• Title/Summary/Keyword: Capacitance of Thin Films

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Electrical Properties of Ba0.66Sr0.34TiO3 Thin Films Fabricated by a Seed-layer Process (Seed-layer 공정을 이용한 Ba0.66Sr0.34TiO3박막의 제조 및 전기적 특성 연구)

  • 최덕영;박철호;손영국
    • Journal of the Korean Ceramic Society
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    • v.40 no.2
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    • pp.198-205
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    • 2003
  • $Ba_{0.66}Sr_{0.34}TiO_3$ thin films and seed-layers were deposited on $Pt/Ti/SiO_2/Si$substrate by R.F. magnetron sputtering method. Effects of various substrate temperature conditions on electrical properties (such as capacitance and leakage current) of BST thin films were studied. The effect of seed-layer was also studied. When seed-layer was inserted between BST and Pt, the crystallization of the BST thin films was considerably improved and the processing temperature was lowered. Compared to the pure BST thin films, dielectric constant, dielectric loss, and leakage current of BST thin films deposited on the seed-layer were considerably improved. It could be revealed that electrical properties are influenced by the substrate temperatures of BST thin films and are enhanced by the seed-layer.

Preparation and Characterization of Sol-Gel Derived High-k $SrTa_2O_6$ Thin Films

  • Park, Kwang-Hun;Jeon, Ho-Seung;Kim, Zee-Won;Park, Byung-Eun;Kim, Chul-Ju
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.198-199
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    • 2006
  • $SrTa_2O_6$(STA) thin films were fabricated by sol-gel method. The films annealed below $700^{\circ}C$, showed amorphous phase and crystallization phase was observed after annealing over $800^{\circ}C$. From high frequency capacitance-voltage measurements, 24nm thick STA thin film annealed at $900^{\circ}C$, has an EOT of 5.7nm and a dielectric constant of 16. Leakage current characteristics were improved by the insertion of chemical oxide between STA and Si. Leakage current densities are around $3.5{\times}10^{-7}A/cm^2$ at 5V for the structure inserted chemical oxide but $1.4{\times}10^{-6}A/cm^2$ at 5V without chemical oxide.

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Effect of Annealing Conditions on $Ta_2$$O_5$ Thin Films Deposited By PECVD System (열처리 조건이 PECVD 방식으로 증착된 $Ta_2$$O_5$ 박막 특성에 미치는 영향)

  • 백용구;은용석;박영진;김종철;최수한
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.8
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    • pp.34-41
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    • 1993
  • Effect of high temperature annealing conditions on Ta$_{2}O_{5}$ thin films was investigated. Ta$_{2}O_{5}$ thin films were deposited on P-type silicon substrates by plasma-enhanced chemical vapor deposition (PECVD) using tantalum ethylate. Ta(C$_{2}H_{5}O)_{5}$, and nitrous oxide. N$_{2}$O. The microstructure changed from amorphous to polycrystalline above 700.deg. C annealing temperature. The refractive index, dielectric onstant and leakage current of the film increased as annealing temperature increased. However, annealing in oxygen ambient reduced leakage currents and dielectric constant due to the formation of interfacial SiO$_{2}$ layer. By optimizing annealing temperature and ambient, leakage current lower than 10$^{-8}$ A/cm$^{2}$ and maximum capacitance of 9 fF/${\mu}m^{2}$ could be obtained.

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Humidity Sensitive Properties of $V_2O_5$-added $TiO_2$ Ceramics ($V_2O_5$ 첨가에 따른 $TiO_2$ 세라믹스의 감습특성)

  • Hyun, You-Do
    • Proceedings of the KIEE Conference
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    • 2008.05a
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    • pp.161-163
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    • 2008
  • $TiO_2-V_2O_5$ sol was fabricated using sol-gel method and $TiO_2-V_2O_5$, thin films were fabricated using dip-coating method. $V_2O_5$ sol was added 0.01mole, 0.03mole, 0.05mole into $TiO_2$ sol. Capacitance of thin films decreased with increasing $V_2O_5$ additive and it increased largest at 0.01mole. Because adsorption time and desorption time of thin films was about 2 minutes 40 seconds and about 3 minutes 40 seconds respectively, adsorption time was faster about 1 minutes than desorption time.

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Properties of Spin-On-Glass Siloxane Thin Films Fluorine-doped by CF$_4$ Plasma (CF$_4$ 플라즈마 처리로 불소를 첨가한 실록산 Spin-On-Glass 박막의 특성)

  • 김현중;김기호
    • Journal of the Korean institute of surface engineering
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    • v.34 no.3
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    • pp.258-263
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    • 2001
  • Siloxane thin films were fabricated on a silicon wafer by spin-coating using a siloxane solution made by the sol-gel process. Fluorine was doped using$ CF_4$ plasma treatment. The film was then annealed in-situ state in the nitrogen atmosphere. In order to examine the influence of annealing and fluorine doping on the siloxane thin film, thermogravimetric-differential thermal analysis (TG-DTA), Fourier transform-infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) were used and the dielectric constant was determined by the high-frequency capacitance-voltage method. Stable siloxane films could be obtained by in-situ annealing in a nitrogen atmosphere after $CF_4$ plasma treatment, and the dielectric value of the film was $\varepsilon$ 2.5.

