• Title/Summary/Keyword: Preferential orientation

Search Result 87, Processing Time 0.028 seconds

Deposition Characteristics of AlN Thin Films Prepared by RF Magnetron Sputtering (RF 마그네트론 스퍼터링에 의해 제조된 AlN 박막의 증착 특성)

  • Song, Jong-Han;Chun, Myoung-Pyo;Choi, Duck-Kyun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.25 no.12
    • /
    • pp.969-973
    • /
    • 2012
  • AlN thin films were deposited on p-type Si(100) substrates by RF magnetron sputtering method. This study showed the change of the preferential orientation of AlN thin films deposition with the change of the deposition conditions such as sputtering pressure and Ar/N2 gas ratio in chamber. It was identified by X-ray diffraction patterns that AlN thin film deposited at low sputtering pressure has a (002) orientation, however its preferred orientation was changed from the (002) to the (100) orientation with increasing sputtering pressure. Also, it was observed that the properties of AlN thin films such as thickness, grain size and surface roughness were largely dependent on Ar/$N_2$ gas ratio and a high quality thin film could be prepared at lower nitrogen concentration. AlN thin films were investigated relationship between preferential orientation and deposition condition by using XRD, FE-SEM and PFM.

Effects of Physico-chemical Factors of Sol on the Degree of Preferred Orientation in $Pb(Mg, Zn)_{1/3}Nb_{2/3}O_3$ Thin Films (Sol의 물리화학적 변수들이 $Pb(Mg, Zn)_{1/3}Nb_{2/3}O_3$ 박막의 우선 배향성에 미치는 효과)

  • 조문규;장현명;김광수
    • Journal of the Korean Ceramic Society
    • /
    • v.32 no.3
    • /
    • pp.305-312
    • /
    • 1995
  • Thin films of Pb(Mg, Zn)1/3Nb2/3O3 were fabricated by spin coating the Pb-Mg-Zn-Nb-O complex alkoxide sols on(111) Pt-coated MgO (100) planes. It was observed that the content of H2O and the rheological characteristics of sol greatly influenced the orientation of perovskite grains after thin-film formation. A strong preferential orientation of (100)-type planes of the perovskite grains was obtained for the sol aged for 15 days with the molar ratio of H2O to total metal alkoxides=2. As small angle X-ray scattering experiment in the Porod region was performed to correlate the observed preferential orientation with the network structure of precursors at various stage of aging. It was shown that the degree of branching of the Pb-Mg-Zn-Nb-O precursor chain had a direct effect on the preferred oreintation, and weakly branched precursor systems led to highly oriented grains after thin-film formation.

  • PDF

Influence of surface roughness of ZnO layer on the growth of polycrystalline Si layer via aluminum-induced layer exchange process

  • Choi, Sung-Kuk;Chang, Won-Beom;Jung, Soo-Hoon;Hara, Kosuke;Watanabe, Haruna;Usami, Noritaka;Chang, Ji-Ho
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.40 no.8
    • /
    • pp.692-697
    • /
    • 2016
  • This study investigated the effect of surface roughness of zinc oxide (ZnO) layer on the growth of polycrystalline Si layer via an Al-induced layer exchange process. It was found that the growth rate, grain size, crystallization fraction, and preferential orientation of the polycrystalline Si layer were strongly influenced by the surface roughness of the underlying ZnO layer. As the roughness of the ZnO surface increased, a higher growth rate (~40 min) and preferential Si (100) orientation were obtained because of the spatial concentration fluctuations in the Al-Si alloy, induced by the surface roughness of the underlying ZnO layer.

Growth Behavior of Nanocrystalline CrN Coatings by Inductively Coupled Plasma (ICP) Assisted Magnetron Sputtering (유도결합 플라즈마를 이용한 마그네트론 스퍼터링으로 증착된 나노결정질 CrN 코팅막의 성장)

  • Seo, Dae-Han;Chun, Sung-Yong
    • Journal of the Korean Ceramic Society
    • /
    • v.49 no.6
    • /
    • pp.556-560
    • /
    • 2012
  • Nanocrystalline CrN coatings were deposited by DC and ICP-assisted magnetron sputtering on Si (100) substrates. The influences of the ICP power on the microstructural and crystallographic properties of the coatings were investigated. For the generation of the ICP, radio frequency was applied using a dielectric-encapsulated coil antenna installed inside the deposition chamber. As the ICP power increased from 0 to 500W, the crystalline grain size decreased. It is believed that the decrease in the crystal grain size at higher ICP powers is due to resputtering of the coatings as a result of ion bombardment as well as film densification. The preferential orientation of CrN coatings changed from (111) to (200) with an increase in the ICP power. The ICP magnetron sputtering CrN coatings showed excellent surface roughness compared to the DC magnetron sputtering coatings.

