• Korean Journal of Materials Research
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• v.17 no.9
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• pp.463-468
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• 2007

The interdiffusion characteristics of Cu-plug/Capping Layer/NiSi contacts were investigated. Capping layers were deposited on Ni/Si to form thermally-stable NiSi and then were utilized as diffusion barriers between Cu/NiSi contacts. Four different capping layers such as Ti, Ta, TiN, and TaN with varying thickness from 20 to 100 nm were employed. When Cu/NiSi contacts without barrier layers were furnace-annealed at $400^{\circ}C$ for 40 min., Cu diffused to the NiSi layer and formed $Cu_3Si$, and thus the NiSi layer was dissociated. But for Cu/Capping Layers/NiSi, the Cu diffusion was completely suppressed for all cases. But Ni was found to diffuse into the Cu layer to form the Cu-Ni(30at.%) solid solution, regardless of material and thickness of capping layers. The source of Ni was attributed to the unreacted Ni after the silicidation heat-treatment, and the excess Ni generated by the transformation of $Ni_2Si$ to NiSi during long furnace-annealing.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.187-187
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• 2010

In this study, we investigated the effect of electrodes on resistance switching of TaOx film. Pt, Ni, TiN, Ti and Al metal electrodes having the different oxidation degree were deposited on TaOx/Pt stack. Unipolar resistance switching behavior in Pt or Ni/TaOx/Pt MIM stacks was investigated, but bipolar resistance switching behavior in TiN, Ti or Al /TaOx/Pt MIM stacks was shown. We investigated that the voltage dependence of capacitance was decreased with higher oxidation degree of metal electrodes. Through the C-V results, we expected that linearity ($\alpha$) and quadratic ($\beta$) coefficient was reduced with an increase of interface layer between top electrode and Tantalum oxide. Transmission Electron Microscope (TEM) images depicted the thickness of interface layer formed with different oxidation degree of top electrode. Unipolar resistance switching behavior shown in lower oxidation degree of top electrode was expected to be generated by the formation of the conducting path in TaOx film. But redox reaction in interface between top electrode and Tantalum oxide may play an important role on bipolar resistance switching behavior exhibited in higher oxidation degree of top electrode. We expected that the resistance switching characteristics were determined by oxidation degree of metal electrodes.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.134-134
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• 2009

원자층 증착법을 이용하여 platinum group metal(Ru, Ir, Pt). metal nitride(TaN, TiN, AlN), 그리고 metal oxide($Al_2O_3$, $TiO_2$)을 증착하고, 미세구조와 공정 변수가 내산화성, 내부식성, 저항 및 온도저항계수에 미치는 영향을 연구하였다. proto-type의 전자저항막 제조를 통해 종래의 TaN 전자저항막에 비해 우수한 내부식성 및 내산화성을 가짐을 확인하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2006.10a
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• pp.67-68
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• 2006

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.171-171
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• 2003

공정기술의 향상으로 DRAM(dynamic random acess memory)의 고집적화가 이루어지고 있으며, 각 개별소자 및 셀 영역의 점유면적의 감소가 요구되어지고 있다. 따라서 기존에 사용하던 NO (Si$_3$N$_4$/SiO$_2$)박막보다 유전율이 높은 고유전물질에 대한 연구가 진행되고 있다. Ta$_2$O$_{5}$, $Y_2$O$_3$, HfO$_2$, ZrO$_2$,Nb$_2$O$_{5}$, BaTiO$_3$, SrTiO$_3$ 및 (BaSr)TiO등이 고유전물질로 연구되고 있는데 그 중 공정의 안정성, 누설전류의 우수성으로 인해 Ta$_2$O$_{5}$이 많이 연구되고 있다. 본 실험에서는 TiO$_2$가 8 mol%가 첨가된 Ta$_2$O$_{5}$의 열처리 온도에 따른 전기적, 유전특성을 살펴보려고 한다살펴보려고 한다

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.06a
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• pp.49-51
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• 1997

