From Point Defects to Amorphous Structures: Atomic Resolution Studies of Semiconductor Surfaces by Scanning Tunneling Microscopy (STM)

1990 ◽  
Vol 183 ◽  
Author(s):  
R. Wiesendanger ◽  
G. Tarrach ◽  
D. Buergler ◽  
L. Scandella ◽  
H.-J. Guentherodt
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Point Defects ◽  
Atomic Scale ◽  
Silicon Surfaces ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Linear Defects ◽  
Multiple Step ◽  
Step Edges

AbstractWe have studied point defects, linear defects as well as spatial transitions between ordered and disordered structures on silicon surfaces with atomic resolution by using scanning tunneling microscopy (STM). Point defects in the vicinity of multiple step edges as well as surface reconstructions at multiple step edges as high as 3 nm have been characterized by STM. STM images of partially disordered silicon surfaces prepared by laser and thermal annealing demonstrate the potential of STM for characterizing non-periodic surfaces on the atomic scale.

scholarly journals Atomic Resolution with the Atomic Force Microscope

1995 ◽  
Vol 3 (4) ◽  
pp. 6-7
Author(s):  
Stephen W. Carmichael
Keyword(s):  
Atomic Force Microscopy ◽  
Scanning Tunneling Microscopy ◽  
Atomic Force Microscope ◽  
Recent Article ◽  
Atomic Scale ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Atomic Force

For biologic studies, atomic force microscopy (AFM) has been prevailing over scanning tunneling microscopy (STM) because it has the capability of imaging non-conducting biologic specimens. However, STM generally gives better resolution than AFM, and we're talking about resolution on the atomic scale. In a recent article, Franz Giessibl (Atomic resolution of the silicon (111)- (7X7) surface by atomic force microscopy, Science 267:68-71, 1995) has demonstrated that atoms can be imaged by AFM.

Intrinsic Point Defects on a TiO2(110) Surface and Their Reaction with Oxygen: A Scanning Tunneling Microscopy Study

1997 ◽  
Vol 474 ◽  
Author(s):  
Markus Kuhn ◽  
J. F. Anderson ◽  
Jeremy Lehman ◽  
Talib Mahmoud ◽  
Ulrike Diebold
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Molecular Oxygen ◽  
Point Defects ◽  
Healing Process ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Defect Sites

ABSTRACTThe interaction of molecular oxygen, at room temperature, with a reduced TiO2(110) surface has been studied in situ by scanning tunneling microscopy (STM). Oxygen vacancies (point defects) were created on a clean TiO2(110) surface by annealing in ultra-high vacuum and successfully imaged on the atomic scale. These point defect sites were stable under ultrahigh vacuum conditions. During exposure to molecular oxygen, new point defects appear at different locations on the surface although their overall number is reduced. A mechanism for this dynamic healing process is proposed.

Probing nucleation and growth phenomena on silicon surfaces by scanning tunneling microscopy/spectroscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 406-407
Author(s):  
R.J. Hamers ◽  
U.K. Kohler ◽  
J.E. Demuth
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Chemical Reactivity ◽  
Nucleation And Growth ◽  
Silicon Surfaces ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Surface Geometry ◽  
Adsorption Sites ◽  
Localized Defects ◽  
Step Edges

Nucleation and growth processes at surfaces are determined by a complex interplay between surface diffusion and adsorption at terraces, step edges, and defects. Localized defects strongly affect both the electronic properties of the surfaces as well as their reactivity, therby affecting nucleation and growth. Reconstruction of seminconductor surfaces further complicates the picture, by providing various types of inequivalent adsorption sites even on “perfect” surfaces. In an effort to understand these processes at the atomistic level, we have used scanning tunneling microscopy to probe the epitaxial growth of silicon on Si(001) and Si(111)-(7×7) surfaces at temperatures where the diffusion length of the impinging adatoms is smaller than the spacing between steps, so that groth occurs through the formation of islands rather than at step edges. Scanning tunneling microscopy is capable of probing both the local surface geometry and local electronic structure, permitting adsorption and chemical reactivity to be studied on an atom-by-atom basis.

