• Journal of the Korean institute of surface engineering
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• v.29 no.5
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• pp.379-385
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• 1996

Adhesion of Cu/Cr and Cu/$Cu_xCr_{1-x}$ thin films onto polyimide substrates has been studied. For an adhesion layer, Cr or Cu-Cr alloy films were deposited onto polyimide using DC magnetron sputtering machine. Then Cu was sputter-deposited and finally, Cu was electroplated. Adhesion was evaluated using $90^{\circ}C$ peel test or T-peel test. Plastic deformation of the peeled metal layer was qualitatively measured using XRD technique. It is confirmed that high interfacial fracture energy and large plastic deformation are important to enhance the peel adhesion strength. High peel strength is obtained when the interface is strongly bonded. More ductile film has higher peel strength. In Cu-Cr alloy films, opposite effects of the Cr addition in the alloy film on the peel strength are operative: a beneficial effect of strong interfacial bonding and a negative effect of smaller plastic deformation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.366-367
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• 2005

The effect of benzotriazole (BTA) on the adhesion force of silica and pad particle on Cu/TEOS wafer surfaces was investigated with and without the addition of BTA. Cu-BTA had the isoelectric point (IEP) at around pH 4$\sim$8. Pad particles were more positive zeta potentials than silica. The adhesion force initially decreased of silica and pad particle on Cu surfaces when BTA was added. However, the more BTA was added, the more adhesion force gradually increased with the increase of BTA concentrations. Then the adhesion force of pad particle was higher than silica. And TEOS didn't resulted increasing adhesion force like Cu when BTA was added in DI water.

• Journal of the Korean Vacuum Society
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• v.6 no.S1
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• pp.122-126
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• 1997

the Cu/polyimide system is known to be the best candidate for a multilevel interconnection system due to the low resistance of Cu and to the low dielectric constant of polyimide respectively. Ion beam mixing of Cu(40nm)/polyimide was carried out at room temperature with 80 keV Ar+ and N2+ form $1.5\times$1015 to 15$\times$1015 ions/cm2. The quantitative adhesion strength was measured by a standard scratch test. X-ray photoelectron spectroscopy and x-ray emission spectrocopy are employed to investigate the chemical bonds and the interlayer compound formation of the films Cu/Al/polyimide showed more adhesion strength than Cu/polyimide after ion beam mixing and N2+ ions are more effective in the adhesion enhancement than Ar+ with the same sample geometry. The XES results shows the formation of interlayer compound of CuAl2O4 which can reflect more adhesive Cu/Al/polyimide which has not been reported previously. The latter results is understood by the fact that N2+ ions produce more pyridinelike moiety, amide group and tertiary amine moiety whcih are known as adhesion promotors.

• Journal of Adhesion and Interface
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• v.23 no.4
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• pp.108-115
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• 2022

In this study, we synthesized poly(itaconic acid-co-acrylamide) (IAcAAM) used as a novel polymer adhesion promoter to improve the adhesion strength of surface-treated Cu lead frames and epoxy composites. IAcAAM comprising itaconic acid, acrylamide was prepared through radical aqueous polymerization. The chemical structure and properties of IAcAAM was analyzed by FT-IR, ¹H-NMR, GPC, and DSC. The surface of the copper lead frame was treated with high temperature, alkali, and UV ozone to reduce the water contact angle and increase the surface energy. The adhesive strength of Cu lead frame and epoxy composite increased with the decrease of contact angle. The adhesive strength of Cu lead frame/epoxy composite increased with the addition of IAcAAM in epoxy composite. As silica content increased, the adhesive strength of Cu lead frame and epoxy composite tended to slightly decrease.

• Transactions on Electrical and Electronic Materials
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• v.1 no.3
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• pp.23-28
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• 2000

A block-oxide layer was formed on the surface of Cu-based leadframe by chamical oxidation method in order to enhance the adhesion strength between Cu-based leadframe and epoxy molding compound (EMC) Using sandwiched double cantilever beam (SDCB) specimens, the adesion strength was measured in terms of interfacial fracture toughness, G$\sub$IC//Results showed that the black-oxide layer was composed of two kinds of layers: pebble-like Cu$_2$O layer and acicular CuO layer, At the initial stage of oxidation the Cu$_2$O layer was preferentially formed and thickened up to around 200 nm whithin 1 minute of the oxidation time. Then the CuO layer started to from atop of the Cu$_2$O layer and thickened up to around 1300 nm until 20 minutes. As soon as the CuO layer formed, the thickness of Cu$_2$O layer began to reduce and finally reached to around 150 nm. The pre-cleaned and the Cu$_2$O coated leadframes showed almost no adhesion of EMC, however, as the CuO precipitates appeared and became continuous, G$\sub$IC/ increased up to around 80 J/㎡. Further oxidation raised G$\sub$IC/ up. to around 100 J/㎡.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.422-426
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• 2003

