• Journal of the Microelectronics and Packaging Society
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• v.23 no.3
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• pp.69-75
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• 2016

This study investigated the effect of heat treatment conditions not only on the Cr surface crack propagation behaviors but also on the Ni/Cr interfacial reaction characteristics in electroless Ni/electroplated Cr double coating layers on Cu substrate. Clear band layer of Ni-Cr solid solutions were developed at Ni/Cr interface after heat treatment at $750^{\circ}C$ for 6 h. Channeling cracks formed in Cr layer after 1 step heat treatment, that is, heat treatment after Ni/Cr plating, while little channeling cracks formed after 2 step heat treatment, that is, same heat treatments after Ni and Cr plating, respectively, due to residual stress relaxation due to crystallization of Ni layer before Cr plating.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.2
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• pp.49-55
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• 2016

The effects of post-annealing and temperature/humidity conditions on the interfacial adhesion energies of atomic layer deposited RuAlO diffusion barrier layer for Cu interconnects were systematically investigated. The initial interfacial adhesion energy measured by four-point bending test was $7.60J/m^2$. The interfacial adhesion energy decreased to $5.65J/m^2$ after 500 hrs at $85^{\circ}C$/85% T/H condition, while it increased to $24.05J/m^2$ after annealing at $200^{\circ}C$ for 500 hrs. The X-ray photoemission spectroscopy (XPS) analysis showed that delaminated interface was RuAlO/$SiO_2$ for as-bonded and T/H conditions, while it was Cu/RuAlO for post-annealing condition. XPS O1s peak separation results revealed that the effective generation of strong Al-O-Si bonds between $AlO_x$ and $SiO_2$ interface at optimum post-annealing conditions is responsible for enhanced interfacial adhesion energies between RuAlO/$SiO_2$ interface, which would lead to good electrical and mechanical reliabilities of atomic layer deposited RuAlO diffusion barrier for advanced Cu interconnects.

• Korean Journal of Crystallography
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• v.13 no.3_4
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• pp.165-171
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• 2002

Single phase $Pb(Fe_{1/2}Ta_{1/2})O_3$, ceramics were successfully synthesized from the powders prepared by solid state reaction (sintering temperature: $1100^{\circ}C$, density: $9.3g/cm^3$, average grain size: $5.1{\pm}1.2mm$, space group: Pm3m). Their dielectric properties measured at $-150{\sim}50^{\circ}C$ showed the maximum relative dielectric constant of 31000 at $-41^{\circ}C$. 1 kHz, and typical relaxor ferroelectrics characteristics such as diffuse phase transition and dielectric relaxation phenomena. However, the diffuseness of phase transition decreased and the dielectric properties became more normal ferroelectrics as the time of annealing at $1000^{\circ}C$ increased. By using Raman spectroscopy, it was revealed that the $Fe^{3+}$ and $Ta^{5+}$ ions in the as-sintered $Pb(Fe_{1/2}Ta_{1/2})O_3$, are stoichiometrically 1 : 1 ordered within the short-range that can not be probed even by transmission electron microscopy, and this stoichiometric 1 : 1 ordering is enhanced by the annealing. The relaxor ferroelectric characteristics in the as-sintered $Pb(Fe_{1/2}Ta_{1/2})O_3$, could be correlated with the stoichiometric 1 : 1 short-range ordering of B-site cations, and the decrease of relaxor ferroelectric characteristics in the annealed $Pb(Fe_{1/2}Ta_{1/2})O_3$ could be correlated with the enhanced stoichiometric 1 : 1 short-range ordering of B-site cations.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.211-214
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• 2004

In the present study, the effect of SIDT (Strain Induced Dynamic Transformation) on the microstructure of medium carbon steels was investigated to develop spheroidized annealing-free steel wire rods. When $0.45\%C$ steels were hot-deformed under the conditions of heavy reduction at low temperatures, a microstructure quite different from conventional ferrite-pearlite structure was obtained. It was considered that this ferrite-cementite microstructure was obtained because very small retained austenite grains existing between fine SIDT ferrites prefer to transform to cementite and ferrite instead of pearlite during cooling. Through the present study, $0.45\%C$ steels containing ferrite-cementite (FC) structure instead of ferrite-pearlite structure was obtained in as-rolled state by introducing SIDT. The specimen containing the FC structure was much softer than that containing conventional ferrite-pearlite structure. Therefore, it is concluded that deforming medium carbon steels under the conditions of SIDT is a very powerful method to obtain soft steel wire rods which could be cold-forged without softening heat-treatment

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.308-308
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• 2012