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Properties with Annealing Temperature of SCT Ceramic Thin Film (SCT 세라믹 박막의 열처리온도 특성)

  • Kim, J.S.;Cho, C.N.;Oh, Y.C.;Shin, C.G.;Choi, W.S.;Kim, C.H.;Lee, J.U.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.566-569
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    • 2002
  • The $(Sr_{0.9}Ca_{0.1})TiO_3$(SCT) thin films are deposited on Pt-coated electrode (Pt/TiN/$SiO_2$/Si) using RF sputtering method. The maximum dielectric constant of SCT thin film is obtained by annealing at $600[^{\circ}C]$. The temperature properties of the dielectric loss have a value within 0.02 in temperature ranges of $-80{\sim}+90[^{\circ}C]$. The capacitance characteristics had a stable value within ${\pm}4[%]$. The drastic decrease of dielectric constant and increase of dielectric loss in SCT thin films is observed above 200[kHz].

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Alcohol Gas Sensors using Spray-coated Carbon Nanotube Thin Film (스프레이 코팅된 탄소나노튜브 박막을 이용한 알코올 가스 센서)

  • Kim, Seong-Jeen
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.9
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    • pp.783-788
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    • 2008
  • We suggest a CNT-based gas sensor for breath alcohol measurement. The sensor was composed of single-walled carbon nanotubes (SWCNTs) thin film on flexible PES (polyethersulfone) substrate, and the SWCNTs thin film was formed by multiple spray-coating with SWCNTs solution which was well-dispersed, highly controlled and functionalized in ethanol solvent. In this work, three types of SWCNTs thin films were deposited with changes in the number of spray-coatings to 20, 40 and 60 times in order to compare electrical response properties of the SWCNTs thin films. from the fabricated sensors, conductance and capacitance responses were measured and discussed. Alcohol gas sensors have been commercialized widely as gauge for breath alcohol measurement which is applicable to checking whether car drivers are drinking-driving or not. Our alcohol gas sensors showed good sensitivity and linearity even at room temperature.

Fabrication of DLPC LB films with MIS structure and I-V characteristics (MIS 구조의 DLPC LB 막의 제작과 전압-전류 특성)

  • 이우선;정용호;정종상;손경춘;김상용;장의구;이경섭
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.155-158
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    • 1998
  • MLS capacitor with lipid ultra thin films were deposited by Langmuir-Blodgett (LB) method on the sillicon wafer. The current versus voltage and capacitance versus voltage relationships are depend on the applied voltage, electrode area and electrode materials. LB films deposited were made of L-$\alpha$-DLPC, the 1 layer's thickness of 35$\AA$ was measured by ellipsometer. And MLS capacitor with different electrode materials, the work function of these materials was investigated to increase the leakage current. The result indicated the lower leakage current and very high saturation value of capacitance was reached within 700-800 pF when the two electrode was Ag. And $\varepsilon$$_1$, $\varepsilon$$_2$ versus photon energy showed good film formation.

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Deposition of Ferroelectric PB(Zr0.52Ti0.48)O3 Films on Platinized Silicon Using Nd:YAG Laser

  • Im, Hoong-Sun;Kim, Sang-Hyeob;Choi, Young-Ku;Lee, Kee-Hag;Jung, Kwang-Woo
    • Bulletin of the Korean Chemical Society
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    • v.18 no.1
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    • pp.56-61
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    • 1997
  • Lead zirconate titanate (PZT) thin fills were deposited onto the Pt/Ti/SiO2/Si substrate by the pulsed laser deposition with the second harmonic wavelength (532 nm) of Nd:YAG laser. In order to determine the optimum conditions for the film deposition, the phase of the films were investigated as functions of ambient oxygen pressure, substrate temperature, and laser fluence. Also the chemical composition analysis was conducted for the PZT films deposited under various ambient oxygen pressure. When the distance between substrate and bulk PZT target is set to 20 mm, the optimum conditions have been determined to be 3 torr of oxygen pressure, 1.5 J/cm2 of laser fluence, and 823-848(±10) K range of substrate temperature. At these conditions, perovskite phase PZT films were obtained on platinized silicon. The chemical composition of the films is very similar to that of PZT bulk target. The physical structure of the deposited films analyzed by scanning electron microscopy shows a columnar morphology perpendicular to the substrate surface. Capacitance-Voltage hysteresis loop measurements show also a typical characteristics of ferroelectric thin film. The dielectric constant is found to be 528 for the 0.48 μm thickness of PZT thin film.

ECR-PECVD PZT Thin Films for the Charge Storage Cpacitor of ULSI DRAMs (ECR-PECVD법을 사용한 ULSI DRAM 용 PZT 박막 제조)

  • 김재환;신중식;김성태;노광수;위당문;이원종
    • Journal of the Korean Vacuum Society
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    • v.4 no.S1
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    • pp.145-150
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    • 1995
  • PZT thin films were fabricated on Pt/Ti/SiO2/Si substrates at $500^{\circ}C$ by ECR-PECVD for the application to the charge storage capacitor of ULSI DRAMs. Perovskite single phase PZT films were obtained by controling the film compositional ratio Pb/(Zr+Ti) close to 1. The anion concentrations in the PZT films were successfully controlled by adjusting the flow rates of each MO sources. Capacitance of a typical 94 nm thick PZT film prepared at $500^{\circ}C$ in this work was about 5.3 uF/$\textrm{cm}^2$, which corresponds to the equivalent SiO2 thickness of 0.65nm.

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