RF reactive magnetron sputtering으로 제조한 TiO₂ 박막의 구조 및 광학적 특성

강계원,이영훈,곽재천,이동구,정봉교,박성호,최병호,Gang, Gye-Won,Lee, Yeong-Hun,Gwak, Jae-Cheon,Lee, Dong-Gu,Jeong, Bong-Gyo,Park, Seong-Ho,Choe, Byeong-Ho 한국재료학회 2002 한국재료학회지 Vol.12 No.6

Titanium oxide films were prepared by RF reactive magnetron sputtering. The effect of sputtering conditions on structural and optical properties was investigated systemically as a function of sputtering pressure(5~20 mTorr) and $O_2/Ar$ flow ratio(0.08~0.4). The results of the X-ray diffraction showed that all films had only the anatase $TiO_2$ phase. At low sputtering pressure and $O_2/Ar$ flow ratio, the films had preferred orientations along [101] and [200] directions. As the sputtering pressure and $O_2/Ar$ flow ratio increased, the intensity of the 101 and 200 diffraction peaks decreased gradually. The microstructure of the sputtered films showed the fine grain size (20nm~50nm) and columnar microcrystals perpendicular to the substrate. With increasing the sputtering pressure and decreasing $O_2/Ar$ flow ratio, the sputtered films showed the more porous columnar structure. XPS analysis showed that stoichiometric $TiO_2$ films were deposited at 7 mTorr sputtering pressure and 0.2 $O_2/Ar$ flow ratio. The results of the X-ray diffraction showed that all films had only the anatase $TiO_2$ phase. Ellipsometeric analysis showed that the refractive index increased from 2.32 to 2.46 as the sputtering pressure decreased. The packing density calculated using the refractive index varied from 0.923 to 0.976, indicating that $TiO_2$films became denser as the sputtering pressure decreased.

Synthesis Ti–Si–N nanocomposite coating prepared by a hybrid system of double bending filtered vacuum arc source and magnetron sputtering

김도근,Igor Svadkovski,Seunghun Lee,Jong-Won Choi,Jong-Kuk Kim 한국물리학회 2009 Current Applied Physics Vol.9 No.3

In this work, various nanocomposite Ti–Si–N films have been deposited by hybrid coating system of double bending filtered vacuum arc source (DBFVAS) and magnetron sputtering techniques. Vacuum arc source has been used for the deposition of TiN and Si was incorporated by magnetron sputtering. The magnetic system of double bending filter consists of five solenoid coils and additional coil on the opposite side of vacuum chamber is supporting stabilization of the plasma flow onto substrate surface. Ti–Si–N film is deposited on the Si wafers and high speed steel (HSS) substrates with different Si content, which is controlled by magnetron current. As magnetron current increases from 0 to 1.5 A, Si content increases up to 18.2%. The deposition rate of Ti–Si–N coating layer is up to 17 nm/min. From the results Ti–Si–N coatings have been characterized as nanocomposites, consists of TiN crystallites and amorphous Si3N4. In this work, various nanocomposite Ti–Si–N films have been deposited by hybrid coating system of double bending filtered vacuum arc source (DBFVAS) and magnetron sputtering techniques. Vacuum arc source has been used for the deposition of TiN and Si was incorporated by magnetron sputtering. The magnetic system of double bending filter consists of five solenoid coils and additional coil on the opposite side of vacuum chamber is supporting stabilization of the plasma flow onto substrate surface. Ti–Si–N film is deposited on the Si wafers and high speed steel (HSS) substrates with different Si content, which is controlled by magnetron current. As magnetron current increases from 0 to 1.5 A, Si content increases up to 18.2%. The deposition rate of Ti–Si–N coating layer is up to 17 nm/min. From the results Ti–Si–N coatings have been characterized as nanocomposites, consists of TiN crystallites and amorphous Si3N4.

