• Title/Summary/Keyword: nitridation

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Effects of Magnesium Catalyst on the Nitridation of Aluminum Melt in the Synthesis of Aluminum Nitride Powder

  • Kim, Hyo-Jin;Kim, Sung-Hun;Lim, Sung-Min;Seo, Jong-Hyun;Lee, Kon-Bae;Lee, Jae-Chul;Ahn, Jae-Pyoung
    • Applied Microscopy
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    • v.44 no.2
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    • pp.79-82
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    • 2014
  • Aluminum nitride (AlN) powder was easily synthesized by the direct nitridation of Al melt containing ~20 wt.% Mg catalyst and the nitriding behavior was investigated by thermodynamic calculation and through observations of electron microscopy and X-ray diffraction. The addition of Mg catalyst decreased the nitriding temperature below $1,000^{\circ}C$, which is comparable to the high nitriding temperature of $1,400^{\circ}C$ required in carbothermal method. It was caused by a significant increase of the solubility of nitrogen gas due to the increase of Mg catalyst in Al melt. The dissolved nitrogen gas met Mg catalyst and was transformed into metastable $Mg_3N_2$. Finally the metastable phase reacted with Al to AlN.

A Study on the passivation of Si by Thermal Ammonia Nitroxide (Nitoxide막에 의한 표면 불활성화에 관한 연구)

  • Sung, Yung-Kwon;Choi, Jong-Il;Oh, Jae-Ha
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1988.05a
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    • pp.78-81
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    • 1988
  • Nitroxide films were made from the $NH_3$ gas nitridation of as-grown $SiO_2$. The electrical characterization results including C-V characteristics and BT stress generally indicate that the high field stress instability and insulator-substrate interfacial characteristics are improved by nitridation of $SiO_2$. A C-V technique was used to determine the surface state density $N_{55}$ and then $N_{55}$ in the nitroxide-substrate interface was $8{\times}10(/eVcm^2$). This $N_{55}$ is related with 1/f noise was revealed experimentally and relationship was plotted and 1/f noise characteristics were also improved by nitridation of of $SiO_2$By the results of measurements on these films show that very thin thermal silicon nitroxide films can be used as gate dielectrics for future highly scaled-down VLSI device.

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A Stacked Polusilicon Structure by Nitridation in N2 Atmosphere for Nano-scale CMOSFETs (나노 CMOS 소자 적용을 위한 질소 분위기에서 형성된 질화막을 이용한 폴리실리콘 적층 구조)

  • Ho, Won-Joon;Lee, Hi-Deok
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.11
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    • pp.1001-1006
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    • 2005
  • A new fabrication method is proposed to form the stacked polysilicon gate by nitridation in $N_2$ atmosphere using conventional LP-CVD system. Two step stacked layers with an amorphous layer on top of a polycrystalline layer as well as three step stacked layers with polycrystalline films were fabricated using the proposed method. SIMS profile showed that the proposed method would successfully create the nitrogen-rich layers between the stacked polysilicon layers, thus resulting in effective retardation of dopant diffusion. It was observed that the dopants in stacked films were piled-up at the interface. TEM image also showed clear distinction of stacked layers, their plane grain size and grain mismatch at interface layers. Therefore, the number of stacked polysilicon layers with different crystalline structures, interface position and crystal phase can be easily controlled to improve the device performance and reliability without any negative effects in nano-scale CMOSFETs.

Synthesis and Optical Property of GaN Powder Using an Ultrasonic Spray Pyrolysis Process and Subsequent Nitridation Treatment (초음파 분무 열분해 공정과 질화처리를 이용한 GaN 분말의 합성과 광학적 성질)

  • Ji, Myeong-Jun;Yoo, Jae-Hyun;Lee, Young-In
    • Journal of Powder Materials
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    • v.25 no.6
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    • pp.482-486
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    • 2018
  • Despite numerous advances in the preparation and use of GaN, and many leading-edge applications in lighting technologies, the preparation of high-quality GaN powder remains a challenge. Ammonolytic preparations of polycrystalline GaN have been studied using various precursors, but all were time-consuming and required high temperatures. In this study, an efficient and low-temperature method to synthesize high-purity hexagonal GaN powder is developed using sub-micron $Ga_2O_3$ powder as a starting material. The sub-micron $Ga_2O_3$ powder was prepared by an ultrasonic spray pyrolysis process. The GaN powder is synthesized from the sub-micron $Ga_2O_3$ powder through a nitridation treatment in an $NH_3$ flow at $800^{\circ}C$. The characteristics of the synthesized powder are systematically examined by X-ray diffraction, scanning and transmission electron microscopy, and UV-vis spectrophotometer.

