Initial Stages of Oxide Formation on Copper Surfaces during Oxygen Bombardment at Room Temperature

2021 ◽  
Author(s):  
Robert Peter ◽  
Mladen Petravic
Keyword(s):  
Room Temperature ◽  
Oxide Formation ◽  
Copper Surfaces

STEM and ELS Observation of Early Oxide Formation on the Surface of Cr Thin Films

1980 ◽  
Vol 38 ◽  
pp. 412-413
Author(s):  
Fumio Watari ◽  
J. M. Cowley
Keyword(s):  
Thin Films ◽  
Optical System ◽  
Room Temperature ◽  
Oxide Formation ◽  
Initial Nucleation ◽  
Diffraction Patterns ◽  
Relationship Of ◽  
Multiple Twinning ◽  
Moderately High Temperature

STEM coupled with the optical system was used for the investigation of the early oxidation on the surface of Cr. Cr thin films (30 – 1000Å) were prepared by evaporation onto the polished or air-cleaved NaCl substrates at room temperature and 45°C in a vacuum of 10−6 Torr with an evaporation speed 0.3Å/sec. Rather thick specimens (200 – 1000Å) with various preferred orientations were used for the investigation of the oxidation at moderately high temperature (600 − 1100°C). Selected area diffraction patterns in these specimens are usually very much complicated by the existence of the different kinds of oxides and their multiple twinning. The determination of the epitaxial orientation relationship of the oxides formed on the Cr surface was made possible by intensive use of the optical system and microdiffraction techniques. Prior to the formation of the known rhombohedral Cr2O3, a thin spinel oxide, probably analogous to γ -Al203 or γ -Fe203, was formed. Fig. 1a shows the distinct epitaxial growth of the spinel (001) as well as the rhombohedral (125) on the well-oriented Cr(001) surface. In the case of the Cr specimen with the (001) preferred orientation (Fig. 1b), the rings explainable by spinel structure appeared as well as the well defined epitaxial spots of the spinel (001). The microdif fraction from 20A areas (Fig. 2a) clearly shows the same pattern as Fig. Ia with the weaker oxide spots among the more intense Cr spots, indicating that the thickness of the oxide is much less than that of Cr. The rhombohedral Cr2O3 was nucleated preferably at the Cr(011) sites provided by the polycrystalline nature of the present specimens with the relation Cr2O3 (001)//Cr(011), and by further oxidation it grew into full coverage of the rest of the Cr surface with the orientation determined by the initial nucleation.

Oxygen chemisorption and oxide formation on Ni silicide surfaces at room temperature

1984 ◽  
Vol 145 (2-3) ◽  
pp. 371-389 ◽  
Author(s):  
S Valeri ◽  
U Del Pennino ◽  
P Lomellini ◽  
P Sassaroli
Keyword(s):  
Room Temperature ◽  
Oxide Formation ◽  
Oxygen Chemisorption

Oxide formation on chromium metal surfaces by low-energy oxygen implantation at room temperature

2017 ◽  
Vol 636 ◽  
pp. 225-231 ◽  
Author(s):  
Robert Peter ◽  
Iva Saric ◽  
Ivna Kavre Piltaver ◽  
Ivana Jelovica Badovinac ◽  
Mladen Petravic
Keyword(s):  
Metal Surfaces ◽  
Room Temperature ◽  
Low Energy ◽  
Oxide Formation ◽  
Oxygen Implantation

Study of Ta as a Diffusion Barrier in Cu/SiO2 Structure

2000 ◽  
Vol 612 ◽  
Author(s):  
J. S. Pan ◽  
A. T. S. Wee ◽  
C. H. A. Huan ◽  
J. W. Chai ◽  
J. H. Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Room Temperature ◽  
Depth Profiling ◽  
Oxide Formation ◽  
X Ray ◽  
Chemical States ◽  
The Stability

AbstractTantalum (Ta) thin films of 35 nm thickness were investigated as diffusion barriers as well as adhesion-promoting layers between Cu and SiO2 using X-ray diffractometry (XRD), Scanning electron microscopy (SEM), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). After annealing at 600°C for 1h in vacuum, no evidence of interdiffusion was observed. However, XPS depth profiling indicates that elemental Si appears at the Ta/SiO2 interface after annealing. In-situ XPS studies show that the Ta/SiO2 interface was stable until 500°C, but about 32% of the interfacial SiO2 was reduced to elemental Si at 600°C. Upon cooling to room temperature, some elemental Si recombined to form SiO2 again, leaving only 6.5% elemental Si. Comparative studies on the interface chemical states of Cu/SiO2 and Ta/SiO2 indicate that the stability of the Cu/Ta/SiO2/Si system may be ascribed to the strong bonding of Ta and SiO2, due to the reduction of SiO2 through Ta oxide formation.

