• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.282.1-282.1
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• 2014

산소 플라즈마 전처리가 ZnO/Si 박막 및 계면에 미치는 영향과 그것이 n-ZnO/p-Si 이종접합 다이오드의 전기적 특성에 관여하는 상관관계 등을 조사하였다. ZnO 박막을 Si 기판 위에 Sputter법으로 증착하였으며, 양질의 n-ZnO/p-Si 다이오드를 제작하기 위하여 산소 플라즈마를 이용하여 Si 기판의 표면을 전처리하는 기법을 선택하였다. 산소 플라즈마에 의해 전처리된 시편의 경우, (002) ZnO 보다 (101) ZnO가 더 우세하게 성장되었으며, (101) ZnO의 완화된 c-축 배향성 때문에 수평방향으로의 박막 성장이 이루어졌고, 그로 인해 ZnO 박막의 결정립 크기가 상대적으로 증가하는 것이 관측되었다. 이처럼 (101) 방향으로 성장된 ZnO 박막의 경우, 산소결공 등의 자생결함 밀도가 상대적으로 높아져 결국 캐리어 농도의 증가를 야기시켰다. 이러한 산소 플라즈마 전처리 효과는 n-ZnO/p-Si 이종접합 다이오드의 전도 특성과 밀접한 관련이 있으며, 특히 다이오드의 전도 특성을 현저히 개선시키는 것으로 관측되었다.

• Journal of the Korean Magnetics Society
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• v.10 no.6
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• pp.274-279
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• 2000

The microstructure and thermal properties of the Mn-IriNi-Fe exchange biased multi-layers with various buffer layers and stacking structures have been investigated. The H$_{e{\chi}}$ and the T$_{b}$ depend on the Mn-Ir grain size at the interface between the Mn-Ir layer and the Ni-Fe layer, The (111) preferred orientation of Mn-Ir/Ni-Fe on the Ta buffer layer may promote the values of J$_{k}$ and H$_{e{\chi}}$. The samples which produce the Hex have the epitaxial relationship at the interface between the Mn-Ir layer and the Ni-Fe layer due to the generation of misfit dislocation.

• Proceedings of the KAIS Fall Conference
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• 2006.11a
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• pp.162-166
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• 2006

기존의 Ni PPF를 대신하여 새롭게 Cu-Sn 합금을 barrier층으로 적용한 PPF를 제조하여, 그 제반 특성들을 조사하였다. Cu-Sn 합금도금층은 기존의 Ni PPF와 마찬가지로 반도체 substrate로서 지녀야 할 열적 안정성을 충분히 확보할 수 있음을 알 수 있었다. 또한 기지층 및 보호층과의 계면간 밀착성이 Ni PPF보다 더 우수했으며, 미세한 결정립들이 균일하게 분포한 도금층 구조를 나타내어, 이들이 Ni PPF보다 구조적으로 더욱 안정할 것임을 예상할 수 있었다. 한편 강자성 거동을 보이는 Ni PPF와는 달리 Cu-Sn PPF는 완벽한 상자성 특성을 보여, 점차 고집적, 고밀도화 되어가는 반도체 패키지의 동작중 발생할 발열 및 신호간섭의 위험이 원천적으로 제거될 수 있음을 보였으며, solderability, bondability 등의 field 특성 또한 Ni PPF와 거의 비슷함을 알 수 있었다.

• Electrical & Electronic Materials
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• v.8 no.6
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• pp.737-743
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• 1995

Two step RTD(Rapid Thermal Diffussion) of P into silicon wafer using tungsten halogen lamp was used to fabricated very shallow n$^{+}$p junction. 1st RTD was performed in the temperature range of 800.deg. C for 60 see and the heating rate was in the 50.deg. C/sec. Phosphrous solid source was transfered on the silicon surface. 2nd RTD process was performed in the temperature range 1050.deg. C, 10sec. Using 2 step RTD we can obtain a shallow junction 0.13.mu.m in depth. After RTD, the Ti-silicide process was performed by the two step RTA(Rapid Thermal Annealing) to reduced the electric resistance and to improve the n$^{+}$p junction diode. The titanium thickness was 300.angs.. The condition of lst RTA process was 600.deg. C of 30sec and that of 2nd RTA process was varied in the range 700.deg. C, 750.deg. C, 800.deg. C for 10sec-60sec. After 2 step RTA, sheet resistance was 46.ohm../[]. Ti-silicide n+p junction diode was fabricated and I-V characteristics were measured.red.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.3 s.36
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• pp.253-258
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• 2005

