A Solid-State Thin-Film Electrolyte, Lithium Silicon Oxynitride, Deposited by using RF Sputtering for Thin-Film Batteries

Dan Na,Byeongjun Lee,Baeksang Yoon,Inseok Seo 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.76 No.9

In this study, a new lithium-silicon-oxynitride (LiSiON) solid-state thin-film electrolyte was investigated for the first time. The LiSiON thin-film electrolyte was deposited by using the RF sputtering technique. In order to compare the LiSiON thin-film electrolyte to lithium phosphorous oxynitride (LiPON), a conventional thin-film electrolyte, were deposited LiPON thin-film electrolytes by using RF sputtering. Surface morphologies and cross-sectional views of the thin-film electrolytes were characterized by using field emission scanning electron microscopy (FE-SEM). The thin-films showed smooth surfaces without any cracks and pinholes. The smooth surfaces are thought to decrease the interfacial resistance between the electrolyte and the electrodes. In addition, surface morphologies were characterized by using atomic force microscopy (AFM). The sputtering rates were calculated using the thicknesses of the thin-films, as obtained from cross-sectional views. The structural properties of the thin-films were characterized using X-ray diffraction (XRD). All thin-films showed amorphous properties compared to the target material which is a crystalline material. The ionic conductivity of the LiSiON thin-film was 2.47 × 10-6 (S/cm), which is slightly higher than that of a common thin-film electrolyte LiPON.

Possibility of BaTiO3 thin films prepared on Cu substrates for embedded decoupling capacitors by an aerosol deposition method

Jong-Min OH,Song-Min NAM 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.5

BaTiO3 thin films were fabricated on Cu substrates at room temperature employing an aerosol deposition method (ADM) for embedded decoupling capacitors with high capacitance densities in the thickness range of 12 to 0.2 μm. From the thickness dependence of their dielectric properties, it was confirmed that BaTiO3 thin films acted like conductors due to high leakage currents or as dielectrics in near a thickness of 1.0 μm. In this thickness range, we suggest that their high leakage current densities resulted from defects in the BaTiO3 thin films. Through SEM observation, it was determined that the high leakage current densities of BaTiO3 thin films were caused by defects such as pores, craters and weakly bonded areas due to large particles and agglomerated particles. To reconfirm the non-uniformity of the thin film due to defects, we reduced the diameter of the upper electrodes from 1.5 to 0.33 mm. As a result, the dielectric properties of BaTiO3 thin films with upper electrodes of 0.33 mm in diameter could be measured first in a thickness of 0.5 μm. The relative permittivity, loss tangent and capacitance densities were approximately 66, 0.026 and 114 nF/㎠ at 10 kHz, respectively. Therefore, the possibility of thin films for embedded decoupling capacitors with high capacitance density through an ADM process may be proposed. BaTiO3 thin films were fabricated on Cu substrates at room temperature employing an aerosol deposition method (ADM) for embedded decoupling capacitors with high capacitance densities in the thickness range of 12 to 0.2 μm. From the thickness dependence of their dielectric properties, it was confirmed that BaTiO3 thin films acted like conductors due to high leakage currents or as dielectrics in near a thickness of 1.0 μm. In this thickness range, we suggest that their high leakage current densities resulted from defects in the BaTiO3 thin films. Through SEM observation, it was determined that the high leakage current densities of BaTiO3 thin films were caused by defects such as pores, craters and weakly bonded areas due to large particles and agglomerated particles. To reconfirm the non-uniformity of the thin film due to defects, we reduced the diameter of the upper electrodes from 1.5 to 0.33 mm. As a result, the dielectric properties of BaTiO3 thin films with upper electrodes of 0.33 mm in diameter could be measured first in a thickness of 0.5 μm. The relative permittivity, loss tangent and capacitance densities were approximately 66, 0.026 and 114 nF/㎠ at 10 kHz, respectively. Therefore, the possibility of thin films for embedded decoupling capacitors with high capacitance density through an ADM process may be proposed.

