• 한국재료학회:학술대회논문집
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• 한국재료학회 1997년도 한국재료학회 추계학술발표회
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• pp.145-145
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• 1997

• 한국재료학회:학술대회논문집
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• 한국재료학회 1999년도 춘계학술발표강연 및 눈문개요집
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• pp.114-114
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• 1999

• 반도체디스플레이기술학회지
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• 제4권2호
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• pp.39-43
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• 2005

In the study, in order to deposit TaN thin film for diffusion barrier and bottom electrode we made the Plasma Assisted ALD equipment and confirmed the electrical characteristics of TaN thin films grown PAALD method. Plasma Assisted ALD equipment depositing TaN thin film using PEMAT(pentakis(ethylmethlyamino) tantalum) precursor and NH3 reaction gas is shown that TaN thin film deposited high density and amorphous phase with XRD measurement. The degree of diffusion and reaction taking place in Cu/TaN (deposited using 150W PAALD)/$SiO_{2}$/Si systems with increasing annealing temperature was estimated for MOS capacitor property and the $SiO_{2}$, (600${\AA}$)/Si system surface analysis by C-V measurement and secondary ion material spectrometer (SIMS) after Cu/TaN/$SiO_{2}$ (400 ${\AA}$) layer etching. TaN thin film deposited PAALD method diffusion barrier have a good diffusion barrier property up to 500$^{\circ}C$.

• 한국결정성장학회지
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• 제18권4호
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• pp.165-168
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• 2008

동시스퍼터법을 이용하여 Ta이 도핑된 $TiO_2$ 박막을 석영 및 ITO 기판위에 제작하였다. Ta의 도핑량은 동시스퍼터법에 의하여 조절되는 Ta 금속선 길이에 의하여 제어 되었다. Ta이 도핑된 $TiO_2$ 박막은 rutile상에서 anatase상으로 구조변화를 유발 시키며 고용체를 형성했다. Ta의 도핑량이 증가함에 따라 rutile상 보다는 anatase상이 많은 것으로 나타났다. XPS 분석에 따르면 도핑된 Ta은 금속이 아닌 $Ta_2O_5$의 산화물을 형성하는 것으로 나타났다. Ta이 도핑된 $TiO_2$ 전극에서는 자외선(UV) 영역을 포함하여 가시광(VIS) 영역의 빛의 조사에 광전류응답 특성을 발현하였다. 가시광선 영역에서 발현된 광전류 응답 특성은 Ta 도핑에 의하여 $TiO_2$ 밴드갭내에 불순물 준위의 형성에 기인한 것으로 사료된다.

• 한국재료학회지
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• 제12권10호
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• pp.814-819
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• 2002

TiN and TaN films as electrode materials of reactive sputtered $Ta_2$$O_{5}$ were prepared by sputtering to compare their thermal stabilities with $Ta_2$$O_{5}$ The microstructural change of $Ta_2$$O_{5}$ films with annealing was also investigated. As- deposited $Ta_2$$O_{5}$ film on $SiO_2$ was amorphous and annealing of 80$0^{\circ}C$ for 30 min made it transform to $\beta$-Ta$_2$O$_{5}$ crystalline which contains amorphous particles with the size of a few nm. Crystallization temperature of Ta$_2$Ta_2$$O_{5}$ on TaN is higher than that on TiN electrode. The interface between TaN and Ta$_2$O$_{5}$ maintained stably even after vacuum annealing up to $800^{\circ}C$ for 1 hr, but TiN interacted with $Ta_2$$_O{5}$ and so interdiffusion between TiN and $Ta_2$$O_{5}$ occurred by vacuum annealing of 80$0^{\circ}C$ for 1 hr. It indicates that TaN is thermally more stable with $Ta_2$$O_{5}$ than TiN.N.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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• pp.165-168
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• 2000

We fabricated ramp-edge Josephson junctions with barriers formed by interface treatments instead of epitaxially grown barrier layers. A low-dielectric Sr$_2$AlTaO$_6$(SAT) layer was used as an ion-milling mask as well as an insulating layer for the ramp-edge junctions. An ion-milled YBa$_2$Cu$_3$O$_{7-x}$ (YBCO)-edge surface was not exposed to solvent through all fabrication procedures. The barriers were produced by structural modification at the edge of the YBCO base electrode using high energy ion-beam treatment prior to deposition of the YBCO counter electrode. We investigated the effects of high energy ion-beam treatment, annealing, and counter electrode deposition temperature on the characteristics of the interface-controlled Josephson junctions. The junction parameters such as T$_c$, I$_c$c, R$_n$ were measured and discussed in relation to the barrier layer depending on the process parameters.