Analysis of magnetic field distribution in a cylindrical-type magnetron sputtering system

Bae, Kang-Yul,Yang, Young-Soo,Choi, Bum-Ho SAGE Publications 2013 PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGIN Vol.227 No.6

<P>The magnetic field distribution in magnetron sputtering processes has been verified to influence the collision of positive ions on the target, as well as the efficiency of the deposition onto the substrate. However, locally concentrated collision due to the distribution has also been known to lead to nonuniform erosion on the target, which deteriorates the efficiency of sputtering. In this study, a cylindrical magnetron sputtering system with a rotary-type target is proposed to improve the expected lifetime of the target by reducing the local erosion of target in the magnetron sputtering process. For the sputtering system, the magnetic field distribution over the target was analyzed with finite element method. Based on the analysis, the effect of the configuration of permanent magnets on the magnetic field distribution was investigated. The result of the analysis could be used to predict the region where concentration of positive ions occurs and thus to estimate the pattern of how the erosion on the target surface would occur for the proposed system. The results also reveal that the magnetic field distribution related to the erosion pattern could be controlled with the configuration of the permanent magnets.</P>

RF magnetron sputtering으로 제조된 강 유전체 $SrBi_2Ta_2O_9$ 박막의 열처리 온도에 따른 특성 연구

박상식,양철훈,윤순길,안준형,김호기 한국세라믹학회 1997 한국세라믹학회지 Vol.34 No.2

Bi층 SrBi2Ta2O9(SBT)박막을 상온에서 rf magnetron sputtering에 의해 Pt/Ti/SiO2/Si기판위에 증착한 다음 산소 분위기 하에서 1시간동안 75$0^{\circ}C$, 80$0^{\circ}C$, 85$0^{\circ}C$로 열처리하였다. 타겟은 박막내의 Bi와 Sr의 부족을 보상하기 위해 20mole%의 Bi2O3와 30mole%의 SrCO3를 과잉으로 넣어 사용하였으며, 80$0^{\circ}C$로 열처리한 박막의 조성은 Sr0.7Bi2.0Ta2.0O9.0이었다. 200nm의 두께를 갖는 이 SBT박막은 치밀한 미세구조와, 1MHz의 주파수에서 210의 유전상수, 0.05의 유전손실을 나타내었고, 또한 100 kMz에서 32$0^{\circ}C$의 큐리온도를 나타냈으며 그 온도에서의 유전상수는 314이었다. 이 SBT박막의 잔류분극(2Pr)과 항전계(2Ec)값은 각각 인가전압 3V에서 9.1$\mu$C/$\textrm{cm}^2$과 85kV/cm이었고, 5V의 bipolar pulse 하에서 1010 cycle까지 피로현상이 나타나지 않았으며, 누설전류 밀도는 150kV/cm에서 7$\times$10-7A/$\textrm{cm}^2$의 값을 보였다. rf magnetron sputtering 으로 제조된 SBT박막은 비휘발성 메모리 소자에의 응용이 가능하다. Bi-layered SrBi2Ta2O9(SBT) films were deposited on Pt/Ti/SiO2/Si sibstrates by rf magnetron sputt-ering at room temperature and then were annealed at 75$0^{\circ}C$, 80$0^{\circ}C$ and 85$0^{\circ}C$ for 1 hour in oxygen at-mosphere. The film composition of SrBi2Ta2O9 was obtained after depositing at room temperature and annealing at 80$0^{\circ}C$. Excess 20mole% Bi2O3 and 30 mole% SrCO3 were added to the target to compensate for the lack of Bi and Sr in SBT film. 200 nm thick SBT film exhibited and dense microstructure, adielectric constant of 210, and a dissipation factor of 0.05 at 1 MHz frequency. The films exhibited Curie temperature of 32$0^{\circ}C$ and a dielectric constant of 314 at that temperature under 100 kHz frequency. The remanent polarization(2Pr) and the coercive field(2Ec) of the SBT films were 9.1 $\mu$C/$\textrm{cm}^2$ and 85 kV/cm at an applied voltage of 3V, resspectively and the SBT film showed a fatigue-free characteristics up to 1010 cy-cles under 5V bipolar pulse. The leakage current density of the SBT film was about 7$\times$10-7A/$\textrm{cm}^2$ at 150 kV/cm. Fatigue-free SBT films prepared by rf magnetron sputtering can be suitable for application to non-volatile memory device.

