scholarly journals Seedless Cu Electroplating on Co-W Thin Films in Low pH Electrolyte: Early Stages of Formation

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1914
Author(s):  
Rúben F. Santos ◽  
Bruno M. C. Oliveira ◽  
Alexandre Chícharo ◽  
Pedro Alpuim ◽  
Paulo J. Ferreira ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Barrier Layer ◽  
Photoelectron Spectroscopy ◽  
Ph Value ◽  
Film Structure ◽  
Current Application ◽  
Cu Films ◽  
Force Microscopy ◽  
Cu Electroplating ◽  
Microstructure Morphology

The use of Ta/TaN barrier bilayer systems in electronic applications has been ubiquitous over the last decade. Alternative materials such as Co-W or Ru-W alloys have gathered interest as possible replacements due to their conjugation of favourable electrical properties and barrier layer efficiency at reduced thicknesses while enabling seedless Cu electroplating. The microstructure, morphology, and electrical properties of Cu films directly electrodeposited onto Co-W or Ru-W are important to assess, concomitant with their ability to withstand the electroplating baths/conditions. This work investigates the effects of the current application method and pH value of the electroplating solution on the electrocrystallisation behaviour of Cu deposited onto a Co-W barrier layer. The film structure, morphology, and chemical composition were studied by X-ray diffraction, scanning electron microscopy and atomic force microscopy, as well as photoelectron spectroscopy. The results show that the electrolyte solution at pH 1.8 is incapable of creating a compact Cu film over the Co-W layer in either pulsed or direct-current modes. At higher pH, a continuous film is formed. A mechanism is proposed for the nucleation and growth of Cu on Co-W, where a balance between Cu nucleation, growth, and preferential Co dissolution dictates the substrate area coverage and compactness of the electrodeposited films.

Growth and Structure of Metallic Barrier Layer and Interconnect Films I: Exeriments

1999 ◽  
Vol 562 ◽  
Author(s):  
D. L. Windt ◽  
J. Dalla Tortre ◽  
G. H. Gilmer ◽  
J. Sapjeta ◽  
R. Kalyanaraman ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Barrier Layer ◽  
Orientation Angle ◽  
Film Surface ◽  
Growth Direction ◽  
Film Structure ◽  
Argon Pressure ◽  
Cu Films ◽  
Force Microscopy ◽  
Si Substrates

ABSTRACTWe present experimental results directed at understanding the growth and structure of metallic barrier layer and interconnect films. Numerical simulation results associated with this experimental work are presented in an accompanying paper in these proceedings. Here, thin films of Al, Ti, Cu and Ta have been grown by magnetron sputtering onto oxidized Si substrates. Using a specially-constructed substrate holder, the orientation of the substrate with respect to the growth direction was varied from horizontal to vertical. Films were grown at both low and high argon pressure; in the case of Ta, the cathode power was varied as well. The film structure and in particular the surface roughness was measured by X-ray reflectance and also by atomic force microscopy. We find that the surface roughness increases markedly with orientation angle in the case of Ta and Cu films, and in Ti films grown at high argon pressure. At low pressure, however, the Ti film surface roughness remains constant for all substrate orientations. No variation in roughness with either orientation angle or argon pressure was observed in the Al films. These results suggest that, under certain circumstances, shadowing effects and/or grain orientation (i.e., texture) competition during growth can give rise to lower density, more porous (and thus more rough) films, particularly at large orientation angles, as on sidewalls in sub-micron trenches.

Growth and Structure of Metallic Barrie Laye and Interconnect Films I: Exeriments

1999 ◽  
Vol 564 ◽  
Author(s):  
D. L. Windt ◽  
J. Dalla Torre ◽  
G. H. Gilmer ◽  
J. Sapjeta ◽  
R. Kalyanaraman ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Orientation Angle ◽  
Film Surface ◽  
Growth Direction ◽  
Film Structure ◽  
Argon Pressure ◽  
Cu Films ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force

