scholarly journals Combined scanning force microscopy and scanning tunneling spectroscopy of an electronic nanocircuit at very low temperature

2007 ◽  
Vol 90 (4) ◽  
pp. 043114 ◽  
Author(s):  
J. Senzier ◽  
P. S. Luo ◽  
H. Courtois
Keyword(s):  
Low Temperature ◽  
Scanning Force Microscopy ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Force Microscopy ◽  
Scanning Force ◽  
Very Low Temperature

Scanned tip measurement of deep vertical facets on a flat surface: Measuring roughness on gaas laser waveguide mirrors

1993 ◽  
Vol 51 ◽  
pp. 532-533
Author(s):  
Chang Shen ◽  
Phil Fraundorf ◽  
Robert W. Harrick
Keyword(s):  
Integrated Circuits ◽  
Flat Surface ◽  
Scanning Force Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Optoelectronic Integrated Circuits ◽  
Laser Waveguide ◽  
Scanning Force ◽  
Gaas Laser

Monolithic integration of optoelectronic integrated circuits (OEIC) requires high quantity etched laser facets which prevent the developing of more-highly-integrated OEIC's. The causes of facet roughness are not well understood, and improvement of facet quality is hampered by the difficulty in measuring the surface roughness. There are several approaches to examining facet roughness qualitatively, such as scanning force microscopy (SFM), scanning tunneling microscopy (STM) and scanning electron microscopy (SEM). The challenge here is to allow more straightforward monitoring of deep vertical etched facets, without the need to cleave out test samples. In this presentation, we show air based STM and SFM images of vertical dry-etched laser facets, and discuss the image acquisition and roughness measurement processes. Our technique does not require precision cleaving. We use a traditional tip instead of the T shape tip used elsewhere to preventing “shower curtain” profiling of the sidewall. We tilt the sample about 30 to 50 degrees to avoid the curtain effect.

Log-log scale roughness spectroscopy of surfaces

1993 ◽  
Vol 51 ◽  
pp. 224-225
Author(s):  
P. Fraundorf ◽  
B. Armbruster
Keyword(s):  
Power Spectrum ◽  
Autocorrelation Function ◽  
Power Spectra ◽  
Scanning Force Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Scanning Force ◽  
Lateral Structure ◽  
Scale Roughness

Optical interferometry, confocal light microscopy, stereopair scanning electron microscopy, scanning tunneling microscopy, and scanning force microscopy, can produce topographic images of surfaces on size scales reaching from centimeters to Angstroms. Second moment (height variance) statistics of surface topography can be very helpful in quantifying “visually suggested” differences from one surface to the next. The two most common methods for displaying this information are the Fourier power spectrum and its direct space transform, the autocorrelation function or interferogram. Unfortunately, for a surface exhibiting lateral structure over several orders of magnitude in size, both the power spectrum and the autocorrelation function will find most of the information they contain pressed into the plot’s origin. This suggests that we plot power in units of LOG(frequency)≡-LOG(period), but rather than add this logarithmic constraint as another element of abstraction to the analysis of power spectra, we further recommend a shift in paradigm.

SPATIAL EVOLUTION OF THE BACKGROUND CONDUCTANCE IN THE TUNNELING SPECTRA IN Bi2Sr2-xLaxCuO6+δ

2007 ◽  
Vol 21 (18n19) ◽  
pp. 3190-3193
Author(s):  
T. KATO ◽  
T. MACHIDA ◽  
Y. KAMIJO ◽  
K. HARADA ◽  
R. SAITO ◽  
...  
Keyword(s):  
Low Temperature ◽  
Single Crystal ◽  
Spatial Variation ◽  
Energy Gap ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Spatial Evolution ◽  
Local Energy ◽  
Temperature Scanning

The spatial evolution of the background conductance in the tunneling spectra was investigated with low-temperature scanning tunneling spectroscopy on a slightly overdoped Bi 2 Sr 1.74 La 0.26 CuO 6+δ single crystal at 4.2 K. The asymmetry in the background conductance between positive and negative biases strongly correlates with the local energy gap, which shows the inhomogeneous spatial variation: the tunneling spectra become more asymmetric in the regions where the spectra exhibit larger gap value.

Measurement of Local Density of States by Scanning Tunneling Spectroscopy at Low Temperature

1987 ◽  
Vol 26 (S3-1) ◽  
pp. 627 ◽  
Author(s):  
Hiroshi Bando ◽  
Hiroshi Tokumoto ◽  
Wataru Mizutani ◽  
Kazuhiro Endo ◽  
Shigeru Wakiyama ◽  
...  
Keyword(s):  
Low Temperature ◽  
Density Of States ◽  
Local Density ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Local Density Of States
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