• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.300-303
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• 2001

BSCCO thin films are fabricated via a co-deposition process by an ion beam sputtering with an ultra-low growth rate, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element exhibits a characteristic temperature dependence : almost a constant value of 0.49 below 730$^{\circ}C$ and decreases linearly with temperature over 730$^{\circ}C$. This temperature dependence can be elucidated from the evaporation and sublimation rates of bismuth oxide, Bi$_2$O$_3$, from the film surface. It is considered that the liquid phase of the bismuth oxide plays an important role in the Bi 2212 phase formation in the co-deposition process.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.213-216
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• 1999

BSCCO thin films are fabricated via a co-deposition process by an ion beam sputtering with an ultra-low growth rate, and sticking coefficients of the respective elements are evaluated. The sticking coefficient of Bi element exhibits a characteristics temperature dependence : almost a constant value of 0.49 below 730$^{\circ}C$ and decreases linearly with temperature over 730$^{\circ}C$. This temperature dependence can be elucidated from the evaporation and sublimation rates of bismuth oxide, Bi$_2$O$_3$ from the film surface. It is considered that the liquid phase of the bismuth oxide plays an important role in the Bi(2212) phase formation in the co-deposition process.

• 한국자기학회지
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• 제1권2호
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• pp.31-36
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• 1991

스퍼터링에 의해 형성된 비정질 Co/sub 87/Zr/sub 4/Nb/sub 9/ 박막을 TEM과 EDS로 분석하여 박막의 구조적 그리고 저성적 불균일성을 관찰하였다. 특히 기판 bias를 가한 상태에서 제조된 박막을 회전 자장 열처리했을 때는 Co-rich 지역과 (Zrnb) oxied-rich 지역의 조대한 조직으로 분리되었으며, 이러한 박 막의 자기적 특성은 'ultra-soft'한 성질을 나타내었다. Ulta-soft함 박막은 H/sub c/=0.18 Oe, H/sub k/ = 0.55 Oe, M/sub r//M/sub s/=0.75의 자기적 특성과 overdamping된 고주파특성, 그리고 외부자계에 대한 자화율 변화곡선이 가역적이고 연속적이라는 특이한 현상을 보인다. 조성적으로 불균일한 박막의 ultra-soft 한 특성은 Co-rich 입자들이 exchange coupling energy와 magnetostatic coupling energy를 최소화 하기 위해 만드는 vortex형의 자화분포로써 설명되었다. 즉 vortex 는 여러개의 co-rich 입자들로 형성 되어있는 것으로 추정되며, 수평, 수직방향으로의 반자장 계수(demagnetizing factor)가 각각 flux closure 와 flux reversal에 의해 무시되기 때문에 vortex로 부터 CoZrNb 박막의 ultra-soft 특성을 설명할 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.467-470
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• 2004

Diamond-Like Carbon (DLC) thin film is a semiconductor with high mechanical hardness, low friction coefficient, high chemical inertness, and optical transparency. DLC thin films have widespread applications as protective coatings and solid lubricant coatings in areas such as Hard Disk Drive (HDD) and Micro-Electro-Mechanical-Systems (MEMS). In this work, the wear characteristics of DLC thin films deposited on silicon substrates using a DC-magnetron sputtering system were analyzed. The wear tracks were measured with an Atomic Force Microscope (AFM). To identify the sp2 and sp3 hybridization of carbon bonds and other bonds Raman spectroscopy was used. The structural information of DLC thin films was obtained with Fourier transform infrared spectroscopy and wear tests were conducted by using a micro-pin-on-reciprocator tester. Results showed that the wear characteristics were dependent on the sputtering conditions. The wear rate could be correlated with the bonding state of the DLC thin film.

• 한국응용과학기술학회지
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• 제19권2호
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• pp.73-78
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• 2002

The polyimide(PI) Langmuir-Blodgett(LB) ultra thin films were prepared by imidizing the PAAS LB films of PMDA and benzidine system with a thermal treatment at $250^{\circ}C$ for 30min, where the PAAS LB films were formed on substrates by using LB technique. The thicknesses of one layer of PAAS and PI LB film that deposited at the surface pressure of 27mN/m were 20.9 and 4A, respectively. At low electric field, ohmic conduction($I^{\propto}$ V) was observed and the calculated electrical conductivity was about $4.23{\times}10^{-15}{\sim}9.81{\times}10^{-15}S/cm$. The dielectric constant of LB film was about 7.0.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.41.2-41.2
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• 2011