AbstractWe present experimental results directed at understanding the growth and structure of metallic barrier layer and interconnect films. Numerical simulation results associated with this experimental work are presented in an accompanying paper in these proceedings. Here, thin films of Al, Ti, Cu and Ta have been grown by magnetron sputtering onto oxidized Si substrates. Using a specially-constructed substrate holder, the orientation of the substrate with respect to the growth direction was varied from horizontal to vertical. Films were grown at both low and high argon pressure; in the case of Ta, the cathode power was varied as well. The film structure and in particular the surface roughness was measured by X-ray reflectance and also by atomic force microscopy. We find that the surface roughness increases markedly with orientation angle in the case of Ta and Cu films, and in Ti films grown at high argon pressure. At low pressure, however, the Ti film surface roughness remains constant for all substrate orientations. No variation in roughness with either orientation angle or argon pressure was observed in the Al films. These results suggest that, under certain circumstances, shadowing effects and/or grain orientation (i.e., texture) competition during growth can give rise to lower density, more porous (and thus more rough) films, particularly at large orientation angles, as on sidewalls in sub-micron trenches.

scholarly journals Structural, spectroscopic and electrical properties of dc magnetron sputtered NiO thin films and an insight into different defect states

2021 ◽  
Vol 127 (5) ◽  
Author(s):  
Parashurama Salunkhe ◽  
Muhammed Ali A.V ◽  
Dhananjaya Kekuda
Keyword(s):  
Electrical Properties ◽  
Photoelectron Spectroscopy ◽  
Visible Region ◽  
Grazing Incidence ◽  
Defect States ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Fcc Phase ◽  
Nio Films

AbstractIn this article, we report a detailed study on the influence of sputter power on physical properties of the NiO films grown by DC magnetron sputtering. Structural studies carried out by Grazing Incidence X-ray diffraction (XRD) reveals the polycrystalline nature of the films with FCC phase. The crystallographic orientation (111) plane followed by (200), (220), and (311) plane were evident from the XRD spectra. The average crystallites sizes were estimated from the spectra, and the values were compared using three different plots such as Scherrer, Williamson–Hall and size–strain plot. The surface morphology was carried out by atomic force microscopy. The deposited samples show semitransparent behavior in the visible region and the estimated band gap increased from 2.70 to 3.34 eV with an increase in sputter power. Furthermore, X-ray photoelectron spectroscopy (XPS) core-level Ni2p spectra were deconvoluted and the observed $${\text{Ni}}2{\text{p}}_{{{\text{3/2}}}}$$ Ni 2 p 3/2 , $${\text{Ni}}2{\text{p}}_{{1/2}}$$ Ni 2 p 1 / 2 domain along with their satellite’s peaks were analyzed. Most importantly, XPS quantification data and Raman spectra confirm the presence of both $${\rm{Ni}}^{2+}$$ Ni 2 + and $${\rm{Ni}}^{3+}$$ Ni 3 + states in the NiO films. The electrical properties carried at room temperature revealed that the resistivity of the film significantly increased and a mobility of ~ 84 $${\rm{cm}}^{2}{\rm{V}}^{-1}{s}^{-1}$$ cm 2 V - 1 s - 1 was obtained.

Selectivity Studies On Tantalum Barrier Layer In Copper CMP

2003 ◽  
Vol 767 ◽  
Author(s):  
Arun Vijayakumar ◽  
Tianbao Du ◽  
Kalpathy B. Sundaram ◽  
Vimal Desai
Keyword(s):  
Barrier Layer ◽  
Photoelectron Spectroscopy ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Electrochemical Techniques ◽  
Copper Metallization ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Analysis Techniques ◽  
Diffusion Barrier Layer

AbstractCopper metallization in sub-0.18 μm semiconductor devices is achieved by combining the dual damascence techniques followed by chemical mechanical planarization (CMP). Tantalum and its nitride have been identified as the diffusion barrier layer for copper metallization. However, the wide differences in properties between copper and tantalum layers result in selectivity problems during CMP process. The aim of this work is to obtain a better understanding on the slurry selectivity for copper and tantalum and to develop slurries with best selectivity performance. In this work, the effect of several chemical parameters (abrasive type, oxidizer type, concentration, pH etc.) was studied through static and dynamic tests using advanced electrochemical techniques and surface analysis techniques. The surface layers of the statically etched copper and tantalum discs were investigated using X-ray photoelectron spectroscopy (XPS) and surface planarity was studied using atomic force microscopy (AFM). Polishing rates results show that alumina-based slurry polished copper very well whereas tantalum removal rate was low. However, for the silica-based slurry the tantalum shows much higher removal rate than copper and better surface planarity was obtained.

