• 제목/요약/키워드: $BaTiO_3$ thin film

검색결과 203건 처리시간 0.03초

자장강화된 유도결합 플라즈마를 이용한 (Ba, Sr) $TiO_3$박막의 식각 특성 연구 (The Etching Characteristics of (Ba, Sr) $TiO_3$Thin Films Using Magnetically Enhanced Inductively Coupled Plasma)

  • 민병준;김창일
    • 한국전기전자재료학회논문지
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    • 제13권12호
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    • pp.996-1002
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    • 2000

  • Ferroelectric (Ba, Sr) TiO$_3$(BST) thin films have attracted much attention for use in new capacitor materials of dynamic random access memories (DRAMs). In order to apply BST to the DRAMs, the etching process for BST thin film with high etch rate and vertical profile must be developed. However, the former studies have the problem of low etch rate. In this study, in order to increase the etch rate, BST thin films were etched with a magnetically enhanced inductively coupled plasma(MEICP) that have much higher plasma density than RIE (reactive ion etching) and ICP (inductively coupled plasma). Experiment was done by varying the etching parameters such as CF$_4$/(CF$_4$+Ar) gas mixing ratio, rf power, dc bias voltage and chamber pressure. The maximum etch rate of the BST films was 170nm/min under CF$_4$/CF$_4$+Ar) of 0.1, 600 W/-350 V and 5 mTorr. The selectivities of BST to Pt and PR were 0.6 and 0.7, respectively. Chemical reaction and residue of the etched surface were investigated with X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS).

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4H-SiC에 증착된 BST 박막의 열처리 효과에 따른 구조적, 전기적 특성 (Effect of post annealing on the structural and electrical properties of $Ba_{0.5}Sr_{0.5}TiO_3$ films deposited on 4H-SiC)

  • 이재상;조영득;방욱;김상철;김남균;구상모
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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    • pp.196-196
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    • 2008

  • We have investigated that the effect of post annealing on the structural and electrical properties of $Ba_{0.5}Sr_{0.5}TiO_3$ thin films. The BST thin films were deposited on n-type 4H-silicon carbide(SiC) using pulsed laser deposition (PLD). The deposition was carried out in oxygen ambient 100mTorr for 5 minutes, which results in about 300nm-thick BST films. For the BST/4H-SiC, 200nm thick silver was deposited on the BST films bye-beam evaporation. The X-ray diffraction patterns of the BST films revealed that the crystalline structure of BST thin films has been improved after post-annealing at $850^{\circ}C$ for 1 hour. The root mean square (RMS) surface roughness of the BST film measured by using a AFM was increased after post-annealing from 5.69nm to 11.49nm. The electrical properties of BST thin film were investigated by measuring the capacitance-voltage characteristics of a silver/BST/4H-SiC structure. After the post-annealing, dielectric constant of the film was increased from 159.67 to 355.33, which can be ascribed to the enhancement of the crystallinity of BST thin films.

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졸-겔법에 의한 강유전 BST 박막의 제조 및 특성(II) - 초음파의 효과 (Fabrication and Properties of ferroelectric BST thin films prepared by sol-gel method (II) - effect of ultrasound on properties of thin film)

  • 이진홍;박병옥;이승엽
    • 한국결정성장학회지
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    • 제11권6호
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    • pp.252-258
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    • 2001

  • ($Ba_{0.7}Sr_{0.3})TiO_3$박막을 ITO-coated glass 기판위에 spin-coating법으로 제조하였다. 제조된 용액을 초음파 bath 내에서 초음파 처리하여 균일화를 촉진시킨 후 박막을 제조하여 초음파 처리하지 않은 용액으로 제조한 박막과의 비교를 통하여 초음파 효과를 알아보았다. 용액의 초음파 처리로 박막의 결정화 온도를 다소 낮추었으며 박막의 표면이 보다 균일하고 치밀화되었고 거칠기도 8.4nm에서 5.6nm로 더 낮아졌다. 그리고 박막의 투광성 및 전기적 특성 또한 용액의 초음파 처리로 인하여 향상되었다.

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유전체 멤브레인에 의해 열 차단된 비냉각 초전형 박막 (Ba,Sr)TiO3 적외선 검지기 (Uncooled pyroelectric thin-film (Ba,Sr)$TiO_3$ infrared detector thermally isolated by dielectric membrane)

  • 김진섭;이재신;이정희;이용현
    • 대한전자공학회논문지SD
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    • 제38권3호
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    • pp.75-75
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    • 2001

  • Si₃N₄/SiO₂/Si₃N₄ 멤브레인에 의해 실리콘 기판으로부터 열차단된 비냉각 초전형 박막 (Ba,Sr)TiO₃ 적외선 검지기를 제작하고, 적외선 검지기의 특성을 논의하였다. 25℃의 공기중에서 쵸핑주파수가 1 ㎐일 때 적외선 검지기는 약 168.8 V/W의 비교적 높은 전압 감응도를 나타내었으나, 매우 작은 신호대잡음비 때문에 약 2.6×10⁴㎝·㎐/sup 1/2//W의 낮은 비검지도를 나타내었다. 또한 출력파형의 쵸핑주파수 및 온도 의존성에 대한 정성적인 해석으로부터 적외선 검지기의 열잡음전압 및 열시정수가 모두 상당히 크다는 것을 알 수 있었다.

Magnetic Properties of Multiferroic $BiFeO_3/BaTiO_3$ Bi-layer Thin Films

  • Yang, P.;Byun, S.H.;Kim, K.M.;Lee, Y.H.;Lee, J.Y.;Zhu, J.S.;Lee, H.Y.
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.318-319
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    • 2008

  • In this article, magnetic properties of multiferroic bi-layer $BiFeO_3$ (BFO)/$BaTiO_3$ (BTO) thin films were studied. It was found that the magnetization increased by the insertion of BTO buffer layer even though the interfacial stress was slightly relaxed, which indicated a coupling between the ferroelectric and ferromagnetic orders. Furthermore, with slightly increase of BFO film thickness, both BFO and BFO/BTO bi-layer films showed anisotropic magnetic properties with higher in-plane magnetization than the values measured out-of-plane. These are attributable to strain constraint effect at the interface.

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