• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.16-17
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• 2006

In this paper, Ni-V alloy was studied with different structures and thickness. In case of Ni-V and Ni-V/Co/TiN, low resistive Ni silicide was formed after one step RTP (Rapid Thermal Process) with temperature range from $400^{\circ}C$ to $600^{\circ}C$ for 30sec in vacuum. After furnace annealing with temperatures range from $550^{\circ}C$ to $650^{\circ}C$ for 30min in nitrogen ambient, Ni-V single structure shows the best thermal stability compare with the other ones. To enhance the thermal stability up to 650oC and find the optimal thickness of Ni silicide, different thickness of Ni-V was studied in this work. Stable sheet resistance was obtained through Ni-V single structure with optimal Ni-V thickness.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.192-193
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• 2007

An evaporated Ti/Pd/Ag contact system is most widely used to make high-efficiency silicon solar cells, however, the system is not cost effective due to expensive materials and vacuum techniques. Commercial solar cells with screen-printed contacts formed by using Ag paste suffer from a low fill factor and a high shading loss because of high contact resistance and low aspect ratio. Low-cost Ni and Cu metal contacts have been formed by using electro less plating and electroplating techniques to replace the Ti/Pd/Ag and screen-printed Ag contacts. Ni/Cu alloy is plated on a silicon substrate by electro-deposition of the alloy from an acetate electrolyte solution, and nickel-silicide formation at the interface between the silicon and the nickel enhances stability and reduces the contact resistance. It was, therefore, found that nickel-silicide was suitable for high-efficiency solar cell applications. Cu was electroplated on the Ni layer by using a light induced plating method. The Cu electroplating solution was made up of a commercially available acid sulfate bath and additives to reduce the stress of the copper layer. In this paper, we investigated low-cost Ni/Cu contact formation by electro less and electroplating for crystalline silicon solar cells.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.511-512
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• 2010

• Proceedings of the Korean Vacuum Society Conference
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• 2009.08a
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• pp.226-226
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• 2009

• Proceedings of the Korean Vacuum Society Conference
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• 2004.02a
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• pp.172-172
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• 2004

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.3
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• pp.332-337
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• 2006

We prepared 100 nm-thick CoNi composite silicide on a 70 nm-thick polysilicon substrate. Composite silicide laye.s were formed by rapid thermal annealing(RTA) at the temperatures of $700^{\circ}C,\;900^{\circ}C,\;1000^{\circ}C$ for 40 seconds. A Focused ion beam (FIB) was used to make nano-patterns with the operation range of 30 kV and $1{\sim}100$ pA. We investigated the change of thickness, line width, and the slope angle of the silicide patterns by FIB. More easily made with the FIB process than with the conventional polycide process. We successfully fabricated sub-100nm etched patterns with FIB condition of 30kv-30pA. Our result implies that we may integrate nano patterns with our newly proposed CoNi composite silicides.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.230-234
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• 2009

It is significant technique to increase competitiveness that solar cells have a high energy conversion efficiency and cost effectiveness. When making high efficiency crystalline Si solar cells, evaporated Ti/Pd/Ag contact system is widely used in order to reduce the electrical resistance of the contact fingers. However, the evaporation process is no applicable to mass production because high vacuum is needed. Furthermore, those metals are too expensive to be applied for terrestrial applications. Ni/Cu/Ag contact system of silicon solar cells offers a relatively inexpensive method of making electrical contact. Ni silicide formation is one of the indispensable techniques for Ni/Cu/Ag contact sytem. Ni was electroless plated on the front grid pattern, After Ni electroless plating, the cells were annealed by RTP(Rapid Thermal Process). Ni silicide(NiSi) has certain advantages over Ti silicide($TiSi_2$), lower temperature anneal, one step anneal, low resistivity, low silicon consumption, low film stress, absence of reaction between the annealing ambient. Ni/Cu/Ag metallization scheme is an important process in the direction of cost reduction for solar cells of high efficiency. In this article we shall report an investigation of rapid thermal silicidation of nickel on silngle crystalline silicon wafers in the annealing range of $350-390^{\circ}C$. The samples annealed at temperatures from 350 to $390^{\circ}C$ have been analyzed by SEM(Scanning Electron Microscopy).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.198-201
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• 2002

In this paper, the dependence of Ni-silicide properties such as sheet resistance and cross-sectional profile on the dopants have been characterized. There was little dependence of sheet resistance on the used dopants such as As, P, $BF_{2}$ and $B_{11}$ just after RTP (Rapid Thermal Process). However, the silicide properties showed strong dependence on the dopants when thermal treatment was applied after formation of Ni-silicide. $BF_{2}$ implanted sample shows the best stable property, while $B_{11}$ implanted one was thermally unstable. The main reason of the excellent property of $BF_{2}$ sample is believed to be the retardation of Ni diffusion by the flourine.

• Journal of Powder Materials
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• v.6 no.2
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• pp.145-151
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• 1999

Nickel silicides ($Ni_5$Si$_2$, Ni$_2$Si and NiSi) have been synthesized by mechanical alloying (MA) of Ni-27.9at.9at%Si, Ni-33.3at% and Ni-50.0at% powder mixtures, respectively. From in situ thermal analysis, eash citical milling period for the formation of the three phases was observed to be 40.2, 34.9 and 57.5 min, at which there was a rapid increase in temperature. This indicates that rapid, self-propagating high-temperature synthesis (SHS) reactions were observed to produce the three phases during room-temperature high-energy ball milling of elemental powders. Each Ni silicide, Ni and Si, however, coexisted for an extended milling time even after the critical milling period. The powders mechanically alloyed after the critical period showed the rapid increase in microhardness. The Hv values were found to be higher than 1000kgf/mm$^2$. The formation of nickel silicides by mechanical alloying and the relevant reaction rates appeared to be influenced by the critical milling period and the heat of formation of the products involved ($Ni_5$Si$_2$$\rightarrow$-43.1kJ/mol.at., Ni$_2$Si$\rightarrow$-47.6kJ/mol.at., NiSi$\rightarrow$-42.4kJ/mol.at).

• Journal of the Korean Ceramic Society
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• v.43 no.4 s.287
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• pp.230-234
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• 2006

Metal-Induced Crystallization (MIC) of amorphous silicon (a-Si) using aluminum and nickel as catalysts were performed with a variation of metal thickness and temperature. Raman results showed that the crystallization of a-Si depended on the thickness of aluminum while not on nickel. Nickel that forms silicide nodules during annealing simply catalyzed the formation of crystalline silicon (c-Si) while aluminum was consumed and transferred during MIC, which resulted in more complex microstructural characteristics. Crystalline silicons after NIC had elongated shape with a twin along the long axis. Morphological change after Aluminum-Induced Crystallization (AIC) showed more equiaxial grains. The nucleation and growth mechanism of AIC was discussed.