Annealing Effects of ZnO Thin Films Deposited on Si (100) by Using Pulsed Laser Deposition

F. K. Shan,G. X. Liu,B. C. Shin,W. J. Lee 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.54 No.2

ZnO thin films were deposited on Si (100) substrates at different temperatures by using pulsed laser deposition technique. An X-ray diffractometer (XRD), a scanning probe microscope and a spectrometer were used to investigate the structural, morphological and luminescent properties of the thin films. We found that the thin films had a preferred (002) orientation and that the peak intensity of the (002) orientation increased with increasing growth temperature up to 400℃. However, the peak intensity decreased when the growth temperature was over 500℃. The grain size and the roughness of the thin films depended on the growth temperature. The higher the growth temperature, the rougher the surface and the bigger the grain size. The photoluminescence (PL) of the thin films deposited at temperatures lower than 500℃ showed near-band-edge (NBE) and deep-level (DL) emissions. The peak intensity of the NBE emission increased with increasing growth temperature. The annealing effects of the thin films grown at room temperature were observed and characterized. We observed that the XRD patterns and the surface morphologies of the as-deposited thin film and the post-annealed films were little different. However, the PL spectra of the thin films annealed at different temperatures were quite different. In order to find the origin of DL emission of the as-deposited thin film, we annealed the thin films in a N2 ambient. We conclude that the DL emissions of the as-deposited ZnO thin film originated from oxygen vacancies instead of zinc interstitials. ZnO thin films were deposited on Si (100) substrates at different temperatures by using pulsed laser deposition technique. An X-ray diffractometer (XRD), a scanning probe microscope and a spectrometer were used to investigate the structural, morphological and luminescent properties of the thin films. We found that the thin films had a preferred (002) orientation and that the peak intensity of the (002) orientation increased with increasing growth temperature up to 400℃. However, the peak intensity decreased when the growth temperature was over 500℃. The grain size and the roughness of the thin films depended on the growth temperature. The higher the growth temperature, the rougher the surface and the bigger the grain size. The photoluminescence (PL) of the thin films deposited at temperatures lower than 500℃ showed near-band-edge (NBE) and deep-level (DL) emissions. The peak intensity of the NBE emission increased with increasing growth temperature. The annealing effects of the thin films grown at room temperature were observed and characterized. We observed that the XRD patterns and the surface morphologies of the as-deposited thin film and the post-annealed films were little different. However, the PL spectra of the thin films annealed at different temperatures were quite different. In order to find the origin of DL emission of the as-deposited thin film, we annealed the thin films in a N2 ambient. We conclude that the DL emissions of the as-deposited ZnO thin film originated from oxygen vacancies instead of zinc interstitials.

Vacuum evaporation of CdTe thin films on Ni, Mo, Ti and TiN-deposited sapphire single-crystal substrates

Yuichi Sato,Hirotoshi Hatori,Suguru Igarashi,Manabu Arai,Kazuki Ito,Syota Kikuchi 한국물리학회 2010 Current Applied Physics Vol.10 No.3

Cadmium telluride (CdTe) thin films were grown on sapphire c-face single-crystal substrates by vacuum evaporation. Prior to growing the CdTe thin films, conducting thin films of Ni, Mo, Ti and titanium nitride (TiN) were grown on the sapphire substrates. The crystallinities and photoluminescence (PL) properties of the CdTe thin films grown on the various conducting thin films were investigated and they were compared with those of CdTe thin films grown directly on sapphire substrates without a conducting thin film. CdTe thin films with relatively high crystallinities were obtained when Ti and TiN were used as the conducting thin film. Therefore, the PL properties of the CdTe thin films on such conducting thin films were not inferior to those of the CdTe thin film grown directly on the sapphire substrate. The effect of the Cd and Te supply ratio on the properties of the CdTe thin films was also investigated. The CdTe thin films had much higher crystallinities when they were grown in Te-rich conditions than in Cd-rich conditions.

