• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.747-751
• /
• 2006

The hydrogenated amorphous silicon thin film transistor (a-Si:H TFT) with copper as source and drain electrode has been fabricated to obtain its transfer characteristics and stressed with positive and negative bias to investigate the instability variation comparing to conventional MoW-Al based TFT device. The results show that there is no copper diffusion into active layer of a-Si:H TFT, even during the thermal process. In addition, a 15-inch XGA a Si:H TFT LCD display utilizing Cu as gate electrodes has been developed.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.1526-1529
• /
• 2005

Zinc oxide films have been actively investigated as transparent electrode materials for display. We report the effect of the working pressures on electro-optical properties of Al-doped ZnO thin films deposited by d.c. magnetron sputtering. The resistivity of the ZnO thin films was depended on atomic bombardment effect by working pressure.

• Journal of Information Display
• /
• v.10 no.1
• /
• pp.24-27
• /
• 2009

A simple nonalkoxide sol-gel route for depositing an Al-doped ZnO thin film on a glass substrate was derived in this study. The initial Al dopant concentration in the sol-gel preparation varied and ranged from 0 to 5%. The sol-gel-derived thin films showed c-plane preferred crystallization of their hexagonal phase, with nanosized grain structures. First and second post-heat-treatments were carried out to improve the film’s electrical resistivity. The carrier density and the Hall mobility were measured and discussed to explain the electrical resistivity. The optical transmittance within the visible range showed compatible properties, which indicates the possible use of A1-doped ZnO as a transparent electrode in flat panel displays.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.23 no.5
• /
• pp.424-428
• /
• 2010

This paper describes the design and analysis of AlN piezoelectric micro energy harvester. The harvester was designed to convert ambient vibration energy to electrical power as a AlN piezoelectric material compatible with CMOS (complementary metal oxide semiconductor) process. To cut off the leakage current, AlN was used as the insulating layer. Also, Mo was used for the excellent c-axis crystal growth as the bottom electrode. The AlN harvester which it has the low operating frequency was designed by using the ANSYS FEA (finite element analysis). From the simulation results, the resonance frequency of designed model is about 360 Hz and analyzed the bending mode, displacement and expectation output.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2000.01a
• /
• pp.11-12
• /
• 2000

An 18.1" Thin Film Transistor Liquid Crystal Display (TFT LCD) monitor adopting high brightness In Plane Switching (IPS) technology was realized. While conventional IPS structure used a Chromium (Cr) and Molybdenum (Mo) for a drain electrode, Indium Tin Oxide (ITO) was proposed and verified in this paper. Black sticky micropeal spacers were introduced for the reduction of light scattering phenomena, which was observed at dark room with the conventional micropeal spacers. With the proposed method, more than 10 % aperture ratio was increased and the excellent image quality was obtained.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.12S
• /
• pp.1224-1231
• /
• 2003

This paper reports on the air-gap type thin film bulk acoustic wave resonator(FBAR) using ultra thin wafer with thickness of 50$\mu\textrm{m}$. It was fabricated to realize a small size devices and integrated objects using MEMS technology for flexible microsystems. To reduce a error of experiment, MATLAB simulation was executed using material characteristic coefficient. Fabricated thin FBAR consisted of piezoelectric film sandwiched between metal electrodes. Used piezoelectric film was the aluminum nitride(AlN) and electrode was the molybdenum(Mo). Thin wafer was fabricated by wet etching and dry etching, and then handling wafer was used to prevent damage of FBAR. The series resonance frequency and the parallel frequency measured were 2.447㎓ and 2.487㎓, respectively. Active area is 100${\times}$100$\mu\textrm{m}$$^2$.Q-factor was 996.68 and K$^2$$\_$eff/ was 3.91％.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.1061-1064
• /
• 2009