현재 결정질 태양전지 제작에 있어 공정 단가 및 재료비 절감을 위해 실리콘 웨이퍼의 두께가 점점 얇아지는 추세이며, 이에 따른 장파장 영역 흡수 손실을 감소시키기 위한 방안으로 후면 패시베이션에 관한 연구가 활발히 진행되고 있다. 후면 패시베이션층으로는 SiO2, SiNx, a-Si:H, SiOxNy 등의 물질이 사용되고 있으며, 본 연구에서는 SiO2/SiNx/SiO2 (ONO)의 삼중막 구조를 패시베이션층으로 하여 SiNx 단일막 구조와의 열처리 온도에 따른 소수캐리어 수명(${\tau}eff$), 후면 재결합속도(Seff), 확산거리(LD) 등의 파라미터 변화를 비교하였다. 증착 직후와 $350^{\circ}C$에서의 Forming Gas Annealing (FGA), 그리고 $800^{\circ}C$의 고온에서의 fast firing 후의 각각의 파라미터 변화를 관찰하였다. 증착 직후 SiNx 단일막과 ONO 삼중막의 소수캐리어 수명은 각각 $108{\mu}s$와 $145{\mu}s$를 보였다. 후면 재결합속도는 65 cm/s와 44 cm/s를 보였으며, 확산거리는 각각 $560{\mu}m$와 $640{\mu}m$를 나타내었다. FGA와 firing 열처리 후 세 파마미터는 모두 향상된 값을 보였으며 최종 firing 처리 후 단일막과 삼중막의 소수캐리어 수명은 각각 $196{\mu}s$와 $212{\mu}s$를 보였다. 또한 후면 재결합속도는 28 cm/s와 24 cm/s를 보였으며, 확산거리는 각각 $750{\mu}m$와 $780{\mu}m$를 보여 ONO 삼중막 구조의 경우에서 보다 우수한 특성을 보였다. 본 실험을 통해 SiNx 단일막보다 ONO 패시베이션 구조에서의 열적안정성이 우수함을 확인하였으며, 또한 ONO 패시베이션 구조는 열적 안정성뿐 아니라 n-type 도핑을 위한 Back To Back (BTB) 도핑 공정 시 후면으로 의 도펀트 침투를 막는 차단 층으로서의 역할도 기대할 수 있다.

• Korean Journal of Plant Resources
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• v.23 no.2
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• pp.123-130
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• 2010

Present studies were conducted to investigate the effects of autoclaving on antioxidant activities of Achillea alpina and Solodago virgurea. At early April, young leaves of 2 species were collected, subjected to autoclaving ($121^{\circ}C$, 1.2 atmospheric pressure, 15 minutes), freezed-dried, grinded, and extracted with 80% ethanol. The same process was repeated with unautoclaved control. Total polyphenol and flavonoid contents, scavenging activities on DPPH and ABTS radicals and ferrous ion chelating effects were analyzed. Extraction yield of autoclaved S. virgurea was 39.55% and A. alpina 28.15%. In both species, autoclaving significantly reduced scavenging activities on DPPH and ABTS radicals. On the contrary, ferrous ion chelating effects increased after autoclaving, especially in young leaves of A. alpina. Autoclaving resulted in decrease of polyphenol and flavonoid contents, especially in the A. alpina. The present experiments demonstrated that autoclaving had negative effects on antioxidant activities of A. alpina and S. virgurea, except in ferrous ion chelating effects. Young leaves of former species were unstable to heat treatment, resulting in big lose of antioxidant activity.

• Journal of Korean Society of Steel Construction
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• v.29 no.1
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• pp.37-48
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• 2017

In this research, 9 SAW welding specimens with 1 hour post-heat treatment (PH1) and 2 hours (PH2) were experimented to confirm the weldability and the joint performance of 60mm thickness HSA800 steel. SAW tests with PH1 & PH2, including weld impact test, bend test, hardness test, macroscopic test, and microscopic test, had a good test results. However, from the chemical composition test results, P composition was not satisfied with Korean Industrial Standards(KS). According to the weld-zone tensile tests, 2 hours post-heat SAW is recommended because the mechanical characteristics of SAW PH2 were better than those of SAW PH1.

• Applied Microscopy
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• v.30 no.3
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• pp.249-254
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• 2000

We investigated the microstructure, electrical property, and magnetic property of Co/Al multilayer after annealing treatment. CoAl was formed during depositing Co/Al multilayer due to the interfacial reaction. After annealing treatment, $Co_2Si$ was formed at the Co/Si interface. The sheet resistance of Co 2 nm/Al 2 nm multilayer have the lowest value and the Rs of multilayer decreased with the increase of annealing temperature due to the formation of $Co_2Si$ phase. The Ms of 2 nm Co/2 nm Al multilayer have the lowest value and the Ms of multilayer increased with the increase of film thickness.

• Journal of the Korean Magnetics Society
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• v.8 no.4
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• pp.185-191
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• 1998

Magnetic domain structure and static magnetic properties were investigated in the ultra thin 3%Si-Fe strip wound cores when the strips were wound and annealed to relief the stress. The elastic and plastic deformation due to the radius of curvature was also investigated for the cores. At the as-wound state, the maze pattern domain structure was generated on the concave surface of the core and 180$^{\circ}$ domain wall was recovered by annealing 600 $^{\circ}C$$\times$30 min. After annealed by 900 $^{\circ}C$$\times$30 min, Hc of strip-wound cores was not reached to the $H_c$ of the strip even at the cores of elastic deformation region. It is necessary to relief the local stress remained in the core when the cores were manufactured for the application of ultra-thin 3%Si-Fe strip.

• Korean Journal of Materials Research
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• v.6 no.8
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• pp.852-857
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• 1996

Crystallization characteristics of titanium oxide thin film during post-annealing of reactive sputter deposition were studied. Amorphous phases of as-deposited films were crystallized into rutile after annealing at $900^{\circ}C$ and anatase at $500^{\circ}C$, respectively when $O_2$ concentration during sputtering was more than 15%. However, rutile was the only phase obtainable after annealing if %$O_2$ was less than 10%. For these films, Magneli phase($Ti_nO_{2n-1}$) were crystallized below $500^{\circ}C$ at first place due to slow oxidation of nonstoichiometric films but $500^{\circ}{\sim}600^{\circ}C$ anatase with nonstoichiometry was crystallized for a short period. It was, therefore, concluded that crystal growth can proceed without phase transition if stoichiometric phase is formed at the first stage of crystallization, and that rutile, the most stable phase, was resulted from any oxygen deficient nonstoichiometric films.