Effect of ligand orientation on hepatocyte attachment onto the poly(N-p-vinyl benzyl-o-$\beta$-D-galactopyranosyl-D-gluconamide)

  • Jo, Jong-Su;Goto, M.;Kobayashi, A.;Kobayashi, K.;Akaike, T.
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1996 no.05
    • /
    • pp.123-125
    • /
    • 1996
  • The orientation effect of galactose ligand on hepatocyte attachment was investigated. Poly(N-p-vinyl benzyl-o-${\beta}$-D-galactopyranosyl-D-gluconamide) (PVLA), a ${\beta}$-galactose-carrying styrene homo-polymer, was used as a model ligand for the asialoglycoprotein receptors on hepatocytes. PYVA was transferred onto the poly(${\gamma}$-benzyl L-glutamate)(PBLG) or PBLG/ poly(ethylene glycol)(PEG)/PBLG Langmuir-Blodgett (LB) films as the monolayer level. The dichroic fluorescence values of confocal microscope indicated that the PVLA transferred onto the LB films was located with a preferential orientation of its molecular axes with regard to the direction of the a-helix of polypeptide. Hepatocyte recognized well-oriented galactose moieties of the surface of PVLA through asialoglycoprotein receptors.

  • PDF

DNA Light-strand Preferential Recognition of Human Mitochondria Transcription Termination Factor mTERF

  • Nam, Sang-Chul;Kang, Chang-Won
    • BMB Reports
    • /
    • v.38 no.6
    • /
    • pp.690-694
    • /
    • 2005
  • Transcription termination of the human mitochondrial genome requires specific binding to termination factor mTERF. In this study, mTERF was produced in E. coli and purified by two-step chromatography. mTERF-binding DNA sequences were isolated from a pool of randomized sequences by the repeated selection of bound sequences by gel-mobility shift assay and polymerase chain reaction. Sequencing and comparison of the 23 isolated clones revealed a 16-bp consensus sequence of 5'-GTG$\b{TGGC}$AGANCCNGG-3' in the light-strand (underlined residues were absolutely conserved), which nicely matched the genomic 13-bp terminator sequence 5'-$\b{TGGC}$AGAGCCCGG-3'. Moreover, mTERF binding assays of heteroduplex and single-stranded DNAs showed mTERF recognized the light strand in preference to the heavy strand. The preferential binding of mTERF with the light-strand may explain its distinct orientation-dependent termination activity.

Properties of VN Coatings Deposited by ICP Assisted Sputtering: Effect of ICP Power

  • Chun, Sung-Yong
    • Journal of the Korean Ceramic Society
    • /
    • v.54 no.1
    • /
    • pp.38-42
    • /
    • 2017
  • Vanadium nitride (VN) coatings were deposited using inductively coupled plasma (ICP) assisted sputtering at different ICP powers. Microstructural, crystallographic and mechanical characterizations were performed by FE-SEM, AFM, XRD and nanoindentation. The results show that ICP has significant effects on coating's microstructure, structural and mechanical properties of VN coatings. With an increase in ICP power, coating microstructure evolved from a porous columnar structure to a highly dense one. Single- phase cubic (FCC) VN coatings with different preferential orientations and residual stresses were obtained as a function of ICP power. Average crystal grain sizes of single phase cubic (FCC) VN coatings were decreased from 10.1 nm to 4.0 nm with an increase in ICP power. The maximum hardness of 28.2 GPa was obtained for the coatings deposited at ICP power of 200 W. The smoothest surface morphology with Ra roughness of 1.7 nm was obtained in the VN coating sputtered at ICP power of 200 W.