• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.86-86
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• 2003

Copper has attracted much attention in the deep submicron ULSI metallization process as a replacement for aluminum due to its lower resistivity and higher electromigration resistance. Electroless copper deposition method is appealing because it yields conformal, high quality copper at relatively low cost and a low processing temperature. In this work, it was investigated that effect of the microstructure of the substrate on the electroless deposition. The mechanism of the nucleation and growth of the palladium nuclei during palladium activation was proposed. Electroless copper deposition on TiN barriers using glyoxylic acid as a reducing agent was also investigated to replace toxic formaldehyde. Furthermore, electroless copper deposition on TaN$\sub$x/ barriers was examined at various nitrogen flow rate during TaN$\sub$x/ deposition. Finally, it was investigated that the effect of plasma treatment of as-deposited TaN$\sub$x/ harriers on the electroless copper deposition.

• Journal of the Korean institute of surface engineering
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• v.41 no.1
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• pp.23-27
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• 2008

The effect of solution agitation on the copper electroless deposition process of ULSI (ultra large scale integration) interconnections was investigated by using physical, electrochemical and electrical techniques. It was found that proper solution agitation was effective to obtain superconformal copper configuration within the trenches of $130{\sim}80nm$ width. The transition of open potential during electroless deposition process showed that solution agitation induced compact structure of copper deposits by suppressing mass transfer of cuprous ions toward substrate. Also, the specific resistivity of copper layers was lowered by increasing agitation speed, which made the deposited copper particles smaller. Considering both copper deposit configuration and electric property, around 500 rpm of solution agitation was the most suitable for the homogeneous electroless copper filling within the ultra-fine patterns.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.369-369
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• 2012

The present work deals with selective deposition of copper on fluoropolymers patterned silicon (111) surfaces. The pattern of fluoropolymer was fabricated by nanoimprint lithography (NIL) and plasma reactive ion etching (RIE) was used to remove the residuals layers. Copper was electrochemically deposited in bare Si regions which were not covered with fluoropolymers. The patterns of fluoropolymers and copper have been investigated by scanning electron microscopy (SEM). In this work, we used two deposition methods. One is galvanic displacement method and another is electrodeposition. Selective deposition works in both cases and it shows applicability to other materials. By optimization of the deposition conditions can be achieved therefore this process represents a simple approach for a direct high resolution patterning of silicon surfaces.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.178-178
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• 2010

With the scaling down of ULSI(Ultra Large Scale Integration) circuit of CMOS(Complementary Metal Oxide Semiconductor)based electronic devices, the electronic devices become more faster and smaller size that are promising field of semiconductor market. However, very narrow line width has some disadvantages. For example, because of narrow line width, deposition of conformal and thin barrier is difficult. Besides, proportion of barrier width is large, thus resistance is high. Conventional PVD(Physical Vapor Deposition) thin films are not able to gain a good quality and conformal layer. Hence, in order to get over these side effects, deposition of thin layer used of ALD(Atomic Layer Deposition) is important factor. Furthermore, it is essential that copper atomic diffusion into dielectric layer such as silicon oxide and hafnium oxide. If copper line is not surrounded by diffusion barrier, it cause the leakage current and devices degradation. There are some possible methods for improving the these secondary effects. In this study, TaNx, is used of Tertiarybutylimido tris (ethylamethlamino) tantalum (TBITEMAT), was deposited on the 24nm sized trench silicon oxide/silicon bi-layer substrate with good step coverage and high quality film using plasma enhanced atomic layer deposition (PEALD). And then copper was deposited on TaNx barrier using same deposition method. The thickness of TaNx was 4~5 nm. TaNx film was deposited the condition of under $300^{\circ}C$ and copper deposition temperature was under $120^{\circ}C$, and feeding time of TaNx and copper were 5 seconds and 5 seconds, relatively. Purge time of TaNx and copper films were 10 seconds and 6 seconds, relatively. XRD, TEM, AFM, I-V measurement(for testing leakage current and stability) were used to analyze this work. With this work, thin barrier layer(4~5nm) with deposited PEALD has good step coverage and good thermal stability. So the barrier properties of PEALD TaNx film are desirable for copper interconnection.

• Journal of the Korean institute of surface engineering
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• v.49 no.3
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• pp.238-244
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• 2016

Copper electrodeposition on AZ91 Mg alloy was studied in views of preferential deposition on ${\alpha}$- or ${\beta}$- phases and how to achieve uniform deposition over the entire surface on ${\alpha}$- and ${\beta}$-phases in a cyanide solution. The inhomogeneous microstructure of AZ91 Mg alloy, particularly ${\alpha}$- and ${\beta}$-phases, was found to result in non-uniform deposition of zincate layer, preferential deposition of zincate on ${\beta}$-phases, which leads to non-uniform growth of copper layer during the following electrodeposition process. The preferential depositions of zincate can be attributed to higher cathodic polarizations on the ${\beta}$-phases. Pin-hole defects in the copper electrodeposit were observed at the center of large size ${\beta}$-phase particles which is ascribed to gas bubbles formed at the ${\beta}$-phases. The activation of AZ91 Mg alloy in hydrofluoric acid solution was used to obtain uniform growth of zincate layer on both the ${\alpha}$- and ${\beta}$-phases. By choosing an optimum activation time, a uniform zincate layer was obtained on the AZ91 Mg alloy surface and thereby uniform growth of copper was obtained in a cyanide copper electroplating solution.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.180-182
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• 2002