RF-DC magnetron co-sputtering법에 의한 p-ZnO 박막의 성장

강승민,Kang Seung Min 한국결정성장학회 2004 한국결정성장학회지 Vol.14 No.6

p형 ZnO 에피 박막을 사파이어 기판의 (0001)면 상에 RF-DC magnet co-sputtering 법으로 성장시켰다. 약 120nm두께의 단결정상 박막을 성공적으로 얻어내었다. p형 ZnO를 만들기 위해서 Al 금속 타켓을 이용하여 DC 스퍼터링으로 $400^{\circ}C$와 $600^{\circ}C$에서 ZnO를 rf magnetron sputtering으로 증착하고, 동시에 Al의 doping을 행하였으며, 성장된 박막의 결정성과 광특성에 대하여 고찰하였다. p-ZnO films have been grown on (0001) sapphire substrates by RF-DC magnetron co-sputtering. The p-ZnO single crystalline thin films of the thickness about 120 nm were grown successfully. The dopant (Aluminum) was sputtered simultaneously from Al metal target by DC sputtering during rf-magnetron sputtering of ZnO at the substrate temperatures of $400^{\circ}C$ and $600^{\circ}C$ respectively. The crystallinity and optical properties of as-grown P-ZnO films have been characterized.

RF-enhanced DC-magnetron Sputtering of Indium Tin Oxide

Futagami, Toshiro,Kamei, Masayuki,Yasui, Itaru,Shigesato, Yuzo The Korean Ceramic Society 2001 The Korean journal of ceramics Vol.7 No.1

Indium tin oxide (ITO) films were deposited on glass substrates at $300^{\circ}C$ in oxygen/argon mixtures by RF-enhanced DC-magnetron sputtering and were compared to those by conventional DC magnetron sputtering. The RF enhancement was performed using a coil above an ITO target. X-ray diffraction measurements revealed that RF-enhanced plasma affected the preferred orientation and the crystallinity of the films. The resistivity of the films prepared by RF-enhanced DC-magnetron sputtering was almost constant at oxygen content lower than 0.3% and then increased sharply with increasing oxygen content. However the resistivity of the films by conventional sputtering has little dependence on the oxygen content. Those results can be explained on the basis of the incorporation of oxygen into the ITO films due to the RF enhancement.

Effect of Sputtering Power on the Nucleation and Growth of Cu Films Deposited by Magnetron Sputtering

Le, Minh-Tung,Sohn, Yong-Un,Lim, Jae-Won,Choi, Good-Sun The Japan Institute of Metals 2010 Materials Transactions Vol.51 No.1

<P>Cu thin films were deposited on Si(100) substrates using direct current (DC) magnetron sputtering. We focused on the effect of sputtering DC power on the electrical, structural properties, and the nucleation and growth of Cu films during the initial stage of sputtering. The Cu films deposited at higher sputtering power showed strong crystallinity, low electrical resistivity in comparison with the Cu films deposited at lower sputtering power. Concerning the nucleation and growth of Cu films during initial stage of magnetron sputtering, it was found that the progress of the nucleation and growth of the Cu films at higher sputtering is much faster than those of the Cu films at lower sputtering power even though they have a similar nucleation and growth mechanism, and their relation to resultant microstructure was confirmed by atomic force microscopy.</P>

RF-magnetron sputtering을 이용한 TiIZO 기반의 산화물 반도체에 대한 연구

우상현(Sanghyun Woo),임유성(Yooseong Lim),이문석(Moonsuk Yi) 대한전자공학회 2013 전자공학회논문지 Vol.50 No.7

본 연구에서는 TiInZn(TiIZO)를 채널층으로 하는 thin film transistors(TFTs)를 제작하였다. TiIZO층은 InZnO(IZO)와 Ti target을 이용하여 RF-magnetron co-sputtering system방식으로 상온에서 증착하였으며, 어떠한 열처리도 하지 않았다. Ti의 첨가가 어떠한 영향을 주는지 연구하기 위해 X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS) 분석을 시행하였으며, 전기적인 특성을 측정하였다. Ti의 첨가는 Ti target의 rf power 변화에 따라 달리하였다. Ti의 첨가가 전류점멸비에 큰 영향을 주는 것을 확인하였고, 이것은 Ti의 산화력이 In과 Zn보다 뛰어난 산소결함자리의 형성을 억제하기 때문이다. Ti의 rf power가 40W일 때 가장 좋은 특성을 나타냈으며, 전류점멸비, 전자이동도, 문턱전압, subthreshold swing이 각각 10?, 2.09[㎠/V·s]. 2.2[V], 0.492[V/dec.] 로 측정되었다. We fabricated thin film transistors (TFTs) using TiInZnO(TiIZO) thin films as active channel layer. The thin films of TiIZO were deposited at room temperature by RF-magnetron co-sputtering system from InZnO(IZO) and Ti targets. We examined the effects of titanium addition by X-ray diffraction, X-ray photoelectron spectroscopy and the electrical characteristics of the TFTs. The TiIZO TFTs were investigated according to the radio-frequency power applied to the Ti target. We found that the transistor on-off currents were greatly influenced by the composition of titanium addition, which suppressed the formation of oxygen vacancies, because of the stronger oxidation tendency of Ti relative to that of Zn or In. A optimized TiIZO TFT with rf power 40W of Ti target showed good performance with an on/off current ration greater than 10?, a field-effect mobility of 2.09[㎠/V·s], a threshold voltage of 2.2 [V] and a subthreshold swing of 0.492 [V/dec.]

