• Title/Summary/Keyword: Epitaxial thin film

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A Study on the Formation fo Epitaxial $CoSi_2$ Thin Film using Co/Ti Bilayer (Co/Ti이중박막을 이용한 $CoSi_2$에피박막형성에 관한 연구)

  • Kim, Jong-Ryeol;Bae, Gyu-Sik;Park, Yun-Baek;Jo, Yun-Seong
    • Korean Journal of Materials Research
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    • v.4 no.1
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    • pp.81-89
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    • 1994
  • Ti film of lOnm thickness and Co film of 18nm thickness were sequentially e-heam evaporated onto Si (100) substrates. Metal deposited samples were rapidly thermal-annt.aled(KTA) in thr N1 en vironment a t $900^{\circ}C$ for 20 sec. to induce the reversal of metal bilayer, so that $CoSi_{2}$ thin films could be formed. The sheet resistance measured by the 4-point probe was 3.9 $\Omega /\square$This valur was maintained with increase in annealing time upto 150 seconds, showing high thermal stab~lity. Thc XRII spectra idrn tified the silicide film formed on the Si substrate as a $CoSi_{2}$ epitaxial layer. The SKM microgr;iphs showed smooth surface, and the cross-sectional TKM pictures revealed that the layer formed on the Si substrate were composed of two Co-Ti-Si alloy layers and 70nm thick $CoSi_{2}$ epl-layer. The AES analysis indicated that the native oxide on Si subs~rate was removed by TI ar the beginning of the RTA, and Ihcn that Co diffused to clean surface of Si substrate so that epitaxial $CoSi_{2}$ film could bt, formed. In thc rasp of KTA at $700^{\circ}C$. 20sec. followed by $900^{\circ}C$, 20sec., the thin film showed lower sheet resistance, but rough surface and interface owing to $CoSi_{2}$ crystal growth. The application scheme of this $CoSi_{2}$ epilayer to VLSI devices and the thermodynarnic/kinetic mechan~sms of the $CoSi_{2}$ epi-layer formation through the reversal of Co/Ti bdayer were discussed.

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Initial Growth Mode and Epitaxial Growth of AIN Thin Films on $Al_2O_3(0001)$ Substrate by DC Faced Target Sputtering

  • Kim, Jin-Woo;Kang, Kwang-Yong;Lee, Su-Jae
    • The Korean Journal of Ceramics
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    • v.5 no.4
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    • pp.368-370
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    • 1999
  • Using DC faced target sputtering method we grow AIN the films on the $Al_2O_3$(0001) substrate with varying thickness(17$\AA$-1000$\AA$). We measured x-ray diffraction(XRD) profiles by synchrotron radiation($\lambda$=1.12839 $\AA$) with four circle diffractometer. The full width half maximum(FWHM) of rocking curve for the AIN (0002) diffraction of the film grown at $500^{\circ}C$ was $0.029^{\circ}$. Also, we confirmed that the stress between AIN thin film and $Al_2O_3$(0001) substrate was reduced as increasing AIN film thickness, and the critical thickness of 400~500 $\AA$, defined as a lattice constant in the film agrees with that in a bulk without stress, was obtained.

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Characteristics of BSCCO Thin Film by Layer-by-layer Deposition (순차 스퍼터 법에 의한 BSCCO 박막의 특성)

  • Lee, Hee-Kab;Park, Yong-Pil;Kim, Gwi-Yeol;Oh, Geum-Gon;Choi, Woon-Shik;Cho, Choon-Nam
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.281-283
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    • 2001
  • $Bi_{2}Sr_{2}CuO_{x}$(Bi-2201) thin films were fabricated by atomic layer-by-layer deposition using an ion bearn sputtering method. 10 wt% and 90 wt% ozone mixed with oxygen were used with ultraviolet light irradiation to assist oxidation. At early stages of the atomic layer by layer deposition. two dimensional epitaxial growth which covers the substrate surface would be suppressed by the stress and strain caused by the lattice misfit. then three dimensional growth takes place. Since Cu element is the most difficult to oxidize. only Sr and Bi react with each other predominantly. and forms a buffer layer on the substrate in an amorphous-like structure. which is changed to $SrBi_{2}O_{4}$ by in-situ anneal.

