An in Situ Stm Study of Cu and Ni Electrodeposition

1995 ◽  
Vol 404 ◽  
Author(s):  
T. P. Moffat
Keyword(s):  
Phosphoric Acid ◽  
Mass Transport ◽  
Nickel Deposition ◽  
Reaction Proceeding ◽  
Step Flow ◽  
Metal Lattice ◽  
Surface Steps ◽  
Transport Control ◽  
Cuprous Ion

AbstractAn STM study has been initiated to investigate the various processes associated with electrodeposition of Cu-Ni multilayers on Cu (100). The substrates were prepared by electropolishing in phosphoric acid followed by immersion in 10 mmol/l HCl. A (√2×√) R°45 adlattice of oxidatively adsorbed chlorine is formed under these conditions. The adlayer stabilizes the surface steps in the 〈100〉 direction which corresponds to the close packed direction of the chloride adlattice. In dilute mmo1/1 solutions of cuprous ion, reduction occurs under mass transport control with the electrocrystallization reaction proceeding by step flow in the 〈100〉 direction. At more negative potentials chloride is reductively desorbed. Coincident with desorption the highly kinked metal steps become frizzy and move towards adopting the close packed 〈110〉 orientation of the metal lattice. Preliminary experiments on heteroepitaxial nickel deposition reveal regions where electrocrystallization on Cu(100) occurs via step flow in the 〈110〉 direction.

Role of boundaries in the crystallization of amorphous films

1988 ◽  
Vol 46 ◽  
pp. 626-627
Author(s):  
D. A. Smith
Keyword(s):  
Low Temperature ◽  
Amorphous State ◽  
Nucleation And Growth ◽  
Amorphous Films ◽  
Island Nucleation ◽  
Surface Steps ◽  
Transmission Electron ◽  
Component Systems ◽  
Temperature Deposition

The nucleation and growth processes which lead to the formation of a thin film are particularly amenable to investigation by transmission electron microscopy either in situ or subsequent to deposition. In situ studies have enabled the observation of island nucleation and growth, together with addition of atoms to surface steps. This paper is concerned with post-deposition crystallization of amorphous alloys. It will be argued that the processes occurring during low temperature deposition of one component systems are related but the evidence is mainly indirect. Amorphous films result when the deposition conditions such as low temperature or the presence of impurities (intentional or unintentional) preclude the atomic mobility necessary for crystallization. Representative examples of this behavior are CVD silicon grown below about 670°C, metalloids, such as antimony deposited at room temperature, binary alloys or compounds such as Cu-Ag or Cr O2, respectively. Elemental metals are not stable in the amorphous state.

Electrodeposition of Strained-Layer Superlattices

1996 ◽  
Vol 451 ◽  
Author(s):  
T. P. Moffat
Keyword(s):  
Charge Transfer ◽  
Mass Transport ◽  
Structural Evolution ◽  
Iron Group ◽  
Morphological Instability ◽  
Group Metal ◽  
Iron Group Metal ◽  
Transport Control ◽  
Strained Layer Superlattices ◽  
Interfacial Charge

ABSTRACTA variety of Cu/(Ni, Co) multilayers have been grown on Cu single crystals by pulse plating from an alloy electroplating bath. Copper is deposited under mass transport control while the iron group metal is deposited under interfacial charge transfer control. The structural evolution of these films is influenced by the morphological instability of the mass transport limited copper deposition reaction and the development of growth twins during iron-group metal deposition. Specular films have been obtained for growth on Cu(100) while rough, defective films were typically obtained for growth on Cu(111) and Cu(110).

Oblique-incidence Reflectivity Difference (OI-RD) and Leed Studies of Adsorption and Growth of Xe on Nb(110)

2003 ◽  
Vol 780 ◽  
Author(s):  
P. Thomas ◽  
E. Nabighian ◽  
M.C. Bartelt ◽  
C.Y. Fong ◽  
X.D. Zhu
Keyword(s):  
Transition Layer ◽  
Layer Growth ◽  
Flow Mode ◽  
Layer By Layer ◽  
Zeroth Order ◽  
Step Flow ◽  
Low Energy Electron Diffraction ◽  
Oriented Film ◽  
Low Energy Electron

AbstractWe studied adsorption, growth and desorption of Xe on Nb(110) using an in-situ obliqueincidence reflectivity difference (OI-RD) technique and low energy electron diffraction (LEED) from 32 K to 100 K. The results show that Xe grows a (111)-oriented film after a transition layer is formed on Nb(110). The transition layer consists of three layers. The first two layers are disordered with Xe-Xe separation significantly larger than the bulk value. The third monolayer forms a close packed (111) structure on top of the tensile-strained double layer and serves as a template for subsequent homoepitaxy. The adsorption of the first and the second layers are zeroth order with sticking coefficient close to one. Growth of the Xe(111) film on the transition layer proceeds in a step flow mode from 54K to 40K. At 40K, an incomplete layer-by-layer growth is observed while below 35K the growth proceeds in a multilayer mode.