Characterization and Electrical Properties of WO3 Sensing Thin Films

1996 ◽  
Vol 459 ◽  
Author(s):  
C. Cantalini ◽  
S. Di Nardo ◽  
L. Lozzi ◽  
M. Passacantando ◽  
M. Pelino ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Photoelectron Spectroscopy ◽  
Electrical Response ◽  
Binding Energies ◽  
Gas Sensitivity ◽  
Force Microscopy ◽  
Dry Air ◽  
Atomic Force ◽  
Glancing Angle

ABSTRACTThe microstructure and the electrical properties of thermallyevaporated WO3 thin films have been investigated by glancing angle XRD, atomic force microscopy AFM, X-ray photoelectron spectroscopy XPS and dc techniques. Thin films of 1500 Å thickness have been obtained by evaporating high purity WO3 powders by an electricallyheated crucible at 5 × 10−4 Pa on sapphire substrates. Theas-deposited films have resulted to be amorphous. After annealing at 500°C in dry air for 6, 12 and 24 hours the films have shown well crystallized structures with preferential orientations of WO3 in the (200)direction. The increase of the annealing time has shown marked influence onthe microstructural features of the films surface, as highlighted by AFM investigations. The binding energies of W 4f7/2 have been close to that of WO3, the 24 h annealed yielded an O/W ratio close to 2.9 which is in good agreement with the theoretical one. The gas sensitivity, selectivity and stability of the annealed films in presence of NO2 gas (between 0.7 and 5 ppm) have been evaluated by measuring the electrical change of the film resistance in dry air and in gasatmosphere conditions. The influence of NO and Humidity interfering gases to the NO2 electrical response has been also evaluated. The 500 °C annealed at 24 h has shown better electrical properties in terms of NO2 sensitivity, stability and cross sensitivity effects.

Electroless Deposition of NiMoB Diffusion Barrier Layer Film for ULSI-Cu Metallization

2017 ◽  
Vol 727 ◽  
pp. 900-906
Author(s):  
Yue Chun Wang ◽  
Xiu Hua Chen ◽  
Wen Hui Ma ◽  
Xue Mei Liu ◽  
Yu Ping Li ◽  
...  
Keyword(s):  
Barrier Layer ◽  
Diffusion Barrier ◽  
Photoelectron Spectroscopy ◽  
Electroless Deposition ◽  
Copper Interconnects ◽  
X Ray ◽  
Force Microscopy ◽  
Cu Metallization ◽  
Atomic Force ◽  
Diffusion Barrier Layer

NiMoB alloy films were deposited on silicon substrate by electroless deposition for diffusion barrier application in copper interconnects technology. NiMoB(40nm)/SiO2/Si and NiMoB(20nm)/Cu (40nm)/NiMoB(40nm)/SiO2/Si samples were prepared and annealed at temperatures ranging from 400◦C to 600◦C. Samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Four Point Probes (FPP) and Atomic Force Microscopy (AFM) to investigate the phases, composition, sheet resistance and surface morphology. The results showed that electroless deposited NiMoB film can be used as an effective Cu diffusion barrier layer until 500◦C. And the failure mechanism is that NiMoB crystallized and grains grew after annealing at high temperature, a large number of Cu grains passed through NiMoB film via grain boundaries and then reacted with Si substrate and oxygen, causing the generation of highly resistive Cu4Si and CuO.

Ambient Dependence of Agglomeration Stability of Cu/Ta Films

1998 ◽  
Vol 514 ◽  
Author(s):  
J. W. Hartman ◽  
H. A. Atwater ◽  
Imran Hashim ◽  
Barry Chin ◽  
Fusen Chen
Keyword(s):  
Photoelectron Spectroscopy ◽  
Physical Vapor Deposition ◽  
Rutherford Backscattering Spectrometry ◽  
Time Resolved ◽  
Cu Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
Growth Characterization ◽  
Oxygen Contamination

ABSTRACTWe have investigated the effects of oxygen contamination on the agglomeration of thin Cu films fabricated by physical vapor deposition on Ta barriers. Thin Cu films on clean, ultrahigh vacuum-deposited Ta barriers were stable against agglomeration when annealed for several hours at temperatures as high as T=380°C. However, on Ta barriers intentionally contaminated with oxygen, agglomeration of Cu films occurred within minutes when annealed above 300°C. Time-resolved reflectivity was used to study film evolution and agglomeration in situ. Atomic force microscopy was used for post-growth characterization of agglomeration. Characterization of Ta barriers by X-ray photoelectron spectroscopy and Rutherford backscattering spectrometry demonstrated that clean Cu films on contaminated Ta barriers containing as little as 5% oxygen were unstable against agglomeration.

