• Title/Summary/Keyword: Hydrogen annealing

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Annealing Effect on the Photoluminescence of Si Nanocrystallites Thin Films (후열처리에 따른 실리콘 나노결정 박막의 광학적 특성 변화 연구)

  • Jeon, Gyeong-A;Kim, Jong-Hun;Choe, Jin-Baek;Lee, Sang-Ryeol
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.51 no.6
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    • pp.236-239
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    • 2002
  • Si nanocrystallites thin films on P-type (100) Si substrate have been fabricated by pulsed laser deposition using a Nd:YAG laser. After deposition, samples were annealed in several environmental gases ;It the temperature range of 400 to $800^{\circ}C$ Hydrogen passivation was then performed in the forming gas (95 % $N_2$ + 5 % $H_2$) for 1 hr. Strong violet-indigo photoluminescence has been observed at room temperature on nitrogen ambient-annealed Si nanocrystallites. We report the variation of photoluminescence (PL) properties of Si thin films by changing annealing temperatures and by using hydrogen passivation. The results could suggest that the origin of violet-indigo PL should be related to the Quantum size effect of Si nanocrystallite.

Hydrogen Annealing effect on the dielectric properties of $(Pb_{0.72}La_{0.28})Ti_{0.93}O_3$ thin film

  • Lee, Eun-Sun;Chung, Hyun-Woo;Lim, Sung-Hoon;Lee, Sang-Yeol
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.41-43
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    • 2004
  • Dielectric thin films of $(Pb_{0.72}La_{0.28})Ti_{0.93}O_3$ were deposited on $Pt(111)/Ti/SiO_2/Si$ substrates in situ by pulsed laser deposition(PLD) and annealed with different gases which are forming gas and oxygen gas, respectively. The diffusion of hydrogen into the ferroelectric film was caused by annealing process and resulted in the destruction of polarization. The dielectric properties of forming gas annealed PLT thin films, which are dielectric constant, ferroelectric characteristic, and leakage current characteristics, were degraded

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Characteristics of Pd-doped WO3 thin film for hydrogen gas sensor (수소 센서용 Pd 첨가한 WO3 박막의 특성)

  • Kim, Gwang-Ho;Choi, Gwang-Pyo;Kwon, Yong;Park, Jin-Seong
    • Journal of Sensor Science and Technology
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    • v.15 no.2
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    • pp.120-126
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    • 2006
  • Physicochemical and electrical properties for hydrogen gas sensors based on Pd-deposited $WO_3$ thin films were investigated as a function of Pd thickness, annealing temperature, and operating temperature. $WO_3$ thin films were deposited on an insulating material by thermal evaporator. XRD, FE-SEM, AFM, and XPS were used to evaluate the crystal structure, microstructure, surface roughness, and chemical property, respectively. The deposited films were grown $WO_3$ polycrystalline with rhombohedral structure after annealing at $500^{\circ}C$. The addition effect of Pd is not the crystallinity but the suppression of grain growth of $WO_3$. Pd was scattered an isolated small spherical grain on $WO_3$ thin film after annealing at $500^{\circ}C$ and it was agglomerated as an irregular large grain or diffused into $WO_3$ after annealing at $600^{\circ}C$. 2 nm Pd-deposited $WO_3$ thin films operated at $250^{\circ}C$ showed good response and recovery property.