RF Magnetron Sputtering공정에 의해 IT유리에 적층시킨 Silicon Nitride 박막의 특성

손정일,김광수,Son, Jeongil,Kim, Gwangsoo 한국재료학회 2020 한국재료학회지 Vol.30 No.4

Silicon nitride thin films are deposited by RF (13.57 MHz) magnetron sputtering process using a Si (99.999 %) target and with different ratios of Ar/N₂ sputtering gas mixture. Corning G type glass is used as substrate. The vacuum atmosphere, RF source power, deposit time and temperature of substrate of the sputtering process are maintained consistently at 2 ~ 3 × 10^-3 torr, 30 sccm, 100 watt, 20 min. and room temperature, respectively. Cross sectional views and surface morphology of the deposited thin films are observed by field emission scanning electron microscope, atomic force microscope and X-ray photoelectron spectroscopy. The hardness values are determined by nano-indentation measurement. The thickness of the deposited films is approximately within the range of 88 nm ~ 200 nm. As the amount of N₂ gas in the Ar:N₂ gas mixture increases, the thickness of the films decreases. AFM observation reveals that film deposited at high Ar:N₂ gas ratio and large amount of N₂ gas has a very irregular surface morphology, even though it has a low RMS value. The hardness value of the deposited films made with ratio of Ar:N₂=9:1 display the highest value. The XPS spectrum indicates that the deposited film is assigned to non-stoichiometric silicon nitride and the transmittance of the glass with deposited SiO₂-Si_xN_y thin film is satisfactory at 97 %.

RF Magnetron Sputtering을 이용하여 제작한 불용성 촉매전극의 해수전기분해 특성

이현석,김세기,석혜원,김진호,최헌진,정하익,Lee, Hyun-Seok,Kim, Sei-Ki,Seok, Hye-Won,Kim, Jin-Ho,Choi, Hun-Jin,Jung, Ha-Ik 한국재료학회 2012 한국재료학회지 Vol.22 No.2

Insoluble catalytic electrodes were fabricated by RF magnetron sputtering of Pt on Ti substrates and the performance of seawater electrolysis was compared in these electrodes to that is DSA electrodes. The Pt-sputtered insoluble catalytic electrodes were nearly 150 nm-thick with a roughness of $0.18{\mu}m$, which is 1/660 and 1/12 of these values for the DSA (dimensionally stable anodes) electrodes. The seawater electrolysis performance levels were determined through measurements of the NaOCl concentration, which was the main reaction product after electrolysis using artificial seawater. The NaOCl concentration after 2 h of electrolysis with artificial seawater, which has 3.5% NaCl normally, at current densities of 50, 80 and 140 mA/$cm^2$ were 0.76%, 1.06%, and 2.03%, respectively. A higher current density applied through the electrodes led to higher electrolysis efficiency. The efficiency reached nearly 58% in the Pt-sputtered samples after 2 h of electrolysis. The reaction efficiency of DSA showed higher values than that of the Pt-sputtered insoluble catalytic electrodes. One plausible reason for this is the higher specific surface area of the DSA electrodes; the surface cracks of the DSAs resulted in a higher specific surface area and higher reaction sites. Upon the electrolysis process, some Mg- and Ca-hydroxides, which were minor components in the artificial seawater, were deposited onto the surface of the electrodes, resulting in an increase in the electrical resistances of the electrodes. However, the extent of the increase ranged from 4% to 7% within an electrolysis time of 720 h.