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

Linear electrical properties of striated muscle fibres observed with intracellular electrodes

1964 ◽  
Vol 160 (978) ◽  
pp. 69-123 ◽  
Keyword(s):  
Electrical Properties ◽  
Striated Muscle ◽  
Surface Membrane ◽  
Fibre Surface ◽  
Step Function ◽  
Muscle Fibres ◽  
Appreciable Effect ◽  
Current Application ◽  
Current Path ◽  
Wide Range

The linear electrical properties of muscle fibres have been examined using intracellular electrodes for a. c. measurements and analyzing observations on the basis of cable theory. The measurements have covered the frequency range 1 c/s to 10 kc/s. Comparison of the theory for the circular cylindrical fibre with that for the ideal, one-dimensional cable indicates that, under the conditions of the experiments, no serious error would be introduced in the analysis by the geometrical idealization. The impedance locus for frog sartorius and crayfish limb muscle fibres deviates over a wide range of frequencies from that expected for a simple model in which the current path between the inside and the outside of the fibre consists only of a resistance and a capacitance in parallel. A good fit of the experimental results on frog fibres is obtained if the inside-outside admittance is considered to contain, in addition to the parallel elements R m = 3100 Ωcm 2 and C m = 2.6 μF/cm 2 , another path composed of a resistance R e = 330 Ωcm 2 in series with a capacitance C e = 4.1 μF/cm 2 , all referred to unit area of fibre surface. The impedance behaviour of crayfish fibres can be described by a similar model, the corresponding values being R m = 680 Ωcm 2 , C m = 3.9 μF/cm 2 , R e = 35 Ωcm 2 , C e = 17 μF/cm 2 . The response of frog fibres to a step-function current (with the points of voltage recording and current application close together) has been analyzed in terms of the above two-time constant model, and it is shown that neglecting the series resistance would have an appreciable effect on the agreement between theory and experiment only at times less than the halftime of rise of the response. The elements R m and C m are presumed to represent properties of the surface membrane of the fibre. R e and C e are thought to arise not at the surface, but to be indicative of a separate current path from the myoplasm through an intracellular system of channels to the exterior. In the case of crayfish fibres, it is possible that R e (when referred to unit volume) would be a measure of the resistivity of the interior of the channels, and C e the capacitance across the walls of the channels. In the case of frog fibres, it is suggested that the elements R e , C e arise from the properties of adjacent membranes of the triads in the sarcoplasmic reticulum . The possibility is considered that the potential difference across the capacitance C e may control the initiation of contraction.

scholarly journals Photocatalytic reduction of graphene oxide with cuprous oxide film under UV-vis irradiation

2020 ◽  
Vol 59 (1) ◽  
pp. 207-214 ◽  
Author(s):  
Yao Wang ◽  
Jianqing Feng ◽  
Lihua Jin ◽  
Chengshan Li
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Photocatalytic Reduction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Reduced Graphene ◽  
Reduction Efficiency ◽  
Metal Organic ◽  
Reduction Effect

AbstractWe have grown Cu2O films by different routes including self-oxidation and metal-organic deposition (MOD). The reduction efficiency of Cu2O films on graphene oxide (GO) synthesized by modified Hummer’s method has been studied. Surface morphology and chemical state of as-prepared Cu2O film and GO sheets reduced at different conditions have also been investigated using atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Results show that self-oxidation Cu2O film is more effective on phtocatalytic reduction of GO than MOD-Cu2O film. Moreover, reduction effect of self-oxidation Cu2O film to GO is comparable to that of environmental-friendly reducing agent of vitamin C. The present results offer a potentially eco-friendly and low-cost approach for the manufacture of reduced graphene oxide (RGO) by photocatalytic reduction.

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