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Epitaxial Growth of BSCCO Thin film Fabricated by Layer-by-layer Sputtering

  • Yang, Sung-Ho;Park, Yong-Pil;Lee, Hee-Kab
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.212-217
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    • 2000
  • Bi$_2$Sr$_2$CuO$_{x}$(Bi-2201) thin films have been fabricated by atomic layer-by-layer deposition using ion beam sputtering(IBS) process. During the deposition, 14 wt%-ozone/oxygen mixture gas of typical pressure of 5.0$\times$10$^{-5}$ Torr is supplied with ultraviolet light irradiation for oxidation. XRD and RHEED investigations reveal that a buffer layer with compositions different from Bi-2201 is formed at the early deposition stage of less than 10 units cell and then Bi-2201 oriented along the c-axis is grown.n.

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Characteristics of BSCCO Thin Film by Layer-by-layer Deposition (순차 스퍼터 법에 의한 BSCCO 박막의 특성)

  • 이희갑;박용필;김귀열;오금곤;최운식;조춘남
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.281-283
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    • 2001
  • Bi$_2$Sr$_2$CuO$\_$x/(Bi-2201) thin films were fabricated layer-by-layer deposition using an ion beam sputtering method. 10 wt% and 90 wt% ozone mixed with oxygen were used ultraviolet light irradiation to assist oxidation. At early stages of the atomic layer by layer deposition, two dimensional epitaxial growth which covers the substrate surface would be suppressed by the stress and strain caused by the lattice misfit, then three dimensional growth takes place. Since Cu element is the most difficult to oxidize, only Sr and Bi react with each other predominantly, and forms a buffer layer on the substrate in an amorphous-like structure, which is changed to SrBi$_2$O$_4$ by in-situ anneal.

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Synthesis and Characterization of Novel Rare-earth Oxides Precursors

  • Lee, Euy Jin;Park, Bo Keun;Chung, Taek-Mo;Kim, Chang Gyoun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.366.1-366.1
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    • 2014
  • The rare-earth oxides M2O3 (M=La, Pr, Gd) are good insulators due to their large band gap (3.9eV for Pr2O3, 5.6eV for Gd2O3), they have high dielectric constants (Gd2O3 K=16, La2O3 K=27, Pr2O3 K=26-30) and, compared to ZrO2 and HfO2, they have higher thermodynamic stability on silicon making them very attractive materials for high-K dielectric applications. Another attractive feature of some rare-earth oxides is their relatively close lattice match to that of silicon, offering the possibility of epitaxial growth and eliminating problems related to grain boundaries in polycrystalline films. Metal-organic chemical vapor deposition (MOCVD) has been preferred to PVD methods because of the possibility of large area deposition, good composition control and excellent conformal step coverage. Herein we report on the synthesis of rare-earth oxide complexes with designed alkoxide and aminoalkoxide ligand. These novel complexes have been characterized by means of FT-IR, elemental analysis, and thermogravimetric analysis (TGA).

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Quantitative Evaluation of Dislocation Density in Epitaxial GaAs Layer on Si Using Transmission Electron Microscopy

  • Kim, Kangsik;Lee, Jongyoung;Kim, Hyojin;Lee, Zonghoon
    • Applied Microscopy
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    • v.44 no.2
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    • pp.74-78
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    • 2014
  • Dislocation density and distribution in epitaxial GaAs layer on Si are evaluated quantitatively and effectively using image processing of transmission electron microscopy image. In order to evaluate dislocation density and distribution, three methods are introduced based on line-intercept, line-length measurement and our coding with line-scanning method. Our coding method based on line-scanning is used to detect the dislocations line-by-line effectively by sweeping a thin line with the width of one pixel. The proposed method has advances in the evaluation of dislocation density and distribution. Dislocations can be detected automatically and continuously by a sweeping line in the code. Variation of dislocation density in epitaxial GaAs films can be precisely analyzed along the growth direction on the film.

Epitaxial Growth of BSCCO Films by IBS Method (IBS법에 의한 BSCCO 박막의 에피택셜 성장)

  • 양승호;박용필
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.05a
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    • pp.627-630
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    • 2002
  • Bi$_2$Sr$_2$CuOx(Bi-2201) thin films were fabricated by atomic layer-by-layer deposition using an ion bean sputtering method. 10 wt% and 90 wt% ozone mired with oxygen were used with ultraviolet light irradiation to assist oxidation. XRD and RHEED investigations revealed that a buffer layer is formed at the early stage of deposition (less than 10 unit cell), and then c-axis oriented Bi-2201 grows on top of it.

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