• Title/Summary/Keyword: Plasma-assisted molecular-beam epitaxy

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Optical Emission Spectra of Oxygen Plasma Produced by Radio-Frequency Plasma (RF 플라즈마에 의해 생성된 산소 플라즈마의 발광 스펙트럼)

  • Kim, Do-Yeob;Kim, Min-Su;Kim, Tae-Hoon;Kim, Ghun-Sik;Choi, Hyun-Young;Cho, Min-Young;Jeon, Su-Min;Park, Sung-Dong;Kim, Jin-Ha;Kim, Eun-Do;Hwang, Do-Weon;Lee, Jae-Young
    • Journal of the Korean Vacuum Society
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    • v.18 no.2
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    • pp.102-107
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    • 2009

  • We investigated optical emission of oxygen plasma discharged by 13.56 MHz radio frequency (rf) by using optical emission spectroscopy (OES). Experimental measurement is done at a range of oxygen flow rate of 1$\sim$20 seem, rf power of 25$\sim$250 W, and orifice 3 and 5 mm in diameter. When oxygen plasma was generated, typical emission spectra for oxygen plasma were observed regardless of diameter of orifice. Strong atomic emission lines are observe at 776.8 an 843.9 nm, corresponding to the $3p^{5}P-3s^{5}S^{0}$ and $3p^{3}P-3s^{3}S^{0}$ transitions, respectively. The emission intensity of line at 776.8 and 843.9 nm increased with increasing the oxygen flow rate and rf power. The increasing rate of emission intensity of 776.8 nm line was larger than that of 843.9 nm line. When the diameter of orifice was 3 mm, the oxygen plasma was more stably generated than orifice 5 mm in diameter.

  • https://doi.org/10.5757/JKVS.2009.18.2.102 인용 PDF KSCI

Effects of AlN Ratio on Microstructure of AlN Films Grown by PAMBE (PAMBE를 이용하여 성장된 AlN 박막의 미세구조에 미치는 Al/N 비율 영향)

  • 홍성의;한기평;백문철;조경익;윤순길
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.12
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    • pp.972-978
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    • 2001

  • Some effects of Al/N ratio on microstructure of AlN films grown on Si(111) substrates by PAMBE were investigated. Al/N ratio was controlled by rf power of N$_2$ plasma source system. Al excess or N excess conditions were obtained below or above 350 W rf power, respectively. Surface roughness and morphology of AlN film grown at Al/N=1.0 showed the best result. Under Al excess condition, it was suggested that excess Al atoms which did not contribute to the growth of AlN film prevent the normal crystal growth and make abnormal growth of some columns. However, under N excess condition, it was explained that some of the excess active N source turned into gas state and then desorbed out from substrate.

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Formation of a thin nitrided GaAs layer

  • Park, Y.J.;Kim, S.I.;Kim, E.K.;Han, I.K.;Min, S.K.;O'Keeffe, P.;Mutoh, H.;Hirose, S.;Hara, K.;Munekata, H.;Kukimoto, H.
    • Proceedings of the Korean Vacuum Society Conference
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    • 1996.06a
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    • pp.40-41
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    • 1996

  • Nitridation technique has been receiving much attention for the formation of a thin nitrided buffer layer on which high quality nitride films can be formedl. Particularly, gallium nitride (GaN) has been considered as a promising material for blue-and ultraviolet-emitting devices. It can also be used for in situ formed and stable passivation layers for selective growth of $GaAs_2$. In this work, formation of a thin nitrided layer is investigated. Nitrogen electron cyclotron resonance(ECR)-plasma is employed for the formation of thin nitrided layer. The plasma source used in this work is a compact ECR plasma gun3 which is specifically designed to enhance control, and to provide in-situ monitoring of plasma parameters during plasma-assisted processing. Microwave power of 100-200 W was used to excite the plasma which was emitted from an orifice of 25 rnm in diameter. The substrate were positioned 15 em away from the orifice of plasma source. Prior to nitridation is performed, the surface of n-type (001)GaAs was exposed to hydrogen plasma for 20 min at $300{\;}^{\circ}C$ in order to eliminate a native oxide formed on GaAs surface. Change from ring to streak in RHEED pattern can be obtained through the irradiation of hydrogen plasma, indicating a clean surface. Nitridation was carried out for 5-40 min at $RT-600{\;}^{\circ}C$ in a ECR plasma-assisted molecular beam epitaxy system. Typical chamber pressure was $7.5{\times}lO^{-4}$ Torr during the nitridations at $N_2$ flow rate of 10 seem.(omitted)mitted)

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Si과 Mg Doping된 GaN 나노막대의 모양과 PL 특성 변화

  • Kim, Gyeong-Jin;Lee, Sang-Tae;Park, Byeong-Gwon;Choe, Hyo-Seok;Kim, Mun-Deok;Kim, Song-Gang;O, Jae-Eung
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.459-459
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    • 2013

  • Si (111) 기판 위에 plasma assisted molecular beam epitaxy 법으로 Si과 Mg doping된 GaN 나노막대를 각 각 성장하고 나노막대의 모양과 광학적 특성을 조사하였다. Si이 doping된 GaN 나노막대는 biaxial m-plane 방향의 변화로 별 모양을 갖는 것을 관찰하였고 Mg doping된 GaN 나노막대의 지름은 줄어드는 것을 scanning electron microscopy로 확인하였다. 본 연구에서는 이러한 변화의 원인을 stress 때문으로 보고 x-ray diffraction과 raman scattering 측정을 통하여 구조적 변화를 조사하였다. 또한, stress에 의한 GaN 나노막대의광학적 특성 변화를 photoluminescence을 통하여 조사하였다. Doping한 GaN 나노막대의 특성조사를 통해 GaN 나노막대 성장 시 발생되는 stress의 영향을 이해하는데 중요한 정보를 제공할 것이다.

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