Through dark injection space-charge-limited current (DI-SCLC) and trap-free SCLC measurements, it has been demonstrated that an indium tin oxide (ITO)/buckminsterfullerene ($C_{60}$) electrode can form a quasi-Ohmic contact with N, N'-bis (naphthalen-1-yl)-N, N'-bis(phenyl) benzidine (NPB). The DI-SCLC results show a clear peak current along with a shift of the peak position as the field intensity varies, implying an Ohmic (or quasi-Ohmic) contact. A theoretical simulation of the SCLC also shows that ITO/$C_{60}$ forms an Ohmic contact with NPB. The Ohmic contact makes it possible to estimate the NPB hole mobility through the use of both DI-SCLC and trap-free SCLC analysis. This also contributes to a reduction in power consumption.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.05a
• /
• pp.295-299
• /
• 1999

The (S $r_{1-x}$C $a_{x}$)Ti $O_3$(SCT) thin films are deposited on Pt-coated electrode(Pt/TiN/ $SiO_2$/ Si) using RF sputtering method with substitutional contents of Ca. The maximum grain of thin films is obtained by substitution of Ca at 15[mol%]. The dielectric constant was increased with increasing the substitutional contents of Ca, while it was decreased if the substitutional contents of Ca exceeded over 15[mo1%]. The dielectric constant changes almost linearly in temperature ranges of -80~ +90[$^{\circ}C$]. The temperature properties of the dielectric loss have a stable value within 0.02 independent of the substitutional contents of Ca. All SCT thin films used in this study show the phenomena of dielectric relaxation with the increase of frequency, and the relaxation frequency is observed above 200(kHz).)..

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2009.05a
• /
• pp.22.1-22.1
• /
• 2009

차세대 CMOS 공정에서 유전상수가 높은 게이트 절연막과 함께 게이트 전극이 관심을 끌고 있다. 게이트 전극은 전도도가 높아야 하고 p-MOS, n-MOS에 맞는 일함수를 가져야 하며 열적 특성이 안정해야 한다. 탄탈룸 계열 탄화물이나 질화물은 게이트 전극으로 관심을 끌고 있는 물질이며 이를 원자층 화학증착법으로 박막화 하는 공정이 관심을 끌고 있다. 원자층 화학공정에서는 전구체의 역할이 중요하며 이의 기상반응 메카니즘, 표면 반응 메카니즘을 제대로 이해해야 한다. 본 연구에서는 TBTDET (tert-butylimido tris-diethylamido tantalum) 전구체의 반응 메커니즘을 FTIR(Fourier Transform Infrared)을 이용해 진단하였다. 또한 수소, 암모니아, 메탄을 이용한 열화학 원자층 증착, 플라즈마 원자층 증착 공정을 수행하여 박막을 얻고 이들의 특성을 평가하였다. 각 공정에 따라 반응 메커니즘이 달라지고 박막의 조성이 달라지며 또한 박막의 물성도 달라진다. 특히 박막에 형성되는 TaC, TaN, Ta3N5, Ta2O5 (증착 후 산소의 유입에 의해 형성됨) 등의 조성이 공정에 따라 달라지며 박막의 물성도 달라진다. 반응메카니즘의 연구를 통해 각 공정에서 어떠한 조성의 박막이 얻어지는 지를 규명하였고 박막의 밀도에 따라 산소유입량이 어떻게 달라지는 지를 규명하였다.

• Journal of the Korean Professional Engineers Association
• /
• v.30 no.3
• /
• pp.43-51
• /
• 1997

Vacuum tubes are electron tubes in which the motion of electrons are utilized. There are many kinds of vacuum tubes, e.g. diode tubes, triode tubes, pentodes. muti-tubes and etc. Generally accommodated in glass tube, its eletrodes can be seen easily from outside and it easy to understand. In 1884 Edison discovered a current flow in the vacuum tube. He could not, however, explain this phenomenon. This is called Edison effect. In 1904 Fleming developed the backup for the practical diode theory. The most important milestone in this early history of electronics came in 1906 when De Forest put a third electrode (a grid) into the above, and thus invented the triode tube. It is 90 years since the triode was invented by De Forest (as of 1996) and 100 years (centennial also as of 1996) since the specific electric change e/mo$_0$ ≒ 1.7589 ${\times}$ 1011 (C/kg) was confirmed by the English scientist Thomson in 1896. On the occasion of the 90th and 100th anniversary of these inventions and discovery, E would like to describe the rise and 1111 of the vacuum tubes and the current status of these tubes.