• 한국물환경학회지
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• 제33권1호
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• pp.34-39
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• 2017

Under a corrosive environment, electrodes that are applied in the water-treatment system need not only very high electrochemical activity for fast reactions, but also high durability for cost saving. Therefore, the fabrication condition of iridium electrodes was examined to produce a more durable iridium electrode in this study. Tantalum was selected as a binder to enhance the durability of the iridium electrode. Investigation of the weight ratio between the catalyst and the binder to improve electrochemical activity was performed. Also, to compare the effect of the different coating amounts of the catalyst, the results of CV (Cyclic Voltammetry) and EIS (Electrochemical Impedance Spectroscopy) were discussed. Furthermore, an ALT(Accelerated Lifetime Test) was designed and applied to the electrodes to determine the conditions for highly durable electrode fabrication.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.28.2-28.2
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• 2011

Resistance random access memory (ReRAM) is a promising candidate for next-generation nonvolatile memory because of its advantageous qualities such as simple structure, superior scalability, fast switching speed, low-power operation, and nondestructive readout. We investigated the resistive switching behavior of tantalum oxide that has been widely used in dynamic random access memories (DRAM) in the present semiconductor industry. As a result, it possesses full compatibility with the entrenched complementary metal-oxide-semiconductor processes. According to previous studies, TiN is a good oxygen reservoir. The TiN top electrode possesses the specific properties to control and modulate oxygen ion reproductively, which results in excellent resistive switching characteristics. This study presents fully room temperature fabricated the TiN/$TaO_x$/Pt devices and their electrical properties for nonvolatile memory application. In addition, we investigated the TiN electrode dependence of the electrical properties in $TaO_x$ memory devices. The devices exhibited a low operation voltage of 0.6 V as well as good endurance up to $10^5$ cycles. Moreover, the benefits of high devise yield multilevel storage possibility make them promising in the next generation nonvolatile memory applications.

• 한국전기전자재료학회논문지
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• 제11권3호
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• pp.229-236
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• 1998

Ferroelectric $Sr_xBi_yTa_2O_{9+\alpha}$/(0.7$\leqSr\leq1.0,\; 2.0\leqBi\leq2.6)$ solutions were prepared by MOD (Metalorganic Deposition) process. These solutions were made into thin films with thickness ranging from 1500~2000${\AA}$ by spin coating. The phase transformation of the SBT thin films by variation of annealing temperature and annealing time were observed using high temperature XRD and SEM. The crystallization and grain growth of SBT thin film were accomplished at $800^{\circ}C$ for 30 minutes after deposition of Pt top electrode by sputtering to prevent electrical breakdown. Ferroelectric properties of the SBT thin films were measured in the range of $\pm$3V\; and\; \pm5V$. The specimen with composition ratio of Sr/Bi/Ta (0.8/2.4/2.0) has the excellent ferroelectric properties ; $2P_r = 10.5,\; 13.2\muC/cm^2 \;at\; \pm3V\; and\; \pm5V$ respectively. Observing the post annealed Pt/SBT/Pt interface by SEM, it was found that Pt electrode sputtered on to the SBT thin film penetrated into the hollow on the SBT thin film, thus decreasing the effective insulation thickness. The effective insulation thickness recovered by post annealing, and this was confirmed by leakage current density measurement.

• Bulletin of the Korean Chemical Society
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• 제16권9호
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• pp.819-823
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• 1995

Thin films of two kinds of Prussian Blue (PB)-modified, using iron(Ⅲ) complex instead of conventional FeCl3, were prepared on a gold substrate and these films were able to be electrochemically reduced in potassium nitrate solution. In case of PB-modified films prepared from Fe(Ⅲ)-ethylenediamine-N,N'-diacetic acid (FeEN3+)/K3Fe(CN)6 solution, the mid-peak potential was 0.156 V in 0.1 M KNO3 and it was found that potassium ion migrates into or out of the film during the electrolysis. These films were shown to be electrochromic. These films exhibited smaller peak separation than those formed from Fe(Ⅲ)-tartaric acid (FeTA3+)/K3Fe(CN)6 system. The diffusion coefficient of Fe(CN)63-/4- redox couple, evaluated using the fabricated Au rotating disc electrode(rde) previously reported, was in good agreement with the existing data. Two experimental procedures, including the voltammetry at relatively low scan rates and the rde study, have been used in order to characterize the electrode kinetics. The electrode kinetics of some redox couples (FeEN2+-FeEN3+ and FeTA2+-FeTA3+) on both PB-modified thin films and bare Au electrode were studied using a Au rde. In all cases the rate constants of electron transfer obtained with the PB-modified film electrodes were only slightly less than those obtained for the same reaction on bare Au disc electrodes. The conductivities, as determined from the slopes of the i-V curves for a ca. 1 mm sample for dried PB-modified potassium-rich and deficient bulk samples pressed between graphite electrodes, were 6.21 × 10-7 and 2.03 × 10-7(Ω·cm)-1, respectively.