Oxygen chemisorption and oxide formation on Ni silicide surfaces at room temperature

1984 ◽  
Vol 145 (2-3) ◽  
pp. A376-A377
Author(s):  
S. Valeri ◽  
U. Del Pennino ◽  
P. Lomellini ◽  
P. Sassaroli
Keyword(s):  
Room Temperature ◽  
Oxide Formation ◽  
Oxygen Chemisorption

scholarly journals INCREASED NITRIC OXIDE SYNTHESIS IN PERITONEAL MACROPHAGES UNDER THE ACTION OF ASCORBIC ACID

2020 ◽  
Vol 17 (34) ◽  
pp. 273-281
Author(s):  
Zoia Veniaminovna KUROPTEVA ◽  
Larisa Michailovna BAYDER ◽  
Olga Leonidovna BELAYA ◽  
Taasilkan Toktomamatovna ZUMABAEVA
Keyword(s):  
Nitric Oxide ◽  
Ascorbic Acid ◽  
Cytotoxic Effect ◽  
Quantitative Assessment ◽  
Room Temperature ◽  
Uv Spectroscopy ◽  
Peritoneal Macrophages ◽  
Nitric Oxide Synthesis ◽  
Oxide Formation ◽  
Peritoneal Tissue

The effect of ascorbic acid (AA) on the formation of nitric oxide (NO) in peritoneal macrophages of SHK line mice was studied. ESR and UV spectroscopy revealed a significant increase in oxide formation in a suspension of macrophages with AA incubated at room temperature. In ESR studies, hemoglobin added to a suspension of macrophages was used as a NO trap, and the resulting nitric oxide was detected by the formation of hemoglobin complexes Heme-NO. The quantitative assessment showed that under these conditions, under the action of AA, 1.5x109 molecules of NO per cell are produced in macrophages. The increase in nitric oxide synthesis under the action of AA was also established by UV spectroscopy in the supernatant after incubation of MP with AA. Considering the known data on the cytotoxic effect of NO on viruses and bacteria, it is assumed that the effect of increasing nitric oxide synthesis in peritoneal, tissue MP and leukocytes under the action of AA is the main in the preventive and therapeutic effect of AA in a number of diseases, such as a sick of cold.

Pathway of zinc oxide formation by seed-assisted and controlled double-jet precipitation

CrystEngComm ◽  
2016 ◽  
Vol 18 (6) ◽  
pp. 924-929 ◽  
Author(s):  
Xu Yan ◽  
Liyuan Chai ◽  
Qingzhu Li ◽  
Lijun Ye ◽  
Bentao Yang ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Room Temperature ◽  
Oxide Formation ◽  
Short Time

ZnO can be well formed in a short time at room temperature via seed-assisted and controlled double-jet precipitation.

Adsorption of oxygen and carbon monoxide on DymCun bimetallic surfaces at room temperature

1987 ◽  
Vol 52 (10) ◽  
pp. 2392-2400
Author(s):  
Josef Kopešťanský
Keyword(s):  
Carbon Monoxide ◽  
Surface Layer ◽  
Room Temperature ◽  
Dipole Moments ◽  
Dissociative Adsorption ◽  
Copper Surfaces ◽  
Cu Content ◽  
Bimetallic Surfaces ◽  
Adsorbed Co ◽  
Alloy Segregation

The adsorption of oxygen and carbon monoxide on surfaces of dysprosium, copper, and their bimetallic “alloys” DymCun was studied by work function measurements. In the starting stage of adsorption of oxygen, copper surfaces are more reactive than dysprosium surfaces, and bulk oxide appears in the sub-surface copper layers at room temperature; this was also observed for the bimetallic surfaces, where the starting adsorption of oxygen took place nearly exclusively on copper. With dysprosium, the bulk oxide did not form at room temperature; instead, oxygen was adsorbed on the surface to form a layer consisting of species of two kinds with substantially different dipole moments. Carbon monoxide practically did not adsorb on copper at 25 °C, whereas on dysprosium it exhibited dissociative adsorption. On the bimetallic surfaces (DyCu and DyCu6) the amount of adsorbed CO decreased proportionally to the increasing Cu content of the alloy. Segregation of copper in the surface layer, observed for the bimetallic DymCun “alloys”, resulted in an additional decrease in the amount of adsorbed CO.

Organic Monolayers for Room Temperature Copper Bonding

2009 ◽  
Author(s):  
X. F. Ang ◽  
Q. H. Foo ◽  
J. Wei ◽  
Z. Chen ◽  
C. C. Wong
Keyword(s):  
Room Temperature ◽  
Surface Passivation ◽  
Bonding Temperature ◽  
Organic Layer ◽  
Wafer Level ◽  
Organic Monolayers ◽  
Effective Surface ◽  
Copper Surfaces ◽  
Organic Layers ◽  
Ultrathin Layer

Wafer level bonding process is a key fabrication step in several integration systems including microelectromechanical (MEMs) and nanoelectromechanical (NEMs). Often, harsh bonding conditions used result in large thermomechanical stresses built-up which leads to undesired degradation in device performance. Our recent study revealed the capability of nanostructured organic coatings (NSOCs) in reducing the bonding temperature needed to bond copper surfaces from 300°C to 60°C. In this study, room temperature copper bonding is demonstrated successfully with the help of the organic layers. Further investigation is made to evaluate the influence of thickness of NSOCs to alleviate bonding temperature. We found that all NSOCs (1, 2, 3) showed superior bond strength (>25MPa) as compared to that of the uncoated copper (<23MPa) at bonding temperatures from 25°C to 80°C. Since it is imperative that surface oxide has to be removed for bonding to take place, the enhancement exhibited is attributed to an effective surface passivation by the organic layer. It is postulated that this ultrathin layer, which behaves as a milder layer as compared to the bulk oxide layer, can be easily displaced for bond formation.

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