• Corrosion Science and Technology
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• v.9 no.6
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• pp.276-280
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• 2010

Copper(Cu) as an interconnecting metal layer can replace aluminum (Al) in IC fabrication since Cu has low electrical resistivity, showing high immunity to electromigration compared to Al. However, it is very difficult for copper to be patterned by the dry etching processes. The chemical mechanical polishing (CMP) process has been introduced and widely used as the mainstream patterning technique for Cu in the fabrication of deep submicron integrated circuits in light of its capability to reduce surface roughness. But this process leaves a large amount of residues on the wafer surface, which must be removed by the post-CMP cleaning processes. Copper corrosion is one of the critical issues for the copper metallization process. Thus, in order to understand the copper corrosion problems in post-CMP cleaning solutions and study the effects of DC biases and post-CMP cleaning solution concentrations on the Cu film, a constant voltage was supplied at various concentrations, and then the output currents were measured and recorded with time. Most of the cases, the current was steadily decreased (i.e. resistance was increased by the oxidation). In the lowest concentration case only, the current was steadily increased with the scarce fluctuations. The higher the constant supplied DC voltage values, the higher the initial output current and the saturated current values. However the time to be taken for it to be saturated was almost the same for all the DC supplied voltage values. It was indicated that the oxide formation was not dependent on the supplied voltage values and 1 V was more than enough to form the oxide. With applied voltages lower than 3 V combined with any concentration, the perforation through the oxide film rarely took place due to the insufficient driving force (voltage) and the copper oxidation ceased. However, with the voltage higher than 3 V, the copper ions were started to diffuse out through the oxide film and thus made pores to be formed on the oxide surface, causing the current to increase and a part of the exposed copper film inside the pores gets back to be oxidized and the rest of it was remained without any further oxidation, causing the current back to decrease a little bit. With increasing the applied DC bias value, the shorter time to be taken for copper ions to be diffused out through the copper oxide film. From the discussions above, it could be concluded that the oxide film was formed and grown by the copper ion diffusion first and then the reaction with any oxidant in the post-CMP cleaning solution.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.49-56
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• 2003

An experiment was conducted to study the effects of the dietary Cu sources on the performance of the weanling pigs. Forty-eight, 24 in each sex, 4 weeks old pigs were assigned to four treatments; control, methionine-Cu chelate, chitosan-Cu chelate or yeast-Cu chelate. Control diet contained 136ppm Cu to which additional 100ppm Cu in different chelated form was added to the respective treatment. Individual pig weight and feed intake of each pen were recorded weekly for 5 weeks. Average daily feed intakes(ADFI), average daily gains(ADG) and ADFI/ADG were not significantly different among treatments. Nutrient availability was not also significantly affected by treatments. Serum triglyceride concentration of chitosan-Cu treatment was significantly lower than those of methionine-Cu and yeast-Cu treatments but was not significantly different from that of the control. Serum cholesterol concentration of yeast-Cu was significantly lower than those of the control and methionine-Cu but was not significantly different from that of chitosan-Cu treatment. Serum HDL-cholesterol concentration was not significantly affected by treatments. Serum IgG concentrations of all copper treatments were significantly lower than that of the control. It was concluded that Cu-chelates supplemented to the basal diet (136ppm Cu) by the level of 100ppm Cu did not significantly affect growth performance of weaning pigs. However, serum parameters of cholesterol, cholesterol and IgG were significantly affected by the treatments.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_4
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• pp.189-196
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• 2001

The blue green alga, Microcystis aeruginosa, was found to accumulate proline under the stressful concentration of cupric ions. The changes of proline level in Microcystis aeruginosa in response to copper(Cu) have been monitored and the function of the accumulated proline was studied with respect to its effect on Cu uptake. Exposure of Microcystis aeruginosa elevated concentrations of Cu led to accumulation of fee proline depending on the concentrations of the metal in the external medium. The greater the toxicity or accumulation of the metal, the higher the amount of proline in algal cells were found. When proline was exogenously supplied prior to Cu treatment, the absorption of Cu was markedly reduced. When exogenous proline was supplied after Cu treatment, it resulted in a remarkable desorption of the adsorbed Cu immediately after the addition of proline. Pretreatment of Microcystis aeruginosa with proline counteracted with metal-induced lipid peroxidation. The results of the present study showed a protective elect of proline on metal toxicity through inhibition of lipid peroxidation and suggested that the accumulation of proline may be related to the tolerance mechanism for dealing with Cu stress.

