• 제목/요약/키워드: Epitaxial

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Current-Voltage and Conductance Characteristics of Silicon-based Quantum Electron Device (실리콘 양자전자소자의 전류-전압 및 컨덕턴스 특성)

  • Seo, Yong-Jin
    • Journal of IKEEE
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    • v.23 no.3
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    • pp.811-816
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    • 2019
  • The silicon-adsorbed oxygen(Si-O) superlattice grown by ultra high vacuum-chemical vapor deposition(UHV-CVD) was introduced as an epitaxial barrier for silicon quantum electron devices. The current-voltage (I-V) measurement results show the stable and good insulating behavior with high breakdown voltage. It is apparent that the Si-O superlattice can serve as an epitaxially grown insulating layer as possible replacement of silicon-on-insulator(SOI). This thick barrier may be useful as an epitaxial insulating gate for field effect transistors(FETs). The rationale is that it should be possible to fabricate a FET on top of another FET, moving one step closer to the ultimate goal of future silicon-based three-dimensional integrated circuit(3DIC).

Thermal-annealing behavior of in-core neutron-irradiated epitaxial 4H-SiC

  • Junesic Park ;Byung-Gun Park;Gwang-Min Sun
    • Nuclear Engineering and Technology
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    • v.55 no.1
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    • pp.209-214
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    • 2023
  • The effect of thermal annealing on defect recovery of in-core neutron-irradiated 4H-SiC was investigated. Au/SiC Schottky diodes were manufactured using a 4H-SiC epitaxial wafer that was neutron-irradiated at the HANARO research reactor. The electrical characteristics of their epitaxial layers were analyzed under various conditions, including different neutron fluences (1.3 × 1017 and 2.7 × 1017 neutrons/cm2) and annealing times (up to 2 h at 1700 ℃). Capacity-voltage measurements showed high carrier compensation in the neutron-irradiated samples and a recovery tendency that increased with annealing time. The carrier density could be recovered up to 77% of the bare sample. Deep-level-transient spectroscopy revealed intrinsic defects of 4H-SiC with energy levels 0.47 and 0.68 eV below the conduction-band edge, which were significantly increased by in-core neutron irradiation. A previously unknown defect with a high electron-capture cross-section was discovered at 0.36 eV below the conduction-band edge. All defect concentrations decreased with 1700 ℃ annealing; the decrease was faster when the defect level was shallow.

Phase Transformation in Epitaxial Growth of Galium Nitride by HVPE Process (HVPE법에 의한 질화갈륨 단결정막 성장시 상전이에 관한 연구)

  • Rakova, E.V.;Kuznetsov, A.V.;Kim, Hyang Sook;Lee, Sun Sook;Hwang, Jin Soo;Chong, Paul Joe
    • Korean Journal of Crystallography
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    • v.6 no.1
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    • pp.49-55
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    • 1995
  • The oriented islands of cubic galium nitride are grown on the (0001) surface of hexagonal GaN epitaxial films by halide vapour phase epitaxial process. The mutual orientation of cubic β-GaN and hexagonal α-GaN phase was observed as : [110](111) β-GaN//[1120](0001) α-GaN. Trigonally faced islands of β-GaN occupy the twined positions in relation to (111) plane in parallel to the film surface. The band gap value for β-GaN determuned from photo and local catchodoluminescent measurments is estimated to be 3.18±0.30eV at room temperature.

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Multi-step growth of a-plane GaN epitaxial layer on r-plane sapphire substrate by HVPE method (HVPE를 이용하여 r-plane 사파이어 위에 multi-step으로 성장시킨 a-plane GaN 에피층의 특성 연구)

  • Lee, Won-Jun;Park, Mi-Seon;Jang, Yeon-Suk;Lee, Won-Jae;Ha, Ju-Hyung;Choi, Young-Jun;Lee, Hae-Yong;Kim, Hong-Seung
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.26 no.3
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    • pp.89-94
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    • 2016
  • In this study, the crystalline property of a-plane GaN epitaxial layer grown on r-plane sapphire by a HVPE method has been investigated according to the V/III ratio and the growth time of multi-step growth. Furthermore, these results were compared with the previous result obtained from the single-step growth of a-plane GaN on r-plane sapphire substrate. In the multi-step growth for a-plane GaN epitaxial layer on r-plane sapphire, the FWHM values of rocking curve in GaN epitaxial layer were decreased as the HCl source flow rate and the growth time were increased. The void formed in epitaxial layer was continuously decreased as the growth time in first step and second step using a higher HCl flow rate was increased. As a result, the GaN layer obtained with the longest growth time on the first step and second step exhibited the lowest FWHM values of 584 arcsec and the smallest dependence of azimuth angle.