http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
펄스 DC 마그네트론 스퍼터링법에 의한 ZnO:Al 박막 증착시 펄스 주파수의 영향
고형덕,이충선,태원필,서수정,김용성 한국세라믹학회 2004 한국세라믹학회지 Vol.41 No.6
AZO (Al-doped ZnO) thin films were deposited on glass by pulsed magnetron sputtering method, and their structural, electrical and optical properties were investigated. XRD patterns showed that a highly c-axis preferred AZO film was grown in perpendicular to the substrate when pulse frequency of 30 ㎑ was applied to the target. Microstructure of thin films showed that the fibrous grain of tight dome shape was grown. The deposition rate decreased linearly with increase of pulse frequency, and the lowest resistivity was 8.67${\times}$10$\^$-4/ $\Omega$-cm for the film prepared at pulse frequency of 30 ㎑. The optical transmittance spectra of the films showed a very high transmittance of 85∼90%, within visible wavelength region and exhibited the absorption edge of about 350 nm. The characteristics of the low electrical resistivity and high optical transmittance of AXO films suggested a possibility for the application to transparent conducting oxides. 펄스 do 마그네트론 스퍼터링법에 의해 유리 기판 위에 AZO(Al-doped ZnO) 박막을 제조하여 박막의 구조적, 전기적 및 광학적 특성을 조사하였다. 본 연구를 위해 l.0 at% Al이 도핑 된 ZnO세라믹 타켓을 사용하였다. XRD 분석을 통하여 30KHz의 펄스 주파수가 인가되었을 때 c축 배향성이 가장 우수하게 나타났고, 표면 형상 분석을 통하여 매우 치밀한 박막이 성장되었음을 알 수 있었다. 증착율은 펄스 주파수가 증가함에 따라 선형적으로 감소하였고, 30KHz의 펼스 주파수가 인가되었을 때 비저항은 8.67${\times}$$10^{-4}$ $\Omega$-cm의 가장 낮은 비저항을 나타내었으며, UV-vis. 투과율 측정결과, 평균 85% 이상의 높은 투과도를 나타내었다. 이러한 낮은 비저항 및 높은 광 투과도로 볼 때 AZO 박막은 투명 전도성 산화물 박막으로의 응용 가능성을 나타내었다.
서진덕,임교묵,이상민,안재현,홍석준,유형중,정석원,박선길,조동일,고형호 대한전자공학회 2013 Journal of semiconductor technology and science Vol.13 No.1
We describe a neural stimulator front-endwith arbitrary stimulation waveform generator andadaptive supply regulator (ASR) for visual prosthesis. Each pixel circuit generates arbitrary currentwaveform with 5 bit programmable amplitude. TheASR provides the internal supply voltage regulated tothe minimum required voltage for stimulation. Theprototype is implemented in 0.35 μm CMOS with HVoption and occupies 2.94 mm2 including I/Os.
서진덕 ( Jin Deok Seo ),임교묵 ( Kyo Muk Lim ),고형호 ( Hyoung Ho Ko ) 한국센서학회 2012 센서학회지 Vol.21 No.3
This paper presents frequency response compensation technique, and a self-oscillation circuit for capacitive microresonator with the compensation technique using programmable capacitor array, to compensate for the frequency response distorted by parasitic capacitances, and to obtain stable oscillation condition. The parasitic capacitances between the actuation input port and capacitive output port distort the frequency response of the microresonator. The distorted non-ideal frequency response can be compensated using two programmable capacitor arrays, which are connected between anti-phased actuation input port and capacitive output port. The simulation model includes the whole microresonator system, which consists of mechanical structure, transimpedance amplifier with automatic gain control, actuation driver and compensation circuit. The compensation operation and oscillation output of the system is verified with the simulation results.
졸-겔법에 의해 제조된 Al-Doped ZnO 박막의 후열처리 온도에 따른 전기 및 광학적 특성
고석배,최문순,고형덕,이충선,태원필,서수정,김용성,Ko, Seok-Bae,Choi, Moon-Sun,Ko, Hyungduk,Lee, Chung-Sun,Tai, Weon-Pil,Suh, Su-Jeong,Kim, Young-Sung 한국세라믹학회 2004 한국세라믹학회지 Vol.41 No.10
비등점이 낮은 용매인 isopropanol에 용질농도 0.7mol/$\iota$ Zn acetate를 용해시키고 dopant로 Al chloride를 첨가하여 균일하고 안정한 sol을 합성하였다. 졸-겔법에 의한 Al-doped ZnO(AZO) 박막의 제조시 $500\~700^{\circ}C$의 범위에서 후열처리 온도를 제어하여 박막의 전기 및 광학적 특성을 조사하였다. 후열처리 온도가 증가할수록 (002) 면으로의 c-축 결정배향성은 증가하였고, 박막 표면은 균일한 나노입자의 미세구조를 형성하였다. 광 투과도는 $650^{\circ}C$ 이하의 후열처리 온도에서 $86\%$이상이었으나, $700^{\circ}C$에서는 감소하였다. 박막의 전기 비저항 값은 $650^{\circ}C$ 이하에서 열처리 온도가 증가함에 따라 73에서 22$\Omega$-cm로 감소하였으나 $700^{\circ}C$에서 580$\Omega$-cm로 급격히 증가하였다. 후열처리 온도 $700^{\circ}C$에서 AZO 박막의 전기 및 광학적 특성의 열화는 XPS 분석결과, 박막 표면에 석출된 $Al_2O_3$ 상에 기인하였다. AZO 박막의 전기 및 광학적 특성 향상을 위한 최적의 후열처리 온도는 $600^{\circ}C$였다. Isopropanol of low boiling point was used as a solvent to prepare Al-doped ZnO(AZO) thin films. A homogeneous and stable sol was made from Zn acetate a solute whose mole concentration was 0.7mol/$\iota$ and Al chloride as a dopant. Al-doped ZnO thin films were prepared by sol-gel method as a function of post-heating temperature from 500 to $700^{\circ}C$ and the optical and electrical properties were investigated. The c-axis orientation along (002) plane was enhanced with the increasing of post-heating temperature and the surface morphology of the films showed a homogeneous and nano-sized microstructure. The optical transmittance of the films post-heated below $650^{\circ}C$ was over $86\%$, but decreased at $700^{\circ}C$. The electrical resistivity of the thin films decreased from 73 to 22 $\Omega$-cm as the post-heating temperature increased up to $650^{\circ}C$, but increased greatly to 580 $\Omega$-cm at $700^{\circ}C$. XPS analysis indicated that the deterioration of electrical and optical properties was attributed to the precipitation of $Al_2O_3$ phase on the surface of AZO thin film. This result suggests that the optimum post-heating temperature to improve electrical and optical properties is $600^{\circ}C$.