• Journal of the Korean Ceramic Society
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• v.54 no.5
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• pp.438-442
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• 2017

This paper reports the facile synthesis of microlamella-structured porous copper (Cu)-oxide-based electrode and its potential application as an advanced anode material for lithium-ion batteries (LIBs). Nanowire-like Cu oxide, which is created by a simple thermal oxidation process, is radially and uniformly formed on the entire surface of Cu foam that has been fabricated using a combination of water-based slurry freezing and sintering (freeze casting). Compared to the Cu foil with a Cu oxide layer grown under the same processing conditions, the Cu foam anode with 63% porosity exhibits over twice as much capacity as the Cu foil (264.2 vs. 131.1 mAh/g at 0.2 C), confirming its potential for use as an anode electrode for LIBs.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.166-169
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• 2006

We fabricated hexagonal copper sulfide $Cu_2S$ nanowires to obtain a larger contact area of $Cu_2S/CdS$ solar cell. Copper sulfide nanowires were grown on Cu foil at room temperature by gas-sol id reaction. The size, density and shape of nanowires seemed to be affected by the change or reaction time temperature, crystallographic orientation of Cu foil, and molar ratio of the mixed gas. We controled the length and the diameter of the nanowires and we obtained suitable nanowire arrays which has fitting size for uniform deposition with n-type CdS. CdS layer was deposited on the nanowire array by electrodeposition and it seemed to be uniform. The $Cu_2S/CdS$ nanowires/CdS junction showed diode characteristics, A large contact area is expected with the $Cu_2S/CdS$ nanowire structure as compared with the $Cu_2S/CdS$ thin film.

• Korean Journal of Agricultural Science
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• v.51 no.1
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• pp.53-61
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• 2024

A total of 180 21-day-old weaning pigs ([Yorkshire × Landrace] × Duroc) with an initial body weight of 6.44 ± 0.01 kg were randomly assigned to 9 treatments for evaluating the effects of replacing dietary inorganic copper (Cu) and zinc (Zn) with glycine (Gly) or methionine (Met)-chelated Cu and Zn on growth performance and nutrient digestibility. The experimental period was 35 days. There were four replicated pens per treatment, with five pigs (three males and two females) per pen. Dietary treatments consisted of a basal diet (CON), in which the sources of Cu and Zn were in inorganic form. The inorganic Cu and Zn in the basal diet were replaced by glycine-chelated (GC) and methionine-chelated (MC) Cu and Zn by 30, 50, 70, or 100% to form the GC1, GC2, GC3, GC4, or MC1, MC2, MC3, MC4 groups. The 100% replacement of dietary inorganic Cu and Zn with GC or MC increased (p < 0.05) average daily gain, average daily feed intake, and gain-to-feed ratio. The complete replacement of dietary inorganic Cu and Zn with GC or MC led to enhanced (p < 0.05) digestibility of dry matter, nitrogen, Cu and Zn. Thus, the replacement of inorganic Cu and Zn with GC or MC can improve the growth efficiency and nutrient utilization of weaning pigs.

• Economic and Environmental Geology
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• v.46 no.6
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• pp.561-568
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• 2013

The copper mineralization in Peru is intimately associated with porphyry Cu deposits and subdivides into three porphyry Cu belt as Paleocene, Eocene-Oligocene, and Miocene. Up to now, the total copper production from them reach 28 Mt Cu. The total copper production from the Paleocene Cu belt, including Toquepala, Cuajone, and Cerro Verde, accounts for approximately 57% of total copper production from Peru. But focusing mineral exploration on middle southern (Eocene-Oligocene) and northwestern part (Miocene) of Peru results in new discoveries, including La Granja, El Galeno, Las Bambas, Toromocho, and Rio Blanco, which have an estimated annual production more than 200,000 t Cu. In addition to them, thirteen Cu deposits are discovered from the Paleocene, Eocene-Oligocene, and Miocene Cu belts. Thus, Peru is supposed to produce Cu production from 2014 and increases annual production from 143 Mt Cu in 2012 to 490 Mt Cu in 2019. Due to new discoveries, it is expected that mineral exploration activities in Peru are likely to move from Paleocene Cu belt to Eocene-Oligocene and Miocene Cu belts.

