• 한국전기전자재료학회논문지
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• 제26권5호
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• pp.335-340
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• 2013

In this study, the plasma etching of the TaN thin film with $CH_4/BCl_3/Ar$ gas chemistries was investigated. The etch rate of the TaN thin film and the etch selectivity of TaN to $SiO_2$ was studied as a function of the process parameters, including the amount of $CH_4$. X-ray photoelectron spectroscopy (XPS) and Field-emission scanning electron microscopy (FE-SEM) was used to investigate the chemical states of the surface of the TaN thin film.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.104-104
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• 2009

Critical dimensions has rapidly shrunk to increase the degree of integration and to reduce the power consumption. However, it is accompanied with several problems like direct tunneling through the gate insulator layer and the low conductivity characteristic of poly-silicon. To cover these faults, the study of new materials is urgently needed. Recently, high dielectric materials like $Al_2O_3$, $ZrO_2$ and $HfO_2$ are being studied for equivalent oxide thickness (EOT). However, poly-silicon gate is not compatible with high-k materials for gate-insulator. To integrate high-k gate dielectric materials in nano-scale devices, metal gate electrodes are expected to be used in the future. Currently, metal gate electrode materials like TiN, TaN, and WN are being widely studied for next-generation nano-scale devices. The TaN gate electrode for metal/high-k gate stack is compatible with high-k materials. According to this trend, the study about dry etching technology of the TaN film is needed. In this study, we investigated the etch mechanism of the TaN thin film in an inductively coupled plasma (ICP) system with $O_2/BCl_3/Ar$ gas chemistry. The etch rates and selectivities of TaN thin films were investigated in terms of the gas mixing ratio, the RF power, the DC-bias voltage, and the process pressure. The characteristics of the plasma were estimated using optical emission spectroscopy (OES). The surface reactions after etching were investigated using X-ray photoelectron spectroscopy (XPS) and auger electron spectroscopy (AES).

• 한국진공학회:학술대회논문집
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• 한국진공학회 1994년도 제6회 학술발표회 논문개요집
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• pp.65-67
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• 1994

• 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.

• 한국재료학회지
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• 제21권2호
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• pp.95-99
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• 2011

The microstructure and Cu diffusion barrier property of Ta-Si-N films for various Si and N compositions were studied. Ta-Si-N films of a wide range of compositions (Si: 0~30 at.%, N: 0~55 at.%) were deposited by DC magnetron reactive sputtering of Ta and Si targets. Deposition rates of Ta and Si films as a function of DC target current density for various $N_2/(Ar+N_2)$ flow rate ratios were investigated. The composition of Ta-Si-N films was examined by wavelength dispersive spectroscopy (WDS). The variation of the microstructure of Ta-Si-N films with Si and N composition was examined by X-ray diffraction (XRD). The degree of crystallinity of Ta-Si-N films decreased with increasing Si and N composition. The Cu diffusion barrier property of Ta-Si-N films with more than sixty compositions was investigated. The Cu(100 nm)/Ta-Si-N(30 nm)/Si structure was used to investigate the Cu diffusion barrier property of Ta-Si-N films. The microstructure of all Cu/Ta-Si-N/Si structures after heat treatment for 1 hour at various temperatures was examined by XRD. A contour map that shows the diffusion barrier failure temperature for Cu as a function of Si and N composition was completed. At Si compositions ranging from 0 to 15 at.%, the Cu diffusion barrier property was best when the composition ratio of Ta + Si and N was almost identical.

• 산업기술연구
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• 제19권
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• pp.101-105
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• 1999

Ultra thin $Ta_2O_5$ gate dielectrics were prepared by RTMOCVD (rapid thermal metal organic chemical vapor deposition) using Ta source $TaC_{12}H_{30}O_5N$ and $O_2$ gaseous mixtures. As a result, $Ta_2O_5$ thin films showed significantly low leakage current compared to $SiO_2$ of identical thickness, which was due to the stabilization of the interfacial layer by NO ($SiO_xN_y$) passivation layer. The conduction of leakage current in $Ta_2O_5$ thin films was described by the hopping mechanism of Poole-Frenkel (PF) type.

