• Title/Summary/Keyword: superlattice

Search Result 175, Processing Time 0.027 seconds

X-ray diffraction analysis of ZnS/ZnSe superlattices prepared by hot wall epitaxy (열벽적층성장에 의하여 제작된 ZnS/ZnSe 초격자의 X-선 회절분석)

  • Yong Dae Choi;A. Ishida;Fujiyasu, H.
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.6 no.3
    • /
    • pp.377-385
    • /
    • 1996
  • ZnS/ZnSe superlattices were prepared on GaAs (100) substrates by hot wall epitaxy, an the structures were analyzed using x-ray diffraction. It is shown that the x-ray diffraction of the strained superlattice gives very useful information about the thickness of each layer, strain, interdiffusion, and the fluctuation of the superlattice period. Interdiffusion length of the S and Se is estimated to be less than $2\;{\AA}$.

  • PDF

Electrical and Photoluminescence Characteristics of Nanocrystalline Silicon-Oxygen Superlattice for Silicon on Insulator Application

  • Seo, Yong-Jin
    • KIEE International Transactions on Electrophysics and Applications
    • /
    • v.2C no.5
    • /
    • pp.258-261
    • /
    • 2002
  • Electrical forming dependent current-voltage (I-V) and numerically derived differential conductance(dI/dV) characteristics have been presented in the multi-layer nano-crystalline silicon/oxygen (no-Si/O) superlattice. Distinct staircase-like features, indicating the presence of resonant tunnel barriers, are clearly observed in the dc I-V characteristics. Also, all samples showed a continuous change in current and zero conductivity around OV corresponding to the Coulomb blockade in the calculated dI/dV-V curve. Also, Ra-man scattering measurement showed the presence of a nano-crystalline Si structure. This result becomes a step in the right direction for the fabrication of silicon-based optoelectronic and quantum devices as well as for the replacement of silicon-on-insulator (SOI) in high speed and low power silicon MOSFET devices of the future.

The study of GaN-based semiconductors with low-defect density by microstructural characterization (미세구조 분석을 이용한 저밀도 결함을 가진 GaN계 반도체 연구)

  • Cho, Hyung-Koun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.07a
    • /
    • pp.424-427
    • /
    • 2003
  • We have investigated the microstructural analysis of epitaxial lateral overgrowth (ELO), pendeoepitaxy (PE), and superlattice structures used as technology for the reduction of structural defects like dislocation in nitride semiconductors using transmission electron microscopy. We confirmed that the regrowth process such as ELO and PE is very effective technique on the reduction of threading dislocation (less than $10^6/cm^2$) in the specific area. However, to decrease the defect density in the whole nitride films and the suppress the generation of defect by regrowth, we should find the optimized conditions. Besides, the process using double PE and AlGaN/GaN superlattice structure showed no effect on the defect reduction up to now.

  • PDF

The Stability of Hydrogenated Amorphous Silicon by Hydrogen Radical Annealing (수소기처리에 의한 수소화된 비정질규소의 안정성에 관한 연구)

  • 이재희;이원식
    • Journal of the Korean Vacuum Society
    • /
    • v.5 no.1
    • /
    • pp.73-76
    • /
    • 1996
  • We have prepared hydrogenated amophous silicon (a-si : H) films with superlattice structure by hydrogen radical anneling(HRA) technique. We have studied the preparation of a-Si :H films by HRA and the optical & electronic characteristics. Optical band gap and the hydrogen contents in the a Si : H film is decreased as HRA time increased. We first report a -Si : H film prepared by periodicdeposition of a-Si : H layer and HRA have the superlattice structure using TEM . After 1 hour light soaking on the a-Si :H film prepared by HRA, there are no difference in the temperatre dependence of dark conductivity and the conductivity activation energy. An excellent stability for light in a-Si :H films by HRA can be explained using the long-range structural relaxation of the amorphous network and the propertiesof light -induced defects(LID) proposed by Fritzsche.

  • PDF