Effects of Mn doping on BaTiO3 thin films grown on highly oriented pyrolytic graphite substrates

이은미,안윤호,손종영 한국물리학회 2020 Current Applied Physics Vol.20 No.6

We report multiferroelectric properties of Mn-doped BaTiO3 (MBTO) thin films on highly oriented pyrolytic graphite (HOPG) substrates. The MBTO thin films were grown on the HOPG substrate by pulse laser deposition. For comparison purpose, undoped BaTiO3 (BTO) thin films were also prepared under same experimental conditions. The BTO and MBTO thin films were polycrystalline, indicating that the MBTO thin film has better crystallinity than the BTO thin film. The leakage current of the MBTO thin film was reduced due to the Mn doping substitution. In addition, the MBTO thin film exhibited better than the BTO thin film in ferroelectric and magnetic behaviors. We suggest that the Mn doping bring about the improvements of ferroelectric and ferromagnetic properties of the BTO thin films. Based on atomic force microscopy (AFM) and conducting AFM (CAFM) studies, the grain size of MBTO thin film was much larger than that of BTO thin film.

Thermal Evaporation 법에 의해 제조된 WO3 박막과 NiO-WO3 박막의 전기적 특성에 관한 연구

나은영,나동명,박진성 한국전기화학회 2005 한국전기화학회지 Vol.8 No.1

WO3 and NiO-WO3 thin films were deposited on a Si (100) substrate by using high vacuum thermal evaporation. The effects of various film thicknesses on the surface morphology WO3 and NiO-WO3 thin films were investigated. X-ray diffraction (XRD), Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the deposited films. The results suggest that as WO3 thin films became thick, certain size of grain grew. On the other hand, their grain grew up to a certain size(?) NiO-dopint to WO3 thin films inhibited the grain growth five times less than undoped WO3 thin films. doping This results show that NiO dope inhibited the grain growth of WO3 thin films. Also, the variation of doping growing NOx sensitivity(RNOx/Rair) to the thickness of WO3 and NiO-WO3 thin films were measured according to the thickness change of thin films and the working temperature of sensor in 5 ppm NOx gas. As a result, NiO-WO3 thin films showed more excellent properties than WO3 thin films for NOx sensitivity.

RF 스퍼터법을 이용한 Li2MnSiO4 리튬 이차전지 양극활물질 박막 제조 및 전기화학적 특성

채수만,심중표,선호정 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.7

In this study, Li2MnSiO4 cathode material and LiPON solid electrolyte were manufactured into thin films and the possibility of their utilization in thin film batteries was researched. when the RTP treatment was performed after Li2MnSiO4 cathode thin film deposition on the SUS substrate by a sputtering method, a β-Li2MnSiO4 cathode thin film was successfully manufactured. The LiPON solid electrolyte was prepared by a reactive sputtering method using a Li3PO4 target and N2 gas, and a homogeneous and flat thin film was deposited on a Li2MnSiO4 cathode thin film. In order to evaluate the electrochemical properties of the Li2MnSiO4 cathode thin films, coin cells using only a liquid electrolyte were prepared and the charge/discharge test was conducted. As a result, the amorphous thin film of RTP treated at 600℃ showed the highest initial discharge capacity of about 60 μAh/cm2. In the cases of the coin cells using liquid/solid double electrolyte, the discharge capacities of the Li2MnSiO4 cathode thin films were comparable to those without solid LiPON electrolyte. It was revealed that Li2MnSiO4 cathode thin films with LiPON solid electrolyte were applicable in thin film batteries. 본 연구에서 고용량 양극 재료인 Li2MnSiO4과 고체전해질 LiPON을 박막화하였으며, 박막전지에 사용 가능성을 조사하였다. SUS 기판 상에 Li2MnSiO4 양극박막을 rf 스퍼터링으로 증착한 후 RTP 처리하였을 때, β-Li2MnSiO4 양극박막이 성공적으로 제조되었다. LiPON 고체전해질은 Li3PO4 타겟과 N2 가스를 사용하여 반응성 스퍼터링으로 준비되었으며, 균일하고 평탄한 박막이 Li2MnSiO4 양극박막 상에 증착되었다. Li2MnSiO4 양극 박막의 전기 화학적 성질을 평가하기 위하여 액체 전해질만을 사용하는 코인 셀을 제조하여 충,방전 시험을 수행하였다. 그 결과, 600 ℃에서 RTP 처리된 비정질 박막은 약 60 μAh/cm2의 가장 높은 초기 방전 용량을 보였다. 액체/고체 이중 전해질을 사용하는 코인 셀의 경우, Li2MnSiO4 양극 박막의 방전 용량은 고체 LiPON 전해질을 사용하지 않은 것과 비교할만 하였다. LiPON 고체 전해질을 갖는 Li2MnSiO4 음극 박막은 박막 전지로의 적용 가능성을 확인하였다.

