• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.34-39
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• 2011

Screen printing method is a common way to fabricate the crystalline silicon solar cell with low-cost and high-efficiency. The screen printing metallization use silver paste and aluminum paste for front and rear contact, respectively. Especially the rear contact between aluminum and silicon is important to form the back surface filed (Al-BSF) after firing process. BSF plays an important role to reduces the surface recombination due to $p^+$ doping of back surface. However, Al electrode on back surface leads to bow occurring by differences in coefficient of thermal expansion of the aluminum and silicon. In this paper, we studied the properties of mono crystalline silicon solar cell for rear electrode with aluminum and aluminum-boron in order to characterize bow and BSF of each paste. The 156*156 $m^2$ p-type silicon wafers with $200{\mu}m$ thickness and 0.5-3 ${\Omega}\;cm$ resistivity were used after texturing, diffusion, and antireflection coating. The characteristics of solar cells was obtained by measuring vernier callipers, scanning electron microscope and light current-voltage. Solar cells with aluminum paste on the back surface were achieved with $V_{OC}$ = 0.618V, JSC = 35.49$mA/cm^2$, FF(Fill factor) = 78%, Efficiency = 17.13%.

• Macromolecular Research
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• v.16 no.3
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• pp.204-211
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• 2008

A platinum-catalyzed polyelectrolyte porous membrane was prepared by solid-state compression of electrospun polystyrene (PS) fibers and in-situ metallization of counter-balanced ionic metal sources on the polymer surface. Using this ion-exchange metal-polymer composite system, fiber entangled pores were formed in the interstitial space of the fibers, which were surrounded by sulfonic acid sites ($SO_3^-$) to give a cation-selective polyelectrolyte porous bed with an ion exchange capacity ($I_{EC}$) of 3.0 meq/g and an ionic conductivity of 0.09 S/cm. The Pt loading was estimated to be 16.32 wt% from the $SO_3^-$ ions on the surface of the sulfonated PS fibers, which interact with the cationic platinum complex, $Pt(NH_3)_4^{2+}$, at a ratio of 3:1 based on steric hindrance and the arrangement of interacting ions. This is in good agreement with the Pt loading of 15.82 wt% measured by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The Pt-loaded sulfonated PS media showed an ionic conductivity of 0.32 S/cm. The in-situ metallized platinum provided a nano-sized and strongly-bound catalyst in robust porous media, which highlights its potential use in various electrochemical and catalytic systems.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.2
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• pp.33-41
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• 2022

Recent necessities of research have emerged about soft interconnection technologies for stable electric connections in flexible electronics. Mechanical failure in conventional metal solder interconnection can be solved as soft interconnections based on a small elastic modulus and a thin thickness. To enable stable electric connection while improving mechanical properties, highly conductive materials be thinned or mixed with a material that has a small elastic modulus. Representative soft interconnection technologies such as thin-film metallization, flexible conductive adhesives, and liquid metal interconnections are presented in this paper, and be focused on mechanical/electric properties improving strategies and their applications.

• Journal of the Korean institute of surface engineering
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• v.56 no.2
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• pp.160-168
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• 2023

Recently, investigation on metallization is a key for a stretchable display. Amorphous metal such as Ni and Zr based amorphous metal compounds are introduced for a suitable material with superelastic property under certain stress condition. However, Ni and Zr based amorphous metals have too high resistivity for a display device's interconnectors. In addition, these metals are not suitable for display process chemicals. Therefore, we choose an aluminum based amprhous metal Al-Mo as a interconnector of stretchable display. In this paper, Amorphous Forming Composition Range (AFCR) for Al-Mo alloys are calculated by Midema's model, which is between 0.1 and 0.25 molybdenum, as confirmed by X-ray diffraction (XRD). The elongation tests revealed that amorphous Al-20Mo alloy thin films exhibit superior stretchability compared to pure Al thin films, with significantly less increase in resistivity at a 10% strain. This excellent resistance to hillock formation in the Al20Mo alloy is attributed to the recessed diffusion of aluminum atoms in the amorphous phase, rather than in the crystalline phase, as well as stress distribution and relaxation in the aluminum alloy. Furthermore, according to the AES depth profile analysis, the amorphous Al-Mo alloys are completely compatible with existing etching processes. The alloys exhibit fast etch rates, with a reasonable oxide layer thickness of 10 nm, and there is no diffusion of oxides in the matrix. This compatibility with existing etching processes is an important advantage for the industrial production of stretchable displays.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.3
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• pp.1-10
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• 2023