Characteristics of electroplated Ni films such as grain size, resistivity, solder wetting angle, and growth rate of intermetallic compound were evaluated as a function of electroplating current density. With increasing the electroplating current density from $5\;mA/cm^2 $ to $40\;mA/cm^2 $, the nodule size on the Ni film surface decreased, grain refinement occurred, and resistivity increased from $7.37\mu\Omega-cm$ to $9.13\mu\Omega-cm$. Compared with Ni film processed at $40\;mA/cm^2 $, Ni films electroplated at $5\;mA/cm^2 $ and $10\;mA/cm^2 $ exhibited low resistivity, dense microstructure, and slow growth rate of intermetallic compound. Ni films electroplated at $5\;mA/cm^2 $ and $10\;mA/cm^2 $ are more suitable for Ni UBM application than that fabricated at $40\;mA/cm^2 $.

• Journal of the Korean Magnetics Society
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• v.24 no.5
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• pp.140-145
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• 2014

We analyzed the MnIr thickness dependence of torque signals measured in exchange coupled CoFe/MnIr ($t_{AF}$) bilayers. The measured torque signals were compared with calculated ones by Stoner-Wohlfarth model. The exchange coupling anisotropy $J_c$ was considered for the model calculation between ferromagnetic (F) and antiferromagnetic (AF) layers with uniaxial anisotropy constant of $K_F$ and $K_{AF}$, respectively. The rotational losses were appeared in the range of $0.5t_c$ < $t_{AF}$ < $t_c$ ($=J_c/K_{AF}$) by the unpinned AF layer. While, the unidirectional anisotropy ($J_k$) was caused by the pinned AF layer at $t_{AF}$ > $t_c$. The critical thickness of MnIr layer was $t_c$ = 3.4 nm in CoFe/MnIr bilayers. The rotational losses behavior as shown in $t_{AF}$ = 3 nm sample were explained by the random orientation of the easy axis of AF grains. The unidirectional anisotropy obtained from torque signal of $t_{AF}$ = 10 nm sample was $J_k=0.63J_c$. Thus, the unidirectional anisotropy can be enhanced up to $J_k=J_c$ by aligning the AF easy axis.

• Korean Journal of Materials Research
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• v.7 no.8
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• pp.654-659
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• 1997

HMDS[Si$_{2}$(CH$_{3}$)$_{6}$]단일 선구체를 이용하여 화학증착 방법으로 성장된 3C-SiC/Si(001) 이종접합박막의 특성을 XRD, 라만 스펙트럼 및 투과전자현미경(TEM)등을 이용하여 조사하였으며 시판되고 있는 상용 3C-SiC/Si 시편을 같은 방법으로 분석하여 특성을 비교검토하였다. $C_{3}$H$_{8}$-SiH$_{4}$-H$_{2}$혼합가스를 선구체로 이용하여 5$\mu\textrm{m}$두께로 성장된 상용 3C-SiC/Si 이종접합박막 시료의 XRD스펙트럼에서는 강한 3C-SiC(002)피크 만이 관찰되었으며, 라만 스펙트럼의 LO피크는 970nm$^{-1}$ 정도에서 강하게 나타났다. TEM 관찰 결과 다수의 전위, 쌍정, 적층결함 및 APB와 같은 결정결함들이 3C-SiC/Si 계면 근처에 집중적으로 분포되어 있었으며 성장된 박막은 단결정임을 확인할 수 있었다. 선구체로 HMDS를 사용하여 0.3$\mu\textrm{m}$ 및 2$\mu\textrm{m}$ 두께로 성장시킨 3C-SiC/Si 박막 시료의 XRD 스펙트럼은 다소 완만한 3C-SiC(002) 피크와 함께 3C-SiC(111)피크가 관찰되었으며, TEM으로 확인한 결과 소경각 결정립들이 약 5˚-10˚ 정도 방위차를 가지고 성장하여 기둥구조(columnar structure)를 이루고 있기 때문임을 알 수 있었다. 라만 스펙트럼 분석 결과 박막의 LO 피크가 967-969nm$^{-1}$정도로 다소 낮은 wavenumber쪽으로 이동되어 박막 내에 상당한 응력이 존재함을 확인할 수 있었다. 이와 같은 HMDS 3C-SiC박막의 특성은 성장 온도가 낮고 박막 성장용 가스로 사용한 HMDS 선구체에서 탄소가 과잉으로 공급되기 때문으로 제안되었다.다.

