The Influence of Applied Current Density on Microstructural, Magnetic, and Morphological Properties of Electrodeposited Nanocrystalline Ni–Co Thin Films

2014 ◽  
Vol 28 (3) ◽  
pp. 1041-1045 ◽  
Author(s):  
Umut Sarac ◽  
M. Celalettin Baykul ◽  
Yasin Uguz
Keyword(s):  
Thin Films ◽  
Current Density ◽  
Morphological Properties ◽  
Applied Current ◽  
Applied Current Density

Stress-Induced and Electro-Migration of Electroplated Copper Thin Film Interconnections Used for 3D Integration

2011 ◽  
Author(s):  
Naoki Saito ◽  
Naokazu Murata ◽  
Kinji Tamakawa ◽  
Ken Suzuki ◽  
Hideo Miura
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Residual Stress ◽  
Grain Boundaries ◽  
Current Density ◽  
Annealed Film ◽  
Applied Current ◽  
Copper Thin Film ◽  
Applied Current Density ◽  
Electroplated Copper

Electroplated copper thin films have started to be applied to not only interconnections in printed wiring boards, but also thin film interconnections and TSV (Through Silicon Via) in semiconductor devices because of its low electric resistivity and high thermal conductivity. Thus, the electrical reliability of the electroplated copper interconnections was investigated experimentally. Self-made electroplated copper thin film interconnections were used for the evaluation. Electroplating conditions are as follows. The thin film interconnections were made by damascene process for electromigration tests. The applied current density during the test was varied from 1 MA/cm2 to 10 MA/cm2. Abrupt fracture caused by the local fusion was often observed in the as-electroplated interconnections within a few hours during the test. Since there were a lot of porous grain boundaries in the as-electroplated thin films, the local high Joule heating should have caused the fusion at one of the porous grain boundaries. Actually, it was confirmed that the failure rate increased linearly with the square of the amplitude of the applied current density. However, the diffusion of copper atoms caused by electromigration was enhanced significantly when the film was annealed at 400°C. Many voids and hillocks were observed on their surfaces. This change of the fracture mode clearly indicates the improvement of the crystallographic quality of the annealed film. It was also observed that the stress-induced migration was activated substantially in the annealed film. Large voids and hillocks grew during the custody of the film even at room temperature without any application of current. This stress-induced migration was caused by the increase of residual tensile stress of about 200 MPa in the annealed film. It was also found that sulfur atoms segregated in the grown hillocks, though no sulfur atoms were found by EDX in the initial as-electroplated interconnections or other area in the annealed thin film interconnections. Thus, the hillock formation in the annealed interconnections was enhanced by the segregation of sulfur atoms. These sulfur atoms should have been introduced into the electroplated films during electroplating. Therefore, it is very important to control the micro texture, the residual stress and the concentration of sulfur in the electroplated copper thin film interconnections to assure the stable life, in other words, to eliminate their sudden brittle fracture and time-dependent degradation caused by the residual stress in the thin film interconnections.

scholarly journals Methiocarb Degradation by Electro-Fenton: Ecotoxicological Evaluation

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5893
Author(s):  
Faléstine Souiad ◽  
Ana Sofia Rodrigues ◽  
Ana Lopes ◽  
Lurdes Ciríaco ◽  
Maria José Pacheco ◽  
...  
Keyword(s):  
Current Density ◽  
Iron Concentration ◽  
Model Organism ◽  
Anodic Current Density ◽  
Applied Current ◽  
Boron Doped Diamond ◽  
Applied Current Density ◽  
Toxic Units ◽  
Boron Doped ◽  
Ecotoxicological Evaluation

This paper studies the degradation of methiocarb, a highly hazardous pesticide found in waters and wastewaters, through an electro-Fenton process, using a boron-doped diamond anode and a carbon felt cathode; and evaluates its potential to reduce toxicity towards the model organism Daphnia magna. The influence of applied current density and type and concentration of added iron source, Fe2(SO4)3·5H2O or FeCl3·6H2O, is assessed in the degradation experiments of methiocarb aqueous solutions. The experimental results show that electro-Fenton can be successfully used to degrade methiocarb and to reduce its high toxicity towards D. magna. Total methiocarb removal is achieved at the applied electric charge of 90 C, and a 450× reduction in the acute toxicity towards D. magna, on average, from approximately 900 toxic units to 2 toxic units, is observed at the end of the experiments. No significant differences are found between the two iron sources studied. At the lowest applied anodic current density, 12.5 A m−2, an increase in iron concentration led to lower methiocarb removal rates, but the opposite is found at the highest applied current densities. The highest organic carbon removal is obtained at the lowest applied current density and added iron concentration.