• Korean Journal of Materials Research
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• v.5 no.6
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• pp.657-666
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• 1995

Chemical vapor deposition of copper from the Cu(hfac)$_2$, Cu(II) hexafluoroacetylacetonate precursor, has been thermodynamically investigated by the minimization of Gibbs free energy of the system. For the Cu(hfac)$_2$-Ar system, carbon incorporation into the deposited films was observed in all the process conditions, which is presumably inherent from the thermal decomposition of the Cu(hfac)$_2$, precursor. For the Cu(hfac)$_2$-H$_2$system, lower temperatures were required than those of the Cu(hfac)$_2$-Ar system for the depositon of the copper films. Furthermore, we identified that the appearances of the condensed phases were sequentially changed from the codeposits of C(s)+CuF(s) to C(s)+CuF(s)+Cu(s), C(s)+Cu(s), Cu(s), and C(s), when the H$_2$input ratio and th reaction temperature were increased.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.33-42
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• 1999

Geometrically standardized dental radiographs were taken. We prepared Digital Cu-Equivalent Image Analyzing System for quantitative assessment of mandible bone. Images of radiographs were digitized by means of Quick scanner and personal Mcquintosh computer. NIH image as software was used for analyzing images. A stepwedge composed of 10 steps of 0.1mm copper foil in thickness was used for reference material. This study evaluated the effects of step numbers of copper wedge adopted for calculating equation. kVp and exposure time on the coefficient of determination(r²)of the equation for conversion to Cu-equivalent image and the coefficient of variation and Cu-Eq value(mm) measured at each copper step and alveolar bone of the mandible. The results were as follows: 1. The coefficients of determination(r²) of 10 conversion equations ranged from 0.9996 to 0.9973(mean=0.9988) under 70kVp and 0.16 sec. exposure. The equation showed the highest r was Y=4.75614612-0.06300524x +0.00032367x² -0.00000060x³. 2. The value of r² became lower when the equation was calculated from the copper stepwedge including 1.0mm step. In case of including 0mm step for calculation. the value of r showed variability. 3. The coefficient of variation showed 0.11, 0.20 respectively at each copper step of 0.2, 0.1mm in thickness. Those of the other steps to 0.9 mm ranged from 0.06 to 0.09 in mean value. 4. The mean Cu-Eq value of alveolar bone was 0.14±0.02mm under optimal exposure. The values were lower than the mean under the exposures over 0.20sec. in 60kVp and over 0.16sec. in 70kVp. 5. Under the exposure condition of 60kVp 0.16sec.. the coefficient of variation showed 0.03. 0.05 respectively at each copper-step of 0.3, 0.2mm in thickness. The value of r² showed over 0.9991 from both 9 and 10 steps of copper. The Cu-Eq value and the coefficient of variation was 0.14±0.01mm and 0.07 at alveolar bone respectively. In summary. A clinical application of this system seemed to be useful for assessment of quantitative assessment of alveolar provided high coefficient of determination is obtained by the modified adoption of copper step numbers and the low coefficient of variation for the range of Cu-Equivalent value of alveolar bone from optimal kVp and exposure time for each x-ray machine.

• Journal of Animal Science and Technology
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• v.50 no.3
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• pp.355-362
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• 2008

This study was carried out to evaluate effects of either organic or inorganic sources of both chromium and copper on growth performances, nutrients digestibility and fecal Cr, Cu, and Zn excretion in growing pigs. A total of 36 growing pigs((Landrace×Yorkshire)×Duroc, weighing 61.2kg in average) were allotted to 4 treatments with 3 replicates and 3 pigs per replicate. Four treatments were designated by supplemental sources of both chromium and copper as follows: ①200ppb Cr as Cr-methionine chelate(CrMet) and 200ppm Cuas copper methionine chelate(CuMet), ②200ppb Cr as CrMet and 200ppm Cu as copper sulfate(CuSO4), ③200ppb Cr as chromium chloride(CrCl3) and 200ppm Cu as CuMet, ④200ppb Cr as CrCl3 and 200ppm Cu as CuSO4. Growth performance was highest(p<0.05) in CrMet and CuMet supplemented diet treatment. Nutrients digestibility of diets was lowest(p<0.05) in CrMet and CuSO4 supplemented diet treatment, and highest(p<0.05) in CrMet and CuMet supplemented diet treatment. Fecal copper, zinc and chromium excretion was highest(p<0.05) in CrCl3 and CuSO4 supplementation treatment and lowest(p<0.05) in CrMet and CuMet supplementation treatment. This study showed a relatively high degree of utilization of Cr and Cu as well as Zn by supplementation of CrMet and CuMet compared with those of the inorganic sources.