New complex perovskite compounds (Na0.5Sr0.5)(Ti0.5Nb0.5)O3, (Na0.5Sr0.5)(Zr0.5Ti0.5)O3 and (Na0.5Sr0.5)(Ti0.5Ta0.5)O3 have been prepared. The crystal structures of these compounds were determined by powder X-ray Rietveld analysis. The crystal structure of (Na0.5Sr0.5)(Ti0.5Nb0.5)O3 and (Na0.5Sr0.5)(Zr0.5Ta0.5)O3 was Pmmn, and that of (Na0.5Sr0.5)(Ti0.5Nb0.5)O3 was I4/mmm. All these compounds showed the superstructure due to the oxygen octahedron distortion. The selected bond distances and bond angles were calculated by the OFFER. The octahedron distortion for each sample, which was measured from the bond distances and bond angles, showed the following order: (Na0.5Sr0.5)(Z0.5Ta0.5)O3> (Na0.5Sr0.5)(Ti0.5Nb0.5)O3 > (Na0.5Sr0.5)(Ti0.5Ta0.5)O3. Dielectric properties were measured for the samples. In this study, the crystal structure and dielectric properties of the new complex perovskite structures and discussed.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.106-106
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• 2003

반도체 소자의 고집적화에 따라 채널길이와 배선선 폭은 점차 줄어들고, 이에 따라 단채널효과, 소스/드레인에서의 기생저항 증가 및 게이트에서의 RC 시간지연 증가 등의 문제가 야기되었다. 이를 해결하기 위하여 자기정렬 실리사이드화(SADS) 공정을 통해 TiSi2, CoSi2 같은 금속 실리사이드를 접촉 및 게이트 전극으로 사용하려는 노력이 진행되고 있다. 그런데 TiSi2는 면저항의 선폭의존성 때문에, 그리고 CoSi2는 실리사이드 형성시 과도한 Si소모로 인해 차세대 MOSFET소자에 적용하기에는 한계가 있다. 반면, NiSi는 이러한 문제점을 나타내지 않고 저온 공정이 가능한 재료이다. 그러나, NiSi는 실리사이드 형성시 NiSi/Si 계면의 산화와 거침성(roughness) 때문에 높은 누설 전류와 면저항값, 그리고 열적 불안정성을 나타낸다. 한편, 초고집적 소자의 배선재료로는 비저항이 낮고 electro- 및 stress-migration에 대한 저항성이 높은 Cu가 사용될 전망이다. 그러나, Cu는 Si, SiO2, 실리사이드로 확산·반응하여 소자의 열적, 전기적, 기계적 특성을 저하시킨다. 따라서 Cu를 배선재료로 사용하기 위해서는 확산방지막이 필요하며, 확산방지재료로는 Ti, TiN, Ta, TaN 등이 많이 연구되고 있다.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.05a
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• pp.50-51
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• 2000

• Journal of the Korean Ceramic Society
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• v.26 no.3
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• pp.297-304
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• 1989

The dielectric properties of SrTiO3 GBL Capacitor have been investigaetd as a function of the second heat treatment time and the amount of Ta. The grain size of semiconductive SrTiO3 after sintering at 1,46$0^{\circ}C$ for 4 hours in N2/H2 atmosphere increased as the amount of Ta increased, and then decreased as the amount of Ta exceed 0.01 mole. Also, the dielectric constant after the second heat treatment showed the same tendency. When the semiconductive SrTiO2 was second heat treated at 1,10$0^{\circ}C$ in air with varying time, the dielectric constant increased as the second heat treatment time increased up to 60 minutes, and then decreased as the time became longer than 60 minutes.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.335-337
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• 1989

The Charcteristics of the HCD ion plating system for TiN coating was Investigated. 1-V curvet of the HCD ( hollow cathode discharge ), radiation temperatures of the Ta tube and the Ti pool and the electron density and the temperature of the generated plasma are shown. The preferred orientation and the micro-hardness of coatings performed by HCD process are studied.