• Korean Journal of Materials Research
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• v.1 no.4
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• pp.177-183
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• 1991

Change of the properties of selective CVD-W by $SiH_4$ reduction with the variation of deposition time and pressure has been investigated. The lime required for covering the who)to Si substrate by tungsten at $300^{\circ}C$ under the pressure of 100mtorr is approximately 30 seconds. The film thickness tends to increase linearly in the early stage of deposition process and parabolically later, sheer resistance of the film tends to decrease rapidly initially, and slowly later with deposition time. Tungsten grain size does not change much, but grain boundary becomes hazy in the pressure range of 50-300mtorr. Also no ${\beta}-W$ but only ${\alpha}-W$ was found in this pressure range. The deposition rate and electrical resistivity of tungsten tend to increase wish increasing pressure. The results of AES analysis show that pressure does not much affect Si/W ratio of the tungsten film and silicidation at the W/Si interface.

• Journal of Sensor Science and Technology
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• v.5 no.5
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• pp.69-77
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• 1996

In this paper, we fabricated the micro hotplate which consisted of a thin film heater(Pt/Cr bilayers) sandwiched with the thermal oxide and E-beam evaporated oxide. And we studied the electrical and the structural properties of Pt/Cr bilayers due to annealing temperature. When we compared the temperature measured from type k thermocouples with the temperature acquired from I.R. thermo-vision system according to the variations of emissivity, the emissivity of I-beam evaporated oxide was 0.5. The sheet resistance of Pt/Cr bilayers didn't depend on the Cr layer thickness, and it was considered as the existence of CrO between the Pt and the Cr layer. When the annealing temperature was increased from $500^{\circ}C$ to $700^{\circ}C$, the out-diffusions of Cr were increased(which was confirmed by AES depth profile) and the grain size of Pt(220) phase was enlarged also(analyzed by XRD and SEM photographs). From the results of XRD analysis and AES depth profile, the Pt/Cr bilayers annealed at $500^{\circ}C$ were more stable than any other cases in structural properties.

• Journal of the Korean Magnetics Society
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• v.11 no.2
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• pp.45-49
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• 2001

Effects of multilayer structure and annealing condition on the soft magnetic properties of sputtered Fe/CoNbZr multilayers were investigated. We observed a minimum coercivity (1.1 Oe) at 5 nm thick Fe layer and the maximum permeability (2300) at 15 nm Fe layer and high saturation magnetization in the as-deposited state. As a result of increase of Fe grain size, coercivity increases with increasing Fe layer thickness. Degradation of ${\mu}$ at the thin Fe layer region may be due to the intermixed phase of high magnetostriction, such as CoFe. Optimum annealing condition was obtained through annealing at 300 $^{\circ}C$ for 40 min (${\mu}$=2500, H$\sub$c/=0.35 Oe). Enhancement of permeability was observed in the temperature range of 250∼300$^{\circ}C$. These results may closely be related with lowering the anisotropy energy by lattice deformation (0.4%) and enhanced uniaxial anisotropy.