• Title/Summary/Keyword: Nucleation density

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Metalorganic Chemical Vapor Deposition of Copper Films on TiN Substrates Using Direct Liquid Injection of (hfac)Cu(vtmos) Precursor ((hfac)Cu(vtmos)의 액체분사법에 의한 TiN 기판상 구리박막의 유기금속 화학증착 특성)

  • Jun, Chi-Hoon;Kim, Youn-Tae;Kim, Dai-Ryong
    • Korean Journal of Materials Research
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    • v.9 no.12
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    • pp.1196-1204
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    • 1999
  • We have carried out copper MOCVD(metalorganic chemical vapor deposition) onto the reactive sputtered PVD-TiN and rapid thermal converted RTP-TiN substrates using direct liquid injection for effective delivery of the (hfac)Cu(vtmos) [$C_{10}H_{13}O_{5}CuF_{6}$Si: 1,1,1,5,5,5-hexafluoro-2,4- pentadionato (vinyltrimethoxysilane) copper (I)] precursor. Especially, the influences of deposition conditions and the substrate type on growth rate, crystal structure, microstructure, and electrical resistivity of copper deposits have been discussed. It is found that the film growth with 0.2ccm precursor flow rate become mass-transfer controlled up to Ar flow rate of 200sccm and pick-up rate controlled at a vaporizer above 1.0Torr reactor pressure. The surface-reaction controlled region from 155 to 225$^{\circ}C$ at 0.6Torr reactor pressure results in the apparent activation energies of 12.7~14.1kcal/mol, and above 224$^{\circ}C$ the growth rate with $H_2$ addition could be improved compared to the pure Ar carrier. The Cu/RTP-TiN structures which have high copper nucleation density in initial stage of growth show more pronounced (111) preferred orientations and lower electrical resistivities than those on PVD-TiN. The variation of electrical resistivity with substrate temperature reflects the three types of film microstructure changes, showing the lowest value for the deposit at 165$^{\circ}C$ with small grains of good contacts.

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Properties of Perovskite Materials and Devices Fabricated Using the Solvent Engineered One-Step Spin Coating Method (단일 스텝 스핀 코팅 방법에서 증발 제어 공정 변경에 따른 페로브스카이트 박막 물성 및 태양 전지 소자 특성 변화에 관한 연구)

  • Oh, Jungseock;Kwon, Namhee;Cha, DeokJoon;Yang, JungYup
    • New Physics: Sae Mulli
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    • v.68 no.11
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    • pp.1208-1214
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    • 2018
  • The one-step spin coating method is reported as an excellent thin film process because it can be easily used to fabricate high-quality methyl-ammonium lead tri-iodide ($MAPbI_3$) perovskite layers. One of the important things in the one-step spin coating method towards obtaining high-quality $MAPbI_3$ layers is the anti-solvent (AS) engineering, which consists of an one-step deposition of the $MAPbI_3$ film and dripping of the AS. The properties of the $MAPbI_3$ layer were found to be strongly influenced by the amount, dispensing speed, and spraying time of the AS solution. The $MAPbI_3$ solution was prepared by dissolving lead iodide and methyl-ammonium iodide in N,N-dimethylformamide and adding N,N-dimethyl sulfoxide. Diethyl ether (DE) was used for the AS solution. The results indicate that a $MAPbI_3$ layer appropriately sprayed with DE is beneficial for improving film quality and device efficiency because nucleation of $MAPbI_3$ layer is affected by the characteristics of DE, which affect the film's crystallinity, density, and surface morphology. The $MAPbI_3$ layer, which was optimized by using 0.7 mL of DE, a 3.03 mL/sec dispensing speed, and a 7 second time to spray after spinning showed the best efficiency of 13.74%, which was reproducible.