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用分子束外延设备(MBE)在GaAs(100)衬底上生长了InSb型界面的AlSb/InAs超晶格,界面生长过程中采用了As保护下不同的中断时间.运用掠入射X射线反射技术(GIXRR)对样品进行了测量,并对测量结果进行了模拟和分析,发现As保护下生长中断20 s能获得最平整的AlSb/InAs界面.结合分析显微镜下观察到的样品形貌,过短的界面中断时间会导致界面富In并形成In点,而过长的中断时间会导致AlAs型界面的形成,两者都使界面变得粗糙.另外,还讨论了生长中断在分子束外延生长中的应用.
关键词:
分子束外延
生长中断
超晶格
掠入射X射线反射 相似文献
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Coulomb blockade oscillations of Si single-electron transistors, which are fabricated completely by the conventional photolithography technique, have been investigated. Most of the single-electron transistors clearly show Coulomb blockade oscillations and these oscillations can be periodic by applying negative voltages to the in-plane gates. A shift of the peak positions is observed at high temperatures. It is also found that the fluctuation of the peak spacing cannot be neglected. 相似文献
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Single electron transistors with wire channels are fabricated by a nanoelectrode-pair technique. Their characteristics strongly depend on the channel widths and the voltages on the in-plane gates. A few dips in the Coulomb blockade oscillations were observed at the less positive gate voltages for a device with a 70nm-wide wire due to Coulomb blockade between the coupled dots. By applying negative voltages to the in-plane gates, the oscillations became periodic, which indicated the formation of a single dot in the conducting channel. These gates facilitate fabricating single-electron transistors with single dot structures, which have potential applications on its integration. 相似文献
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ZnO nanostructures with different morphologies were fabricated by changing the partial oxygen pressure. The structures, morphologies and optical properties of ZnO nanostructures were investigated by x-ray diffraction, field emission scanning electron microscopy and photoluminescence (PL) spectra at room temperature. All the samples show preferred orientation along the c-axis. The oxygen partial pressure and the annealing atmosphere have important effect on the PL property of ZnO nanostructures. The high oxygen partial pressure during growth of samples and high-temperature annealing of the ZnO samples in oxygen can increase oxygen vacancies and can especially increase antisite oxygen (OZn) defects, which degraded the near band-edge emission. However, the annealing in 1-12 can significantly modify the NBE emission. 相似文献
25.
Properties of InGaP/GaAs Grown by Solid-Source Molecular Beam Epitaxy with a GaP Decomposition Source
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Lattice-matched InGaP on GaAs (001) was successfully grown by solid-source molecular beam epitaxy witha GaP decomposition source. A 0.5-μm-thick InGaP epilayer shows photoluminescence peak energy as large as 1.991eV at 15K, the full width at half maximum as small as 9.4meV and x-ray diffraction rocking curve linewidth as narrow as 25 arcsec. The electron mobilities of undoped and Si-doped InGaP layers obtained by Hall measurements are comparable to similar InGaP/GaAs heterojunction grown by solid-source molecular beamepitaxy with other sources or other growth techniques. The results reveal that the InGaP/GaAs heterojunction grown bY the present growth way have great potential applications for semiconductor devices. 相似文献
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Growth of Highly Conductive n-Type Al0.7Ga0.3N Film by Using AlN Buffer with Periodical Variation of Ⅴ/Ⅲ Ratio
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High quality and highly conductive n-type Al0.7Ga0.3N films are obtained by using AlN multi-step layers (MSL) with periodical variation of Ⅴ/Ⅲ ratios by low-pressure metalorganic chemical vapour deposition (LP-MOCVD). The full-width at half-maximum (FWHM) of (0002) and (1015) rocking curves of the Si-doped Al0.7Ga0.3N layer are 519 and 625 arcsec, respectively, Room temperature (RT) Hall measurement shows a free electron concentration of 2.9 × 10^19 cm^-3, and mobility of 17.8cm^2V^-1s^-1, corresponding to a resistivity of 0.0121 Ω cm. High conductivity of the Si-doped AlGaN film with such high Al mole fraction is mainly contributed by a remarkable reduction of threading dislocations (TDs) in AlGaN layer. The TD reducing mechanism in AlN MSL growth with periodical variation of Ⅴ/Ⅲ ratio is discussed in detail. 相似文献
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Electroluminescent characteristics of n-ZnO/p-GaN heterojunctions under forward and reverse biases are studied. Emissions at 389nm and 57Ohm are observed under forward bias. An unusual emission at 390ram appears under reverse bias, and is attributed to the recombination in the p-GaN side of the heterojunction. The yellow emission peaked at 57Ohm is suppressed under reverse bias. The light intensity exponentially depends on the reverse current. The emission under reverse bias is correlated to tunnelling carrier transport in the heterostructure. Our results also support that the well-known yellow band of GaN comes from the transitions between some near-conduction-band-edge states and deep localized acceptor states. 相似文献
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分子束外延材料从基础研究到产业化 总被引:1,自引:0,他引:1
文章计概述了分子束外延技术和材料从实验室走向产业化的成功之路,为读者提供了一个了解高技术发展的全过程:由物理学家从理论上提出人工超晶格量子阱材料;再由器件物理学家制备出若干具有重要应用价值的器件与电路,如微波毫米波高电子迁移率晶体管及电路、量子阱激光器,从而促进了分子束外延技术的发展与完善。移动通信、移动互联肉、地面宽带无结通信、汽车防碰撞雷达、高效太阳能电池等对分子束外延材料的需求为其产业化带来 相似文献