• 한국재료학회지
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• 제7권12호
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• pp.1052-1057
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• 1997

현재 전기, 전자, 우주, 자동차, 무기 등의 여러 분야에서 응용되고 있는 TaNx 다층박막저항체의 특성을 개선하기 위하여 magnetron sputtering법으로 TaNx박막을 제조한 후, 온도와 질소분압에 따른 전기저항 및 TCR특성 변화를 조사하였고, 미세조직이 이들 전기적 성질에 미치는 영향을알아보기 위해 상분석과 morphology를 관찰하였다. 그 결과, TaNx을 코팅한 박막의 전기저항은 $N_{2}$Ar이 0.4 이상에서, 금속전도특성에서 이온전도특성으로 변화하였으며,Cr이 TCR효과를 안정시키는 역할은 하여 TaNx/A $I_{2}$ $O_{3}$보다 TaNx/Cr/A $i_{2}$ $O_{3}$박막의 TCR특성이 더 안정하게 나타났다. 또한 TaNx/A $I_{2}$ $O_{3}$박막과 TaNx/Cr/A $i_{2}$ $O_{3}$박막의 경우 모두 $N_{2}$/Ar이 0-0.4정도에서 TCR효과에 좋은 특성을 나타내었다. X-선회절 실험 결과 $N_{2}$/Ar비가 1일 경우에 T $a_{2}$ $N_{.8}$이 생성되었고, 분압이 증가함에 따라 비정질이 생성되었다. morphology가 $N_{2}$/Ar이 증가함에 따라 입자의 모양이 불연속아일랜드 형태로 변화하였으며, 이것은 질소분압에 따른 전기저항 변화와 일치하였다.다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.94-98
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• 2000

Polycrystalline SBTN ferroelectric thin films were prepared by sol-gel method with various Nb mole ratios on Pt/ $SiO_2$/Si (100) substrates. The films were annealed at different temperatures and characterized in terms of phase and microstructure. Relatively a well saturated hysteresis pattern was obtained at x =0.2 in S $r_{0.8}$B $i_{2.3}$(T $a_{1-x}$ N $b_{x}$)$_2$ $O_{9+}$$\alpha$/ thin films. At an applied voltage of 5V, the dielectric constant ($\varepsilon$$_{r}$) and dissipation factor (tan $\delta$) of typical S $r_{0.8}$B $i_{2.3}$(T $a_{1-x}$ N $b_{x}$)$_2$ $O_{9+}$$\alpha$/ thin film (x=0.2) were about 236.2 and 0.034. Measured remanent polarization (2Pr) and coercive field (Ec) were 4.28C/c $m_2$, and 38.88kv/cm respectively. No fatigue was observed up to 6$\times$10$_{10}$ switching cycles at 5V and the normalized polarization reduced by a factor of only 4%.%. 4%.%. 4%.%.%.%.%.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.32.1-32.1
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• 2011

Ultra thin tantalum nitride (TaNx) films with various thicknesses (10 nm to 40 nm) have been deposited by rf magnetron sputtering technique on glass substrates. The as deposited films were systematically characterized by several analytical techniques such as X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, atomic force microscopy, UV-Vis-NIR double beam spectrophotometer and four point probe method. From the XRD results, the as deposited films are in amorphous nature, irrespective of the film thicknesses. The films composition was changed greatly with increasing the film thickness. SEM micrographs exhibited the densely pack microstructure, and homogeneous surface covered by small size grains at lower thickness deposited films. The surface roughness of the films was linearly increases with increasing the films thickness, consequently the transmittance decreased. The absorption edge was shifted towards higher wavelength as the film thickness increases.

• Journal of Electrochemical Science and Technology
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• 제4권4호
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• pp.163-170
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• 2013

Tantalum anodic oxide film was prepared in citric acid solution of various concentrations and the prepared Ta anodic oxide film was characterized by various electrochemical techniques and X-ray photoelectron spectroscopy (XPS). The prepared Ta anodic oxide film showed typical n-type semiconducting properties and the dielectric properties were strongly dependent on the citric acid concentration. The variation of electrochemical and electronic properties was explained in terms of electrolyte anion incorporation into the anodic oxide film, which was supported by XPS measurements.