Hydrogen Degradation of Pt/SBT/Si, Pt/SBT/Pt Ferroelectric Gate Structures and Degradation Resistance of Ir Gate Electrode (Pt/SBT/Si, Pt/SBT/Pt 강유전체 게이트 구조에서 수소 열화 현상 및 Ir 게이트 전극에 의한 열화 방지 방법)

  • 박전웅;김익수;김성일;김용태;성만영
    • Journal of the Microelectronics and Packaging Society
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    • v.10 no.2
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    • pp.49-54
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    • 2003
  • We have investigated the effects of hydrogen annealing on the physical and electrical properties of $SrBi_{2}Ta_{2}O_9(SBT)$ thin films in the Pt/SBT/Si (MFS) structure and Pt/SBT/Pt (MFM) one, respectively. The microstructure and electrical characteristics of the SBT films were deteriorated after hydrogen annealing due to the damage of the SBT films during the annealing process. To investigate the reason of the degradation of the SBT films in this work, in particular, the effect of the Pt top electrodes, SBT thin films deposited on Si, Pt, respectively, were annealed with the same process conditions. From the XRD, XPS, P-V, and C-V data, it was seen that the SBT itself was degraded after $H_2$ annealing even without the Pt top electrodes. In addition, the degradation of the SBT films after $H_2$ annealing was accelerated by the catalytic reaction of the Pt top electrodes which is so-called hydrogen degradation. To prevent this phenomenon, we proposed the alternative top electrode material, i.e. Ir, and the electrical properties of the SBT thin films were examined in the $Ir/IrO_2/SBT/IrO_2$ structures before and after the H$_2$ annealing and recovery heat-treatment processes. From the results of the P-V measurement, it could be concluded that Ir is one of the promising candidate as the electrode material for degradation resistance in the MFM structure using SBT thin films.

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Changes fo Electric conductivity of Amorphous Silicon by Argon radical Annealing

  • Lee, Jae-Hee
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.63-63
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    • 1999
  • The stability of hydrogenated amorphous silicon (a-Si:H) films under the light soaking are very important since the applications of a-Si:H films are solar cells, color sensors, photosensors, and thin film transistors(TFTs). We found the changes of the electric conductivity and the conductivity activation energy (Ea) of a-Si:H films by argon radical annealing. The deposition rate of a-Si:H films depends on the argon radical annealing time. The optical band gap and the hydrogen contents in the a-Si:H films are changes along the argon radical annealing time. We will discuss the microscopic processes of argon radical annealing in a-si:H films.

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Metal-Semiconductor-Metal Photodetector Fabricated on Thin Polysilicon Film (다결정 실리콘 박막으로 구성된 Metal-Semiconductor-Metal 광검출기의 제조)

  • Lee, Jae-Sung;Choi, Kyeong-Keun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.5
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    • pp.276-283
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    • 2017
  • A polysilicon-based metal-semiconductor-metal (MSM) photodetector was fabricated by means of our new methods. Its photoresponse characteristics were analyzed to see if it could be applied to a sensor system. The processes on which this study focused were an alloy-annealing process to form metal-polysilicon contacts, a post-annealing process for better light absorption of as-deposited polysilicon, and a passivation process for lowering defect density in polysilicon. When the alloy annealing was achieved at about $400^{\circ}C$, metal-polysilicon Schottky contacts sustained a stable potential barrier, decreasing the dark current. For better surface morphology of polysilicon, rapid thermal annealing (RTA) or furnace annealing at around $900^{\circ}C$ was suitable as a post-annealing process, because it supplied polysilicon layers with a smoother surface and a proper grain size for photon absorption. For the passivation of defects in polysilicon, hydrogen-ion implantation was chosen, because it is easy to implant hydrogen into the polysilicon. MSM photodetectors based on the suggested processes showed a higher sensitivity for photocurrent detection and a stable Schottky contact barrier to lower the dark current and are therefore applicable to sensor systems.