Fabrication of Silicon Nitride Ceramics Using Semiconductor-Waste-Si Sludge (반도체 폐 Si 슬러지를 이용한 질화규소세라믹의 제조)

  • Lee, Byong-Taek;Yoo, Jung-Ho;Kim, Hai-Doo
    • Korean Journal of Materials Research
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    • v.9 no.12
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    • pp.1170-1175
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    • 1999
  • The microstructures and mechanical properties of $Si_3N_4$ ceramics produced by nitridation and post-sintering using semiconductor-waste-Si sludge were investigated. Lots of microcracks were observed in the waste-Si powders which contained some amounts of amorphous $SiO_2$. The nitridation rate of waste-Si compacts showed lower value than that of commercial Si powder compacts. The nitridation rate was increased with increasing nitridation temperature and then the percent of nitridation at 1470$^{\circ}C$ showed 98%. The phases of $Si_3N_4$ in the reaction-bonded bodies were mixed with ${\alpha}$ and ${\beta}$-type, and small amounts of $Si_2N_2O$ phase while those after post-sintering were ${\beta}$-$Si_3N_4$ and ${\alpha}$-Sialon. The sample post-sintered at 1950$^{\circ}C$ showed the fracture toughness of 5.6 $^MPa{\cdot}m^{1/2}$ and the fracture strength of 497 MPa which were lower than those of sintered body using commercial Si powder possibly due to the formation of ${\alpha}$-Sialon phase.

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Luminescent Properties of Europium-Doped Lanthanum Silicon Nitride Phosphor

  • Lences, Zoltan;Hrabalova, Monika;Czimerova, Adriana;Sajgalik, Pavol;Zhou, You;Hirao, Kiyoshi
    • Journal of the Korean Ceramic Society
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    • v.49 no.4
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    • pp.325-327
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    • 2012
  • Europium-doped $LaSi_3N_5$ phosphor was synthesized from LaSi/Si/$Si_3N_4/Eu_2O_3$ mixture by nitridation at $1390^{\circ}C$ and additional annealing at $1650^{\circ}C$ for 4 h. The phosphor shows emissions in the green light region with a maximum at 560 nm. With increasing europium content in the general formula $La_{1-z}Eu_zSi_3N_{5-z}O_{1.5z}$ from z = 0.01 to 0.06 there was a maximum emission for z = 0.04 followed by concentration quenching for the highest europium content (z = 0.06).

A Study on the Nitridation of $Si-Si_3N_4$ Compacts ($Si-Si_3N_4$ 성형체의 질화반응에 관한연구)

  • 이전국;김종희
    • Journal of the Korean Ceramic Society
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    • v.22 no.1
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    • pp.53-59
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    • 1985
  • Experiments related to nitriding silicon with addition of $Si_3N_4$ have provided information on the effects of such inclusion on the phase relationships of Reaction Bonded Silicon Nitride. In the current work specimens containing 0-25wt% Si3N4 which have 55.5wt% $\alpha$ 4.5wt% $eta$, 40wt% amorphous phase were nitrided for 7-20 hours at 1300-135$0^{\circ}C$ The evaluation of nitridation was per-formed by means of $\alpha$-and $\beta$-phase contents determination in nitrided specimens, In order to observe nitrided region between silicon and silicon nitride scanning electron microscopy was used to study reacted region between silicon and silicon nitride particle. For this purpose semiconductor-grade silicon wafer single crystal was used as a silicon source. The incorporation of small amount of $Si_3N_4$ powder is contributed to enhancing the rate of formation of $\alpha$-phase.

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Synthesis of AlN Powder from Al2(SO4)3.18H2O: I. Precipitation Method (Al2(SO4)3.18H2O로부터 AlN 분말의 합성: I. 침전법)

  • 이홍림;송태호
    • Journal of the Korean Ceramic Society
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    • v.28 no.6
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    • pp.465-470
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    • 1991
  • AlN powder was synthesized by carbothermal reduction and nitridation of aluminum hydroxides precipitated in 5∼11 pH range from Al2(SO4)3$.$18H2O aqueous solution. Nitridation reactivity of hydroxide, which depends on precipitation pH, reaction temperature and time, was examined by XRD analysis at 1200∼1350$^{\circ}C$ and compared with that of commercial ${\alpha}$-Al2O3. Hydroxides obtained at higher pH could be more easily nitridated and, considering DTA/TG and BET results, the reason seems to be specific surface area difference of reactants depending on the content of decomposed structural water and the transition rate from transition-Al2O3 to ${\alpha}$-Al2O3.

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