Current density profile extraction of focused ion beams based on atomic force microscopy contour profiling of nanodots

2002 ◽  
Vol 92 (7) ◽  
pp. 4037-4042 ◽  
Author(s):  
A. Lugstein ◽  
B. Basnar ◽  
G. Hobler ◽  
E. Bertagnolli
Keyword(s):  
Atomic Force Microscopy ◽  
Density Profile ◽  
Current Density ◽  
Ion Beams ◽  
Focused Ion Beams ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current Density Profile

Current Dependence of Reversible Electromigration Induced Resistance Changes in Short Al Lines and Interpretation of Irreversible Effects

1996 ◽  
Vol 428 ◽  
Author(s):  
A. H. Verbruggen ◽  
M. J. C. Van Den Homberg ◽  
A. J. Kalkman ◽  
J. R. Kraayeveld ◽  
A. W.-J. Willemsen ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Induced Resistance ◽  
Current Density ◽  
Linear Dependence ◽  
Resistance Change ◽  
Current Dependence ◽  
Force Microscopy ◽  
Atomic Force ◽  
Irreversible Effects ◽  
Current Densities

AbstractChanges in the electrical resistance induced by electromigration in short (< 20 μm) Al lines show a rather well-defined behavior. For current densities j below a critical value jc the resistance change saturates with time and the resistance fully recovers when the current is switched off. Above the critical current density the induced resistance changes do not saturate and vary approximately linearly with time. In this case the resistance changes recover only partially after removal of the current. We report (i) measurements of the current dependence of the magnitude of the reversible resistance changes and (ii) the results of atomic force microscopy (AFM) inspection of the lines after stressing with current densities above jc. The resistance measurements were made with a high-resolution AC bridge technique. The samples were pure, unpassivated Al lines with a film thickness of 100 nm and a line width of 2 gm. The results show a linear dependence between the magnitude of the reversible changes and the current density. The linear dependence is predicted by two models. The first is based on a description of the vacancy flux and the second on a description of the build-up of mechanical stress during an electromigration experiment. To study the origin of the irreversible effects, samples were stressed at current densities above jc, and the induced irreversible changes in the resistance were recorded. Both negative and positive changes of the resistance were observed. After six hours the experiment was stopped and the lines were inspected by atomic force microscopy. It was always possible to observe a void, a hillock or a hillock/void pair that was created during the passage of the DC current. Moreover, lines with decreasing resistance during stress always showed a hillock and lines with an increased resistance always showed a void.

scholarly journals Direct observation of damage clustering in irradiated DNA with atomic force microscopy

2019 ◽  
Vol 48 (3) ◽  
pp. e18-e18 ◽  
Author(s):  
Xu Xu ◽  
Toshiaki Nakano ◽  
Masataka Tsuda ◽  
Ryota Kanamoto ◽  
Ryoichi Hirayama ◽  
...  
Keyword(s):  
Dna Damage ◽  
Atomic Force Microscopy ◽  
Ionizing Radiation ◽  
Ion Beams ◽  
Dna Lesions ◽  
X Rays ◽  
Damage Site ◽  
Force Microscopy ◽  
Atomic Force ◽  
Clustered Dna Damage

Abstract Ionizing radiation produces clustered DNA damage that contains two or more lesions in 10–20 bp. It is believed that the complexity of clustered damage (i.e., the number of lesions per damage site) is related to the biological severity of ionizing radiation. However, only simple clustered damage containing two vicinal lesions has been demonstrated experimentally. Here we developed a novel method to analyze the complexity of clustered DNA damage. Plasmid DNA was irradiated with densely and sparsely ionizing Fe-ion beams and X-rays, respectively. Then, the resulting DNA lesions were labeled with biotin/streptavidin and observed with atomic force microscopy. Fe-ion beams produced complex clustered damage containing 2–4 lesions. Furthermore, they generated two or three clustered damage sites in a single plasmid molecule that resulted from the hit of a single track of Fe-ion beams. Conversely, X-rays produced relatively simple clustered damage. The present results provide the first experimental evidence for complex cluster damage.

QUANTITATIVE STUDY OF SURFACE MORPHOLOGY BY ATOMIC FORCE MICROSCOPY

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4395-4400
Author(s):  
Y. CHOI ◽  
N. I. CHO ◽  
J. I. CHOE
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Current Density ◽  
Chromic Acid ◽  
Average Surface Roughness ◽  
Peak Current Density ◽  
Average Surface ◽  
Force Microscopy ◽  
Atomic Force ◽  
Off Time

Atomic force microscopy was applied to study the formation and growth mechanism of thin multilayers of chromium-molybdenum and chrome prepared by electro-pulse plating, respectively. The chromium-molybdenum and chrome layers were prepared using direct current density of 1.6 mA.mm -2 and pulse currents with on-off time from 5 to 2000 ms in the bath containing 300g l-1 of chromic acid and 75g l-1 ammonium molybdate, and 250g l-1 of chromic acid and 5g l-1 of sulfuric acid, respectively. The higher current density enhanced nucleation rate which resulted in refining grain size. The micro-hardness of the pulse plated chrome and chromium-molybdenum alloy layers increased with the duration of on-off time and pulse current density. The average surface roughness of chrome layer is increased with increasing on/off time ratio for a given peak current density and voltage because the growth and dissolution mainly occurs during on-time and off-time, respectively. However, the average surface roughness of chromium-molybdenum alloy layer is decreased with increasing on/off time ratio for a given peak current density and voltage because the alloying element in the layer.

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