Copper thin films are prepared by a chemical vapor deposition technology for multi-level metallzations in ULSI fabrication. The copper films were deposited on TiN/Si substrates in helium atmosphere with the substrate temperature between $120^{\circ}C$ and $300^{\circ}C$. In order to get more reliable metallizations, effects on the post-annealing treatment to the electrical properties of the copper films have been investigated. The Cu films were annealed at the $5\times$10^{-6}$ Torr vacuum condition, and the electrical resistivity and the nano-structures were measured for the Cu films. The electrical resistivity of Cu films shown to be reduced by the post-annealing. The electrical resistivity of 2.2 $\mu$$\Omega$.cm was obtained for the sample deposited at the substrate temperature of $180^{\circ}C$ after vacuum annealed at $300^{\circ}C$. The resistivity variations of the films was not exactly matched with the size of the nato-structures of the copper grains, but more depended on the deposition temperature of the copper films.

• Transactions on Electrical and Electronic Materials
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• v.13 no.2
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• pp.78-84
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• 2012

An in-situ optical monitoring method for real-time process monitoring of electrochemical copper deposition (CED) is presented. Process variables to be controlled in achieving desired process results are numerous in the CED process, and the importance of the chemical bath conditions cannot be overemphasized for a successful process. Conventional monitoring of the chemical solution for CED relies on the pH value of the solution, electrical voltage level for the reduction of metal cations, and gravity measurement by immersing sensors into a plating bath. We propose a nonintrusive optical monitoring technique using three types of optical sensors such as chromatic sensors and UV/VIS spectroscopy sensors as potential candidates as a feasible optical monitoring method. By monitoring the color of the plating solution in the bath, we revealed that optically acquired information is strongly related to the thickness of the deposited copper on the wafers, and that the chromatic information is inversely proportional to the ratio of $Cu$ (111) and {$Cu$ (111)+$Cu$ (200)}, which can used to measure the quality of the chemical solution for electrochemical copper deposition in advanced interconnection technology.

• Korean Journal of Materials Research
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• v.9 no.6
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• pp.583-588
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• 1999

The characteristics of copper thin films and pattern filling capability were investigated by ECD. Prior to deposition of copper film, seed-Cu/Ta(TaN)/$SIO_2$(BPSG)/Si structure was manufactured. Copper deposition was performed with various current waveforms(DC/PC, 1~10,000Hz) and current densities(10~60 mA/$\textrm{cm}^2$) after pretreatment (Oxident removal, wetting) of seed-layer. Conformal pattern filling was performed using PC method with fast deposition rate of 6,000~8,000$\AA$/min. Heat-treated($450^{\circ}C$, 30min) copper films showed good resistivities of 1.8~2.1$\mu$$\Omega$.cm. According to the XRD analysis, (111)-preferred orientation of copper film was found in ECD-Cu/seed-Cu/Ta/$Sio_2$/Si structure. Also, we have successfully achieved to fill via holes with 0.35$\mu\textrm{m}$ width and 4:1 aspect ratio.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.13-14
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• 2008

A high rate magnetron sputtering source (HRMSS) was employed to deposit thick copper films. The HRMSS was manufactured by changing the magnet size, arrangement, and field intensity. For the preparation of thick copper films, the copper sputtering conditions using HRMSS were characterized based on the deposition parameters such as discharge characteristics, I-V characteristics of the source, and change of deposition rate. The deposition rate of copper turned out to be more than 5 times than that of conventional magnetron sputtering source. Thick copper films having thickness of more than $20{\mu}m$ were prepared by using HRMSS. The morphology and orientation of the films were investigated by scanning electron microscopy and x-ray diffraction.

• Economic and Environmental Geology
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• v.17 no.4
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• pp.245-258
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• 1984

Geoje copper ore deposits are fissure filled copper veins which developed in late Cretaceous pyroclastics, andesite and shale. Mineral paragenesis reveals a division of the hydrothermal mineralization into three stages: Stage I, deposition of pyrite, magnetite, specularite, quartz and chlorite; Stage II, deposition of chalcopyrite, sphalerite, galena, tetrahedrite, aikinite, cosalite, electrum, quartz and chlorite; Stage III, deposition of barren calcite. Filling temperatures of fluid inclusions in quartz of stage I range from 171 to $282^{\circ}C$ whereas fluid inclusions in quartz and sphalerite of stage II range from 213 to $262^{\circ}C$ and from 186 to $301^{\circ}C$ respectively. Salinities of fluid inclusions in quartz of stage I range from 5.2 to 11.2 weight percent equivalent to NaCl. Salinities of fluid inclusions in quartz and sphalerite of stage II range from 6.6 to 10.9 and from 7.1 to 14.4 weight percent equivalent NaCl. Salinities of ore fluid during major mineralization stage in this deposits reveal nearly the same ranges as those of many copper deposits in Koseong copper mining district which located about 30km apart from Geoje mine. But filling temperatures of fluid inclusions formed during major copper mineralization stage in this deposits show slightly lower than those of copper deposits in Koseong copper mining district.