Increased Chemical Durability by Annealing of SPEEK Membrane for Polymer Electrolyte Fuel Cells (고분자 전해질 연료전지용 SPEEK 막의 어닐링에 의한 화학적 내구성 향상)

  • MI-HWA LEE;DONGGEUN YOO;HYE-RI LEE;IL-CHAI NA;KWONPIL PARK
    • Transactions of the Korean hydrogen and new energy society
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    • v.34 no.6
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    • pp.673-681
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    • 2023
  • Hydrocarbon-based polymer membranes to replace perfluorinated polymer membranes are being continuously researched. However, hydrocarbon-based membranes have a problem in that they are less durable than fluorine-based membranes. In this study, we sought to compare the annealing effect to improve the durability of sulfonated poly(ether ether ketone) (SPEEK). After membranes formation, thermogravimetric analysis and tensile strength were measured to compare changes in membranes properties due to annealing. After manufacturing the membrane and electrode assembly (MEA), the initial performance and chemical durability was compared with unit cell operation. During the 24-hour annealing process, the strength increased due to the increase in-S-O-S-crosslinking, and the sulfonic acid group decreased, leading to a decrease in I-V performance. By annealing, the hydrogen permeability was reduced to less than 1/10 of that of the nafion membrane, and as a result, open circuit voltage (OCV) and durability was improved. The SPEEK membranes annealed for 24 hours showed higher durability than the nafion 211 membranes of the same thickness.

The Effect of Hydrogen on the Tribological Properties of Hydrogenated Amorphous Carbon Films

  • Shin, Jong-Han;Lim, Dae-Soon
    • The Korean Journal of Ceramics
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    • v.3 no.2
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    • pp.96-100
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    • 1997
  • Hydrogenated amorphous carbon films were deposited on silicon substrates by using an RF PECVD. The hydrogen/methane ratio was varied from 50% to 88% to study the effect of hytdrogen in the film on the tribological properties. The friction and wear behaviors of the deposited films were investigated by ball-on-disk type wear tester. FT-IR spectra were used to characterize the structure of the films. Tribological properties of carbon films were correlated with their structure such as ratio of "polymer-like" stretching type and that of sp2 bonding. The result showed that the annealing caused a decrease in the amount of wear of contacted $Si_3N_4$ balls and a increase in the coefficient of friction. Possible explanation for annealing effect was discussed by the hydrogen desorption.esorption.

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Preparation of Sr2FeMoO6 Thin Films by RF Magnetron Sputtering and Their Electrical Conduction Properties (RF 스퍼터법을 이용한 Sr2FeMoO6 박막 제조 및 전기전도 특성)

  • Ryu, Hee-Uk;Sun, Ho-Jung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.12
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    • pp.966-972
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    • 2010
  • Single-phase $Sr_2FeMoO_6$ thin films were produced by RF magnetron sputtering for use as electrodes in integrated sensors and found to be good conductors at room temperature. The films were deposited from a powder-type sputtering target under various conditions, and were crystallized by annealing. Elimination of $O_2$ gas during deposition, by the use of a solely Ar sputtering gas under a working pressure as low as possible, and vacuum annealing were important to promote the $Sr_2FeMoO_6$ phase. However, oxygen exclusion from sputtering and annealing was not enough to yield single-phase $Sr_2FeMoO_6$: hydrogen annealing was also required. Film production was optimized by varying the deposition parameters and hydrogen annealing conditions. The film had good electrical conduction, with a low resistivity of $1.6{\times}10^{-2}\Omega{\cdot}cm$ at room temperature.

Activation of Implanted tons by Microwave Annealing (마이크로 웨이브를 이용한 이온의 활성화 방법에 관한 연구)

  • Kim, Cheon-Hong;Yoo, Juhn-Suk;Park, Cheol-Min;Han, Min-Koo
    • Proceedings of the KIEE Conference
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    • 1997.07d
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    • pp.1630-1632
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    • 1997
  • We have investigated activation phenomena of implanted ions on silicon wafers using microwave(2.45GHz). It is found that the higher concentration of impurities makes the better activation effects by microwave annealing. We have exposed poly-Si TFTs by microwave in order to anneal and improved the device performance. Microwave activates source/drain ions and lowers the contact resistance so that the current of the poly-Si TFTs increases. In addition, the leakage current of hydrogen passivated poly-Si TFTs is decreased after microwave annealing, due to the diffusion of hydrogen ions and curing the defects in the poly-Si active channel.

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