• Title, Summary, Keyword: Thermal evaporation

Search Result 751, Processing Time 0.054 seconds

A Study on the Development and Application of Thermal Evaporation Source (Thermal Evaporation 증발원 개발 및 응용에 관한 연구)

  • Kim, Kwan-Do
    • Journal of the Semiconductor & Display Technology
    • /
    • v.19 no.3
    • /
    • pp.19-22
    • /
    • 2020
  • The thermal evaporation source is used to prepare thin films by physical vapor deposition. Materials of metals, organic materials, were tested and explained for thermal evaporation experiments. The developed effusion cell performance depends on the type of deposition material, the size of the crucible, the performance of the reflector, etc. and the proper conditions were found by producing, comparing and analyzing several sets of effusion cell to quantitatively evaluate the performance of the cell. The effusion cell for thermal evaporation source is used to prepare thin films of Ag, Cu, Mg.

  • PDF

Homeotropic Alignment Effect of a Nematic Liquid Crystal on Oblique Deposited SiOx Thin-film with e-beam Evaporation

  • Choi, Dai-Seub
    • Transactions on Electrical and Electronic Materials
    • /
    • v.8 no.6
    • /
    • pp.274-277
    • /
    • 2007
  • In this study, liquid crystal(LC) aligning capabilities for homeotropic alignment on the $SiO_x$ thin film by electron beam evaporation method were investigated. Also, the control of pretilt angles and thermal stabilities of the nematic liquid crystal(NLC) treated on $SiO_x$ thin film were investigated. A high pretilt angle of about $86.5^{\circ}$ was obtained, and also the suitable pretilt angle of the NLC on the $SiO_x$ thin film at $10{\sim}50nm$ thickness with e-beam evaporation can be achieved. The uniform LC alignment and good thermal stabilities on the $SiO_x$ thin film surfaces with electron beam evaporation can be achieved. It is considered that the LC alignment on the $SiO_x$ thin film by electron beam evaporation is attributed to elastic interaction between LC molecules and micro-grooves at the $SiO_x$ thin film surface created by evaporation.

Liquid crystal aligning capabilities for vertical aligned NLC on the $CeO_x$ thin film layer with thermal evaporation

  • Han, Jin-Woo;Kim, Mi-Jung;Kim, Jong-Yeon;Han, Jeong-Min;Kim, Young-Hwan;Kim, Jong-Hwan;Kim, Byoung-Yong;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.371-371
    • /
    • 2007
  • In this study, liquid crystal (LC) aligning capabilities for vertical alignment on the $CeO_x$ thin film by thermal evaporation method were investigated. Also, the control of pretilt angles and thermal stabilities of the NLC treated on $CeO_x$ thin film were investgated. The uniform LC alignment on the $CeO_x$ thin film surfaces and good thermal stabilities with thermal evaporation can be achieved. It is considerated that the LC alignment on the $CeO_x$ thin film by thermal evaporation is attributed to elastic interaction between LC molecules and micro-grooves at the $CeO_x$ thin film surface created by evaporation. In addition, it can be achieved the good electro-optical (EO) properties of the VA-LCD on $CeO_x$ thin film layer with oblique thermal evaporation.

  • PDF

Thermal evaporation을 이용해 성장 온도에 따른 ZnO nanorod의 특성

  • Lee, Hye-Ji;Kim, Dong-Yeong;Kim, Ji-Hwan;Kim, Hae-Jin;Son, Seon-Yeong;Kim, Jong-Jae;Kim, Hwa-Min
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.25-25
    • /
    • 2009
  • Zinc Oxide (ZnO) nanorod were grown on Si wafer by a thermal evaporation method at various temperatures. And their structure and optical properties were measured using Photoluminescence(PL), Scanning electron microscopy(SEM), and X-ray diffraction(XRD) analysis.

  • PDF

CENTRALLY PEAKED X-RAY SNRS : CLOUD EVAPORATION AND THERMAL CONDUCTION (X-선 중심 가광 초신성 잔해 : 성간운 증발과 열전도 모델)

  • CHOE SEUNG-URN;JUNG HYUN-CHUL;PARK BYEONG-GEON
    • Publications of The Korean Astronomical Society
    • /
    • v.14 no.2
    • /
    • pp.69-78
    • /
    • 1999
  • We present the results of one-dimensional numerical simulations of SNR evolution in the in­homogeneous medium considering the effects of the evaporation of the cloud and the thermal conduction. We have included the effects of changing evaporation rate as a function of cloud size and the ambient temperature so that the clouds could be evaporated completely before they reach the center of the SNR. The heat conduction markedly changes the density distribution in the remnant interior. To explain the observed morphologies of the centrally peaked X-ray SNRs(for example W44), the maximal thermal conduction is required. However, this is unlikely due to the magnetic field and the turbulent motion. The effects of the evaporation of the cloud and the thermal conduction described here may explain the class of remnants observed to have centrally peaked X-ray emmision.

