol 10 (01) ◽  
pp. 1-5 ◽  
Author(s):  
M. C. SALVADORI ◽  
L. L. MELO ◽  
M. CATTANI ◽  
O. R. MONTEIRO ◽  
I. G. BROWN
Keyword(s):  
Thin Films ◽  
Critical Exponents ◽  
Scanning Tunneling Microscope ◽  
Growth Dynamics ◽  
Scanning Tunneling ◽  
Silicon Substrates ◽  
Tunneling Microscope ◽  
Metal Plasma ◽  
Ion Deposition

We have fabricated platinum thin films by metal plasma ion deposition on silicon substrates. The roughness of these films has been measured by a scanning tunneling microscope (STM) and we have determined the growth dynamics critical exponents.

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.

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