Recently, scaling down of ULSI (Ultra Large Scale Integration) circuit of CMOS (Complementary Metal Oxide Semiconductor) based electronic devices become much faster speed and smaller size than ever before. However, very narrow interconnect line width causes some drawbacks. For example, deposition of conformal and thin barrier is not easy moreover metallization process needs deposition of diffusion barrier and glue layer. Therefore, there is not enough space for copper filling process. In order to overcome these negative effects, simple process of copper metallization is required. In this research, Cu-V thin alloy film was formed by using RF magnetron sputter deposition system. Cu-V alloy film was deposited on the plane $SiO_2$/Si bi-layer substrate with smooth and uniform surface. Cu-V film thickness was about 50 nm. Cu-V layer was deposited at RT, 100, 150, 200, and $250^{\circ}C$. XRD, AFM, Hall measurement system, and XPS were used to analyze Cu-V thin film. For the barrier formation, Cu-V film was annealed at 200, 300, 400, 500, and $600^{\circ}C$ (1 hour). As a result, V-based thin interlayer between Cu-V film and $SiO_2$ dielectric layer was formed by itself with annealing. Thin interlayer was confirmed by TEM (Transmission Electron Microscope) analysis. Barrier thermal stability was tested with I-V (for measuring leakage current) and XRD analysis after 300, 400, 500, 600, and $700^{\circ}C$ (12 hour) annealing. With this research, over $500^{\circ}C$ annealed barrier has large leakage current. However V-based diffusion barrier annealed at $400^{\circ}C$ has good thermal stability. Thus, thermal stability of vanadium-based thin interlayer as diffusion barrier is good for copper interconnection.

• Transactions on Electrical and Electronic Materials
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• 제5권5호
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• pp.169-172
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• 2004

Deep sub-micron device required to get the superior ultra thin gate oxide characteristics. In this research, I will recommend a novel shallow trench isolation structure(STI) for thin gate oxide and a $N_2$O gate oxide 30 $\AA$ by NO ambient process. The local oxidation of silicon(LOCOS) isolation has been replaced by the shallow trench isolation which has less encroachment into the active device area. Also for $N_2$O gate oxide 30 $\AA$, ultra thin gate oxide 30 $\AA$ was formed by using the $N_2$O gate oxide formation method on STI structure and LOCOS structure. For the metal electrode and junction, TiSi$_2$ process was performed by RTP annealing at 850 $^{\circ}C$ for 29 sec. In the viewpoints of the physical characteristics of MOS capacitor, STI structure was confirmed by SEM. STI structure was expected to minimize the oxide loss at the channel edge. Also, STI structure is considered to decrease the threshold voltage, result in a lower Ti/TiN resistance( Ω /cont.) and higher capacitance-gate voltage(C- V) that made the STI structure more effective. In terms of the TDDB(sec) characteristics, the STI structure showed the stable value of 25 % ～ 90 % more than 55 sec. In brief, analysis of the ultra thin gate oxide 30 $\AA$ proved that STI isolation structure and salicidation process presented in this study. I could achieve improved electrical characteristics and reliability for deep submicron devices with 30 $\AA$ $N_2$O gate oxide.

• Journal of Mechanical Science and Technology
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• 제20권8호
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• pp.1292-1301
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• 2006

This article investigates numerically the carrier-phonon interactions in thin gallium arsenide (GaAs) film structures irradiated by subpicosecond laser pulses to figure out the role of several recombination processes on the energy transport during laser pulses and to examine the effects of laser fluences and pulses on non-equilibrium energy transfer characteristics in thin film structures. The self-consistent hydrodynamic equations derived from the Boltzmann transport equations are established for carriers and two different types of phonons, i.e., acoustic phonons and longitudinal optical (LO) phonons. From the results, it is found that the two-peak structure of carrier temperatures depends mainly on the pulse durations, laser fluences, and nonradiative recombination processes, two different phonons are in nonequilibrium state within such lagging times, and this lagging effect can be neglected for longer pulses. Finally, at the initial stage of laser irradiation, SRH recombination rates increases sufficiently because the abrupt increase in carrier number density no longer permits Auger recombination to be activated. For thin GaAs film structures, it is thus seen that Auger recombination is negligible even at high temperature during laser irradiation.

• 열처리공학회지
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• 제34권2호
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• pp.75-80
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• 2021

The crystal grains of polycrystalline diamond vary depending on deposition conditions and growth thickness. The diamond thin film deposited by the CVD method has a very rough growth surface. On average, the surface roughness of a diamond thin film deposited by CVD is in the range of 1-100 um. However, the high surface roughness of diamond is unsuitable for application in industrial applications, so the surface roughness must be lowered. As the surface roughness decreases, the scattering of incident light is reduced, the heat conduction is improved, the mechanical surface friction coefficient can be lowered, and the transmittance can also be improved. In addition, diamond-coated cutting tools have the advantage of enabling ultra-precise machining. In this study, the surface roughness of diamond was improved by thermal diffusion reaction between diamond carbon atoms and ferrous metals at high temperature for diamond thin films deposited by MPCVD.

• 전자공학회논문지A
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• 제31A권10호
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• pp.108-113
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• 1994

The characteristics of the oxidation prevention layers for the copper metallization were investigated. The thin films such as Cr, TiN and Al were used as the oxidation prevention layers for copper. Ultra thin aluminum films were found to prevent the oxidation of copper up to the highest oxidation annealing temperature among the barrier layers examined in this study. It was found that oxygen did not diffuse into copper through aluminum films because of the aluminum oxide layer formed on the aluminum surface and the ultra thin aluminum film could be a good oxidation barrier layer for the copper metallization.