  • PDF

Effect of Oxygen Pressure on the Morphology of ZnO Nanostructures Fabricated by Thermal Evaporation Technique (열 증발법에 의하여 제작된 ZnO 나노 구조의 형상에 미치는 산소 압력의 영향)

  • Lee, Jung-Hun;Lee, Geun-Hyoung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.25 no.11
    • /
    • pp.873-877
    • /
    • 2012
  • The effect of oxygen pressure in the synthesis of ZnO nanostructures through thermal evaporation of Zn powder was investigated. The thermal evaporation process was carried out in oxygen ambient for 1 hr at $1,000^{\circ}C$ under different pressures. The oxygen pressure was changed in range of 0.5 ~ 900 Torr. Any nanostructure was not formed on the specimens prepared at oxygen pressures lower than 10 Torr. When oxygen pressure was 100 Torr, ZnO nanowires were observed. With increasing the oxygen pressure to 500 Torr, the morphology of ZnO nanostructures changed from wire to tetrapod. For all the samples, room temperature photoluminescence spectra show a strong green emission peak at around 550 nm.

Characteristics of ZnO Nanowire Fabricated by Thermal Evaporation Method Depending on Different Temperatures and Oxygen Pressure (Thermal Evaporation법으로 제작한 ZnO 나노선의 온도와 산소유량에 따른 성장 특성)

  • Oh, Won-Seok;Jang, Gun-Eik
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.21 no.8
    • /
    • pp.766-769
    • /
    • 2008
  • Zinc oxide (ZnO) nanowires were prepared on Si substrates by a thermal evaporation method at different temperatures and $O_2$ pressure. Microstructural analysis of the obtained ZnO nanowires was performed by using transmission electron microscopy(TEM) and scanning electron microscopy(SEM). Phase analysis was done using X-ray diffraction(XRD). As the deposition temperature and oxygen pressure were increased, the diameter and length of ZnO nanowires had a tendency to increase. Based on TEM and XRD analyses, the nanowires are single crystalline in nature and consist of a single phase. According to the measurements, the ZnO nanowires grown at 1100$^{\circ}C$, Ar 50 sccm, $O_2$ 10 sccm have good properties.

Thermal Evaporation of Amorphous Chalcogenide on Single-mode Optical Fiber (단일 모드 광섬유 표면의 비정질 Chalcogenide 열 증착)

  • Hwang, Sung-Tae;Cho, Kyu-Man;Kang, Bong-Hoon;Joo, Gi-Tae
    • Journal of the Korean Ceramic Society
    • /
    • v.47 no.2
    • /
    • pp.142-145
    • /
    • 2010
  • We made a film of a few ${\mu}m$ thickness by evaporating $As_2S_3$ piece to perpendicularly cut optical fiber by thermal evaporation process. Linear refractive index(n) and linear absorption coefficient(k) of amorphous $As_2S_3$ are 2.525 and $1.727{\times}10^{-3}$, respectively. A surface roughness did not exceed 2 nm and a transmission spectrum showed that the sample of thermal evaporation was homogeneous.

Synthesis and Characterization of Alumina Composite Membrane by Al Evaporation and Thermal Oxidation (알루미늄의 진공증발과 열산화에 의한 알루미나 복합분리막의 제조 및 특성분석)

  • 이동호;최두진;현상훈
    • Journal of the Korean Ceramic Society
    • /
    • v.32 no.3
    • /
    • pp.349-358
    • /
    • 1995
  • The ceramic composite membrane was synthesized by thermal oxidation after evaporation of Al on the support prepared by slip casting process. Oxidation was performed at $700^{\circ}C$ and 80$0^{\circ}C$ under dry oxygen atmosphere. It was considered as optimum oxidation condition that the membrane showed a knudsen behaviro. A further oxidation resulted in an increase of gas permeability because top layer became densified. Then, a multi-layered composite membrane was synthesized through a sol-gel method, evaporation and thermal oxidation of Al coating processes. While the membrane was thermally stable up to 80$0^{\circ}C$, gas permeability was rapidly decreased even at a slight amount of deposition of Al.

  • PDF

ZnO Octahedron Fabricated by Thermal Evaporation Technique in Air (공기 중에서 열증발법에 의하여 제작된 정팔면체 ZnO 결정)

  • Lee, Geun-Hyoung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.26 no.4
    • /
    • pp.294-297
    • /
    • 2013
  • ZnO crystals with octahedral shape were synthesized by thermal evaporation technique. $ZnF_2$ powder was used as the source material. The thermal evaporation and oxidation of $ZnF_2$ powder was carried out for 1 hr at $1,000^{\circ}C$ in air under atmospheric pressure. SEM images showed that the ZnO crystals produced by oxidizing $ZnF_2$ vapor possessed a characteristic octahedral shape. XRD spectrum revealed that the ZnO octahedron had hexagonal wurtzite structure. In the room temperature photoluminescence spectrum, a strong green emission peak at around 510 nm was observed.