Electrodeposition of Polyhedral Copper Crystals on Porous Silicon

2011 ◽  
Vol 181-182 ◽  
pp. 434-438
Author(s):  
Ming Meng ◽  
Yuan Ming Huang
Keyword(s):  
Porous Silicon ◽  
Current Density ◽  
Copper Chloride ◽  
Applied Current ◽  
Sem Images ◽  
Copper Crystal ◽  
Applied Current Density ◽  
Current Density Range ◽  
Tentative Explanation ◽  
Copper Crystals

Electrochemical deposition of copper from copper chloride aqueous electrolyte on porous silicon (PS) substrate was investigated in the current density range of 5 mA/cm2to 35 mA/cm2. Scanning electron microscopy (SEM) was utilized to characterize the surface morphology of as-electrodeposited PS. SEM images illustrate that the applied current density has a profound influence on the shape of copper crystal electrodeposited on the top surface of PS films. When the applied current density was fixed at 5mA/cm2, most of the copper crystals are in the shape of cube along with a small number of cuboid-shape. With the increasing current density, cuboid-shaped copper crystals gradually vanished. When the current density is up to the 35mA/cm2, we surprisingly observe that the cube shape predominates simultaneously with the emergence of truncated tetrahedron. A tentative explanation for the growth mechanism of copper crystal having various shapes is explored.

Investigation on the conductivity-dependent performance in low voltage cathodoluminescence

2015 ◽  
Vol 17 (15) ◽  
pp. 9936-9941 ◽  
Author(s):  
Chunyu Shang ◽  
Jinxian Zhao ◽  
Xiuqin Wang ◽  
Hongyang Xia ◽  
Hui Kang
Keyword(s):  
Current Density ◽  
Low Voltage ◽  
Generation Rate ◽  
Applied Current ◽  
Electron Hole ◽  
Phosphor Layer ◽  
Applied Current Density ◽  
Hole Generation

With the increase of applied current density in low voltage cathodoluminescence, the exciting power tends to saturate, causing the saturation of electron–hole generation rate in the phosphor layer.

Study of Forward Voltage Drift in Diffused SiC PiN Diodes Doped by Al or B

2005 ◽  
Vol 483-485 ◽  
pp. 989-992 ◽  
Author(s):  
S.I. Maximenko ◽  
Stanislav I. Soloviev ◽  
A.E. Grekov ◽  
A.V. Bolotnikov ◽  
Ying Gao ◽  
...  
Keyword(s):  
Current Density ◽  
Room Temperature ◽  
Stacking Faults ◽  
Applied Current ◽  
Forward Voltage ◽  
Pin Diodes ◽  
Applied Current Density ◽  
Voltage Drift ◽  
Significant Change ◽  
Degradation Testing

The degradation of diffused SiC PIN diodes during forward-biased operation was studied by first fabricating PIN diodes by diffusion of aluminum or boron into 4H-SiC substrates with n-type 10-15 µm thick epilayers doped by nitrogen up to 5x1015cm-3. The formed diodes were subjected to degradation testing under an applied current density of 200A/cm2 at room temperature. The majority of the Al diffused diodes demonstrated a voltage drift, ΔVf, of more than 2 V, while B-doped diodes showed no significant change in forward voltage. The EBIC mode of SEM was employed to monitor nucleation and expansion of stacking faults.

scholarly journals Dynamics of chiral solitons driven by polarized currents in monoaxial helimagnets

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Victor Laliena ◽  
Sebastian Bustingorry ◽  
Javier Campo
Keyword(s):  
Current Density ◽  
Steady Motion ◽  
Spin Transfer Torque ◽  
Spin Transfer ◽  
Applied Current ◽  
Applied Current Density ◽  
Magnetic Structures ◽  
And Control ◽  
Moriya Interaction ◽  
Chiral Solitons

AbstractChiral solitons are one dimensional localized magnetic structures that are metastable in some ferromagnetic systems with Dzyaloshinskii–Moriya interactions and/or uniaxial magnetic anisotropy. Though topological textures in general provide a very interesting playground for new spintronics phenomena, how to properly create and control single chiral solitons is still unclear. We show here that chiral solitons in monoaxial helimagnets, characterized by a uniaxial Dzyaloshinskii–Moriya interaction, can be stabilized with external magnetic fields. Once created, the soliton moves steadily in response to a polarized electric current, provided the induced spin-transfer torque has a dissipative (nonadiabatic) component. The structure of the soliton depends on the applied current density in such a way that steady motion exists only if the applied current density is lower than a critical value, beyond which the soliton is no longer stable.

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