Scanning tunneling microscopy of polymers: A status report

1989 ◽  
Vol 47 ◽  
pp. 330-331
Author(s):  
P.E. Russell ◽  
I.H. Musselman
Keyword(s):  
High Resolution ◽  
Scanning Tunneling Microscopy ◽  
Sample Surface ◽  
Atomic Scale ◽  
Constant Current ◽  
Scanning Tunneling ◽  
Status Report ◽  
Tunneling Microscopy ◽  
Research Issues ◽  
Wide Range

Scanning tunneling microscopy (STM) has evolved rapidly in the past few years. Major developments have occurred in instrumentation, theory, and in a wide range of applications. In this paper, an overview of the application of STM and related techniques to polymers will be given, followed by a discussion of current research issues and prospects for future developments. The application of STM to polymers can be conveniently divided into the following subject areas: atomic scale imaging of uncoated polymer structures; topographic imaging and metrology of man-made polymer structures; and modification of polymer structures. Since many polymers are poor electrical conductors and hence unsuitable for use as a tunneling electrode, the related atomic force microscopy (AFM) technique which is capable of imaging both conductors and insulators has also been applied to polymers.The STM is well known for its high resolution capabilities in the x, y and z axes (Å in x andy and sub-Å in z). In addition to high resolution capabilities, the STM technique provides true three dimensional information in the constant current mode. In this mode, the STM tip is held at a fixed tunneling current (and a fixed bias voltage) and hence a fixed height above the sample surface while scanning across the sample surface.

Scanning Tunneling Microscopy of Amorphous Carbon Films

1990 ◽  
Vol 48 (1) ◽  
pp. 318-319
Author(s):  
Mircea Fotino ◽  
D.C. Parks
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Amorphous Carbon ◽  
Carbon Films ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Amorphous Carbon Films ◽  
Image Optimization ◽  
Step Procedure ◽  
Stm Images

In the last few years scanning tunneling microscopy (STM) has made it possible and easily accessible to visualize surfaces of conducting specimens at the atomic scale. Such performance allows the detailed characterization of surface morphology in an increasing spectrum of applications in a wide variety of fields. Because the basic imaging process in STM differs fundamentally from its equivalent in other well-established microscopies, good understanding of the imaging mechanism in STM enables one to grasp the correct information content in STM images. It thus appears appropriate to explore by STM the structure of amorphous carbon films because they are used in many applications, in particular in the investigation of delicate biological specimens that may be altered through the preparation procedures.All STM images in the present study were obtained with the commercial instrument Nanoscope II (Digital Instruments, Inc., Santa Barbara, California). Since the importance of the scanning tip for image optimization and artifact reduction cannot be sufficiently emphasized, as stressed by early analyses of STM image formation, great attention has been directed toward adopting the most satisfactory tip geometry. The tips used here consisted either of mechanically sheared Pt/Ir wire (90:10, 0.010" diameter) or of etched W wire (0.030" diameter). The latter were eventually preferred after a two-step procedure for etching in NaOH was found to produce routinely tips with one or more short whiskers that are essentially rigid, uniform and sharp (Fig. 1) . Under these circumstances, atomic-resolution images of cleaved highly-ordered pyro-lytic graphite (HOPG) were reproducibly and readily attained as a standard criterion for easily recognizable and satisfactory performance (Fig. 2).

Quantitative Scanning Tunneling Microscopy at Atomic Resolution: Influence of Forces and Tip Configuration

1996 ◽  
Vol 76 (8) ◽  
pp. 1276-1279 ◽  
Author(s):  
A. R. H. Clarke ◽  
J. B. Pethica ◽  
J. A. Nieminen ◽  
F. Besenbacher ◽  
E. Lægsgaard ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscopy

Atomic-scale surface science phenomena studied by scanning tunneling microscopy

2009 ◽  
Vol 603 (10-12) ◽  
pp. 1315-1327 ◽  
Author(s):  
F. Besenbacher ◽  
J.V. Lauritsen ◽  
T.R. Linderoth ◽  
E. Lægsgaard ◽  
R.T. Vang ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Surface Science ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Scale Surface
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