Cu thin films of $6000{\AA}$ thickness were deposited by Electron Beam Evaporation(EBE) method on the glass. The resistivity properties and adhesion of Cu thin films were investigated by various annealing and substrate temperature. Cu thin films were annealed in the air and vacuum condition for 10 min after the deposition. The resistivity and adhesion(the force required to separate films from substrates) was measured by 4-point probe and scratch testing. The resistivity of non-annealing Cu thin films was distinguished more substrate temperature loot than substrate temperature R.T, $200^{\circ}C$. In the case of air condition annealing, as heating temperature was increased, the resistivity was decreased. In the case of vacuum condition annealing, the resistivity was increased at heating temperature $200^{\circ}C$. The best resistivity($1.72\;{\mu}{\Omega}{\cdot}cm$) of Cu thin films was obtained by the air condition heating temperature $200^{\circ}C$ at the substrate heating temperature $100^{\circ}C$. As a result of scratch testing, adhesion was increased by annealing. And maximum adhesion had 600 gf.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.07a
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• pp.100-103
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• 2001

In this study, the adhesion and thermal property of the electroless-deposited Cu thin film were investigated. The multilayered structure of Cu/TaN/Si was fabricated by electroless-depositing the Cu thin layer on the TaN diffusion barrier which was deposited by MOCVD on the Si substrate. The thermal stability was investigated by measuring the resistivity as post-annealing temperature far the multilayered Cu/TaN/Si specimen which was annealed at Ar gas. The adhesion property of Cu 171ms was evaluated by the scratch test. The adhesion of the electroless-deposited Cu film was compared with other deposition methods of thermal evaporation and sputtering. The scratch test showed that the adhesion of electroless plated Cu film on TaN was better than those of sputtered Cu film and evaporated Cu film.

• Korean Journal of Materials Research
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• v.13 no.2
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• pp.133-136
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• 2003

Sn-2.5Cu alloy layers were deposited on the Alloy 42 lead-frame substrates by the electroplating method, and their microstructures, adhesion strength, and electrical resistivity were measured to evaluate the applicability of Sn-Cu alloy as a surface finishing material of electronic parts. The Sn-2.5Cu layers were electroplated in the granular form, and composed of pure Sn and Cu$_{6}$Sn$_{5}$ intermetallic compound. Surfaces of the electroplated Sn-2.5Cu layers were rather rough and also the thickness variance was large. The adhesion strength of the Sn-2.5Cu electroplated layers was highly comparable to that of the electroplated Cu alloy layer and the electrical conductivity was about 10 times higher than the pure Sn. After the 20$0^{\circ}C$ 30 min. annealing of the electroplated Sn-2.5Cu layers, the surface roughness was reduced, and adhesion strength and conductivity were improved. These results showed the Sn-Cu alloys can be used as an excellent surface finishing material.ial.

• Korean Journal of Materials Research
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• v.19 no.3
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• pp.119-124
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• 2009

In the microelectronics packaging industry, the adhesion strength between Cu and polyimide and the thermal stability are very important factors, as they influence the performance and reliability of the device. The three different buffer layers of Cr, 50%Cr-50%Ni, and Ni were adopted in a Cu/buffer layer/polyimide system and compared in terms of their adhesion strength and thermal stability at a temperature of $300^{\circ}C$ for 24hrs. A 90-degree peel test and XPS analysis revealed that both the peel strength and thermal stability decreased in the order of the Cr, 50%Cr-50%Ni and Ni buffer layer. The XPS analysis revealed that Cu can diffuse through the thin Ni buffer layer ($200{\AA}$), resulting in a decrease in the adhesion strength when the Cu/buffer layer/polyimide multilayer is heat-treated at a temperature of $300^{\circ}C$ for 24hrs. In contrast, Cu did not diffuse through the Cr buffer layer under the same heat-treatment conditions.

• Journal of the Korean institute of surface engineering
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• v.37 no.1
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• pp.5-12
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• 2004

The enhancement of adhesion for Cu film on polycarbonate (PC) surface with the $Ar/O_2$ gas plasma treatment and dc-bias sputtering was studied. The plasma treatment with this reactive mixture changes the chemical property of PC surface into hydrophllic one, which is shown by the variation of contact angle with surface modification. The micro surface roughness that also gives the high adhesive environment is increased by the $Ar/O_2$ gas plasma treatment. These results were observed distinctly from the atomic force microscopy (AFM). The negative substrate dc-bias effect for the Cu adhesion on PC was also investifated. Accelerated $Ar^{+}$ lons in sheath area of anode bombard the bare surface of PC during initial stage of dc bias sputtering. PC substrate. therefore, has severe roughen and hydrophilic surface due to the physical etching process with more activated functional group. As dc-bias sputtering process proceeds, morphology of Cu film shows better step coverage and dense layer. The results of peel test show the evidence of superiority of bias sputtering for the adhesion between metal Cu and PC.C.