scholarly journals Electrokinetic and in situ spectroscopic investigations of CO electrochemical reduction on copper

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jing Li ◽  
Xiaoxia Chang ◽  
Haochen Zhang ◽  
Arnav S. Malkani ◽  
Mu-jeng Cheng ◽  
...  
Keyword(s):  
Mass Transport ◽  
Active Sites ◽  
Gas Diffusion ◽  
Reduction Reaction ◽  
Adsorbed Hydrogen ◽  
Diffusion Type ◽  
Proton Coupled Electron Transfer ◽  
Alkaline Electrolytes ◽  
Reaction Orders

AbstractRigorous electrokinetic results are key to understanding the reaction mechanisms in the electrochemical CO reduction reaction (CORR), however, most reported results are compromised by the CO mass transport limitation. In this work, we determined mass transport-free CORR kinetics by employing a gas-diffusion type electrode and identified dependence of catalyst surface speciation on the electrolyte pH using in-situ surface enhanced vibrational spectroscopies. Based on the measured Tafel slopes and reaction orders, we demonstrate that the formation rates of C2+ products are most likely limited by the dimerization of CO adsorbate. CH4 production is limited by the CO hydrogenation step via a proton coupled electron transfer and a chemical hydrogenation step of CO by adsorbed hydrogen atom in weakly (7 < pH < 11) and strongly (pH > 11) alkaline electrolytes, respectively. Further, CH4 and C2+ products are likely formed on distinct types of active sites.

In Situ Determination of Acidity Level in Concentrated Phosphoric Acid Solutions by Potentiometric Method at Imposed Current Intensity

1997 ◽  
Vol 101 (1) ◽  
pp. 65-69 ◽  
Author(s):  
B. Hammouti ◽  
H. Oudda ◽  
A. Elmaslout ◽  
A. Benayada ◽  
J. Bessiere
Keyword(s):  
Phosphoric Acid ◽  
Potentiometric Method ◽  
Current Intensity ◽  
Acid Solutions ◽  
Acidity Level

High Quality Epitaxial Growth on in-Situ Patterned Inp Substrates

1989 ◽  
Vol 145 ◽  
Author(s):  
H. Temkin ◽  
L. R. Harriott ◽  
J. Weiner ◽  
R. A. Hamm ◽  
M. B. Panish
Keyword(s):  
Epitaxial Growth ◽  
Ion Beam ◽  
Low Energy ◽  
High Quality ◽  
Lithography Process ◽  
Luminescence Efficiency ◽  
Surface Steps ◽  
Inp Substrates ◽  
Vacuum Lithography

AbstractWe demonstrate a vacuum lithography process which uses a finely focused Ga ion beam to write the pattern which is then transferred to the InP pattern by low energy dry etching. Surface steps on the order of 1000-2000A in height, and lateral resolution limited only by size of the ion beam, can be efficiently prepared using moderate Ga ion fluences. The surfaces prepared by this process are damage free and suitable for epitaxial overgrowth. GaInAs/InP heterostructures grown on in-situ patterned substrates show excellent morphology and high luminescence efficiency.

Effect of mass transport along interfaces and grain boundaries on copper interconnect degradation

2004 ◽  
Vol 812 ◽  
Author(s):  
Ehrenfried Zschech ◽  
Moritz A. Meyer ◽  
Eckhard Langer
Keyword(s):  
Mass Transport ◽  
Grain Boundaries ◽  
Void Formation ◽  
Degradation Process ◽  
Copper Interconnects ◽  
Second Phase ◽  
Copper Interconnect ◽  
Void Evolution ◽  
Two Phases

AbstractIn-situ SEM electromigration studies were performed at fully embedded via/line interconnect structures to visualize the time-dependent void evolution in inlaid copper interconnects. Void formation, growth and movement, and consequently interconnect degradation, depend on both interface bonding and copper microstructure. Two phases are distinguished for the electromigration-induced interconnect degradation process: In the first phase, agglomerations of vacancies and voids are formed at interfaces and grain boundaries, and voids move along weak interfaces. In the second phase of the degradation process, they merge into a larger void which subsequently grows into the via and eventually causes the interconnect failure. Void movement along the copper line and void growth in the via are discontinuous processes, whereas their step-like behavior is caused by the copper microstructure. Directed mass transport along inner surfaces depends strongly on the crystallographic orientation of the copper grains. Electromigration lifetime can be drastically increased by changing the copper/capping layer interface. Both an additional CoWP coating and a local copper alloying with aluminum increase the bonding strength of the top interface of the copper interconnect line, and consequently, electromigration-induced mass transport and degradation processes are reduced significantly.

Enhancing Performance of Organic Electrosynthesis through Electrolyte Engineering and Mass Transport Control

2021 ◽  
Vol MA2021-01 (43) ◽  
pp. 1752-1752
Author(s):  
Miguel A Modestino ◽  
Daniela Eugenia Blanco
Keyword(s):  
Mass Transport ◽  
Transport Control
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