• 제목/요약/키워드: tunnel junction

검색결과 220건 처리시간 0.064초

고밀도 플라즈마 식각에 의한 CoTb과 CoZrNb 박막의 식각 특성 (Etch Characteristics of CoTb and CoZrNb Thin Films by High Density Plasma Etching)

  • 신별;박익현;정지원
    • Korean Chemical Engineering Research
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    • 제43권4호
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    • pp.531-536
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    • 2005

  • 포토리지스트 마스크로 패턴된 CoTb 및 CoZrNb 자성 박막에 대한 유도 결합 플라즈마 반응성 이온 식각이 $Cl_2/Ar$와 $C_2F_6/Ar$ 가스를 이용하여 진행되었고 식각 속도와 식각 프로파일 측면에서 조사되었다. $Cl_2$와 $C_2F_6$ 가스의 농도가 증가함에 따라서 자성 박막들의 식각 속도는 감소하였고 식각 경사는 낮아졌다. 자성 박막들의 식각 가스로서 $Cl_2/Ar$이 빠른 식각 속도와 가파른 식각 경사를 얻는데 있어서 $C_2F_6/Ar$ 보다 더 효과적이었다. Coil rf power의 증가는 플라즈마 내의 Ar 이온과 라디칼의 밀도를 증가시키고 dc bias voltage의 증가는 기판으로 스퍼터되는 Ar 이온의 에너지를 증가시키기 때문에 coil rf power와 dc bias voltage가 증가할수록 식각 속도와 식각 경사는 증가하였지만 패턴의 측면에서 재증착이 일어났다. 자성 박막들의 적층으로 형성된 magnetic tunnel junction stack에 고밀도 플라즈마 반응성 이온 식각을 적용하여, 높은 식각 경사와 재증착이 없는 깨끗한 식각 프로파일을 얻었다.

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Optimum design of RC shallow tunnels in earthquake zones using artificial bee colony and genetic algorithms

  • Ozturk, Hasan Tahsin;Turkeli, Erdem;Durmus, Ahmet
    • Computers and Concrete
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    • 제17권4호
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    • pp.435-453
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    • 2016

  • The main purpose of this study is to perform optimum cost design of cut and cover RC shallow tunnels using Artificial bee colony and genetic algorithms. For this purpose, mathematical expressions of objective function, design variables and constraints for the design of cut and cover RC shallow tunnels were determined. By using these expressions, optimum cost design of the Trabzon Kalekapisi junction underpass tunnel was carried out by using the cited algorithms. The results obtained from the algorithms were compared with the results obtained from traditional design and remarkable saving from the cost of the tunnel was achieved.

  • https://doi.org/10.12989/cac.2016.17.4.435 인용 KSCI

A New Reference Cell for 1T-1MTJ MRAM

  • Lee, S.Y.;Kim, H.J.;Lee, S.J.;Shin, H.S.
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제4권2호
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    • pp.110-116
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    • 2004

  • We propose a novel sensing scheme, which operates by sensing the difference in voltage between a memory cell and a reference cell for a magneto-resistive random access memory (MRAM). A new midpoint-reference generation circuit is adopted for the reference cell to improve the sensing margin and to guarantee correct operation of sensing circuit for wide range of tunnel magneto resistance (TMR) voltages. In this scheme, the output voltage of the reference cell becomes nearly the midpoint between the cell voltages of high and low states even if the voltage across the magnetic tunnel junction (MTJ) varies.

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Tunneling Magnetoresistance: Physics and Applications for Magnetic Random Access Memory

  • Park, Stuart in;M. Samant;D. Monsma;L. Thomas;P. Rice;R. Scheuerlein;D. Abraham;S. Brown;J. Bucchigano
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2000년도 International Symposium on Magnetics The 2000 Fall Conference
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    • pp.5-32
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    • 2000

  • MRAM, High performance MRAM using MTJS demostrated, fully integrated MTJ MRAM with CMOS circuits, write time ~2.3 nsec; read time ~3 nsec, Thermally stable up to ~350 C, Switching field distibution controlled by size & shape. Magnetic Tunnel Junction Properties, Magnetoresistance: ~50% at room temperature, enhanced by thermal treatment, Negative and Positive MR by interface modification, Spin Polarization: >55% at 0.25K, Insensitive ot FM composition, Resistance $\times$ Area product, ranging from ~20 to 10$^{9}$ $\Omega$(${\mu}{\textrm}{m}$)$^{2}$, Spin valve transistor, Tunnel injected spin polarization for "hot" electrons, Decrease of MTJMR at high bias originates from anode.

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