그림자효과를 이용하여 증착한 타이타늄 박막의 미세구조 및 형상

한창석,진성윤,권혁구,Han, Chang-Suk,Jin, Sung-Yooun,Kwon, Hyuk-Ku 한국재료학회 2019 한국재료학회지 Vol.29 No.11

In order to observe the microstructure and morphology of porous titanium -oxide thin film, deposition is performed under a higher Ar gas pressure than is used in the general titanium thin film production method. Black titanium thin film is deposited on stainless steel wire and Cu thin plate at a pressure of about 12 Pa, but lustrous thin film is deposited at lower pressure. The black titanium thin film has a larger apparent thickness than that of the glossy thin film. As a result of scanning electron microscope observation, it is seen that the black thin film has an extremely porous structure and consists of a separated column with periodic step differences on the sides. In this configuration, due to the shadowing effect, the nuclei formed on the substrate periodically grow to form a step. The surface area of the black thin film on the Cu thin plate changes with the bias potential. It has been found that the bias of the small negative is effective in increasing the surface area of the black titanium thin film. These results suggest that porous titanium-oxide thin film can be fabricated by applying the appropriate oxidation process to black titanium thin film composed of separated columns.

RF 스퍼터법을 이용한 Li₂MnSiO₄ 리튬 이차전지 양극활물질 박막 제조 및 전기화학적 특성

채수만,심중표,선호정,Chae, Suman,Shim, Joongpyo,Sun, Ho-Jung 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.7

In this study, $Li_2MnSiO_4$ cathode material and LiPON solid electrolyte were manufactured into thin films, and the possibility of their use in thin-film batteries was researched. When the RTP treatment was performed after $Li_2MnSiO_4$ cathode thin-film deposition on the SUS substrate by a sputtering method, a ${\beta}-Li_2MnSiO_4$ cathode thin film was successfully manufactured. The LiPON solid electrolyte was prepared by a reactive sputtering method using a $Li_3PO_4$ target and $N_2$ gas, and a homogeneous and flat thin film was deposited on a $Li_2MnSiO_4$ cathode thin film. In order to evaluate the electrochemical properties of the $Li_2MnSiO_4$ cathode thin films, coin cells using only a liquid electrolyte were prepared and the charge/discharge test was conducted. As a result, the amorphous thin film of RTP treated at $600^{\circ}C$ showed the highest initial discharge capacity of about $60{\mu}Ah/cm^2$. In cases of coin cells using liquid/solid double electrolyte, the discharge capacities of the $Li_2MnSiO_4$ cathode thin films were comparable to those without solid LiPON electrolyte. It was revealed that $Li_2MnSiO_4$ cathode thin films with LiPON solid electrolyte were applicable in thin film batteries.

2 Dimensional Voltage Distribution Measurement of YBCO Thin Film during S/N transition

Mori, Masato,Nishioka, Hideyoshi,Baba, Jumpei,Nitta, Tanzo,Kumagai, Toshiya,Shibuya, Masatoyo The Korean Institute of Electrical Engineers 2011 The Journal of International Council on Electrical Vol.1 No.2

The process of the resistance generation in a YBCO thin film during the S/N transition used in resistive type fault current limiters has not been clarified completely. During the process, a thin film may be broken by overheat. Understanding the process of the resistance generation would lead to prevent thin films from this burnout. In this paper, the voltage distribution of a YBCO thin film during the S/N transition is measured by probes arranged 2 dimensionally on a thin film to understand how the normal transition area on a YBCO thin film expand. The voltage probes are placed in a matrix of 3 times 10 on a 30-by-210 millimeter YBCO thin film. A sinusoidal wave current whose amplitude is several hundreds ampere flows into the thin film connected with a parallel resistance. It is observed from these measurements that a narrow normal conducting state band vertical to the current appears first, and this band expands along the current. The critical current of the area on the thin film where the normal conducting state band appears first is the lowest along the thin film. This band is considered to have a great influence on the resistance generation of the YBCO thin film.