• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.3
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• pp.458-464
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• 2017

A magnetic tunnel junction (MTJ) based ternary content addressable memory (TCAM) is proposed which provides non-volatility. A unit cell of the TCAM has two MTJ's and 4.875 transistors, which allows the realization of TCAM in a small area. The equivalent resistance of parallel connected multiple unit cells is compared with the equivalent resistance of parallel connected multiple reference resistance, which provides the averaging effect of the variations of device characteristics. This averaging effect renders the proposed TCAM to be variation-tolerant. Using 65-nm CMOS model parameters, the operation of the proposed TCAM has been evaluated including the Monte-Carlo simulated variations of the device characteristics, the supply voltage variation, and the temperature variation. With the tunneling magnetoresistance ratio (TMR) of 1.5 and all the variations being included, the error probability of the search operation is found to be smaller than 0.033-%.

• Journal of Magnetics
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• v.6 no.4
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• pp.126-128
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• 2001

The effect of rapid thermal anneal (RTA) has been investigated on the properties of an FeMn exchange-biased magnetic tunnel junction (MTJ) using magnetoresistance and I-V measurements and transmission electron microscopy (TEM). The tunneling magnetoresistance (TMR) in an as-grown MTJ is found to be ∼27%, while the TMR in MTJs annealed by RTA increases with annealing temperature up to 300$\^{C}$, reaching ∼46%. A TEM image reveals a structural change in the interface of A1$_2$O$_3$layer for the MTJ annealed by RTA at 300$\^{C}$. The oxide barrier parameters are found to vary abruptly with annealing time within a few ten seconds. Our results demonstrate that the present RTA enhances the magnetoresistive properties of MTJs.

• Journal of the Korean Magnetics Society
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• v.16 no.6
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• pp.271-275
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• 2006

We investigated the magnetoresistance of perpendicularly magnetized magnetic tunnel junction composed of Co/Pd multilayers. The magnetoresistance was maximized with Co electrodes of about 5 nm thickness, which evidenced the important role of the interface in tunneling process. Both the change in perpendicular magnetic anisotropy and improvement of junction resistance were observed with changing Co sublayers, while the spin scattering became dominant with increasing Pd sublayers.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.853-856
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• 2005

Inductively coupled plasma reactive ion etching of magnetic tunnel junction (MTJ) stack, which is one of the key elements in magnetic random access memory, was studied. The MTJ stacks were patterned in nanometer size by electron(e)-beam lithography, and TiN thin films were employed as a hard mask. The etch process of TiN hard mask was examined using Ar, $Cl_2/Ar$, and $SF_6/Ar$. The TiN hard mask patterned by e-beam lithography was first etched and then the etching of MTJ stack was performed. The MTJ stacks were etched using Ar, $Cl_2/Ar$, and $BCl_3/Ar$ gases by varying gas concentration and pressure.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.05a
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• pp.20-21
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• 2000

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.14-14
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• 2014

STT-MRAM의 구성물질인 magnetic tunnel junction의 효과적인 식각을 위하여 다양한 가스 조합을 연구하였다. 그 결과 $CH_4/N_2O$ gas 조합보다는 $CH_3OH$ gas 가 보다 향상된 식각 특성을 나타내었고 pulse duty ratio 변화와 기판온도 변화가 식각특성 향상에 영향을 주었음을 알 수 있었다.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.144-145
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• 2002

Al$_2$O$_3$층을 터널 장벽으로 사용하는 Magnetic Tunnel Junction(MTJ)시료의 특성에 가장 크게 작용하는 요인 중에 한 가지는 양질의 Al산화막 형성에 있다. Al산화막이 터널 장벽으로 제대로 된 역할을 하기 위해서는 Al층에 인접한 자성층에 영향을 미치지 않으면서 Al층을 균일하게 산화시킬 수 있는 조건이 만족되어야 하며, 이러한 $Al_2$O$_3$층의 제작에 가장 적합한 실험적 조건은 Al층의 산화에 Low power plasma를 사용하며, 산화 Chamber내부를 되도록 높은 분압의 산소 분위기로 유지시켜서 조금씩 장시간 동안 Al을 산화시키는 것이다. (중략)

• Proceedings of the Korean Magnestics Society Conference
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• 2001.04a
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• pp.34-35
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• 2001

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.6
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• pp.556-561
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• 2013

Interest in spin-torque oscillators (STOs) has been increasing due to their potential use in communication devices. In particular the magnetic tunnel junction-based STO (MTJ-STO) with high perpendicular anisotropy is gaining attention since it can generate high output power. In this paper, a circuit-level model for an in-plane magnetized MTJ-STO with partial perpendicular anisotropy is proposed. The model includes the perpendicular torque and the shift field for more accurate modeling. The bias voltage dependence of perpendicular torque is represented as quadratic. The model is written in Verilog-A, and simulated using HSPICE simulator with a current-mirror circuit and a multi-stage wideband amplifier. The simulation results show the proposed model can accurately replicate the experimental data such that the power increases and the frequency decreases as the value of the perpendicular anisotropy gets close to the value of the demagnetizing field.

• Proceedings of the Korean Magnestics Society Conference
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• 2005.06a
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• pp.90-90
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• 2005