Recently, as the demand for high-performance computers and mobile products increases, semiconductor packages are becoming high-integration and high-density. Therefore, in order to transmit a large amount of data at once, micro bumps such as flip-chip and Cu pillar that can reduce bump size and pitch and increase I/O density are used. However, when the size of the bumps is smaller than 70 ㎛, the brittleness increases and electrical properties decrease due to the rapid increase of the IMC volume fraction in the solder joint, which deteriorates the reliability of the solder joint. Therefore, in order to improve these issues, a layer that serves to prevent diffusion is inserted between the UBM (Under Bump Metallization) or pillar and the solder cap. In this review paper, various studies to improve bonding properties by suppressing excessive IMC growth of micro-bumps through additional layer insertion were compared and analyzed.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.4
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• pp.165-169
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• 2004

This paper reports a miniaturized conductor-backed CPW (CBCPW) bandpass filter based on a thin film polyimide layer coated on CMOS-grade silicon. With a 20 ${\mu}{\textrm}{m}$-thick polyimide interface layer and back metallization on the CMOS-grade silicon, the interaction of electromagnetic fields with the lossy silicon substrate has been isolated, and as a result a low-loss and low-dispersive CBCPW line has been obtained. Measured attenuation constant at 20 GHz is below 1.2 ㏈/cm, which is compatible with the CPW on GaAs. In addition, by using the proposed CBCPW geometry, miniaturized BPF for Ku band application is designed and its measured frequency response shows excellent agreement with the predicted value with validating the performances of the proposed CBCPW geometry for RFIC interconnects and filter applications.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1069-1071
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• 1995

The electrical properties of Al/TiN/Ti contact are investigated at submicron contacts. The contact resistance and contact leakage current are dependent on metallization, surface dopant concentration, semiconductor surface treatment and contact plug ion implantation. In this paper, the contact resistance and contact leakage current are studied according to surface dopant concentration, semiconductor surface treatment and contact plug ion implantation at 0.8 micron contact. The contact resistance and contact leakage current increases with increasing substrate ion concentration. HF cleaning represents high contact resistance but low contact leakage current while CDE cleaning represents low contact resistance but high contact leakage current. Contact plug ion implantation decreases contact resistance but increases contact leakage current. Specially, RTA represents good electrical properties.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.283-283
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• 2012

Sn/In은 금속 특징상 semimetal로 구분되어 지며 증착 두께가 적을수록 Island 구조를 가지며 높은 저항을 가져 비전도 특성을 가지는 금속으로 알려져 있다. 이런 특성이 산업적으로 IT기기의 Decoration에 적용되어 Sn/In을 증착하여 비전도(NCVM: Non Conductive Vacuum Metallization) 증착 Inmold Film으로 활용되고 있다. 비전도 특성은 IT기기의 안테나 성능에 영향을 주기 때문에 Sn/In 박막의 두께에 따른 전기적 특성을 관찰하였다. 또한 Sn/In의 증착 두께에 따라 Inmold Film의 증착감 및 색상 차이가 발생하는 것을 색차계를 통하여 확인할 수 있었다. Sn/In 증착은 Source를 이용하여 Electron beam 방법으로 PET/증착프라이머 Film 위에 Sn/In 박막을 증착 하였으며 증착 조건에 따라 Sn/In 박막특성에 미치는 영향을 연구하였다. 그리고 SEM측정을 통하여 증착조건에 따른 박막의 Morphology도 확인하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.342-342
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• 2012

Resistance-change Random Access Memory (ReRAM), which utilizes electrochemical control of nanoscale quantities of metal in thin films of solid electrolyte, shows great promise as a future solid state memory. The technology utilizes the electrochemical formation and removal of metallic pathways in thin films of solid electrolyte. Key attributes are low voltage and current operation, excellent scalability, and a simple fabrication sequence. In this study, we investigated the nature of thin films formed by photo doping of Ag+ ions into chalcogenide materials for use in solid electrolyte of programmable metallization cell devices. We measured the I-V characteristics by field-effect of the device. The results imply that a Ag-rich phase separates owing to the reaction of Ag with free atoms from chalcogenide materials.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.45.1-45.1
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• 2010

소성 온도에 따른 전면 전극과 태양전지 에미터와의 계면에서 전기적 특성을 평가하였다. Ag 전극 형성 시 특정 온도 이상의 열처리 과정을 통해 에미터와 전극 간 양질의 전기적 접촉을 형성하기 위해 소성 온도에 따라 Ag paste 내의 siver가 결정화되어 에미터 내부로 성장함을 확인 하고 Ag 전극의 전기적 특성을 평가하였다. 소성 온도 $650{\sim}750^{\circ}C$에서 전기적 특성이 가장 좋았으며 silver의 결정 생성에 의해 Ag paste와 에미터 간 전기적 접촉이 잘 형성됨을 확인 하였다.