共查询到19条相似文献,搜索用时 734 毫秒
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利用全固态分子束外延(MBE)方法在Ge(100)衬底上异质外延GaAs薄膜,并通过高能电子衍射(RHEED)、高分辨X射线衍射(XRD),原子力显微镜等手段研究了不同生长参数对外延层的影响.RHEED显示在较高的生长温度或较低的生长速率下,低温GaAs成核层呈现层状生长模式.同时降低生长温度和生长速率会使GaAs薄膜的XRD摇摆曲线半高宽(FWHM)减小,并降低外延层表面的粗糙度,这主要是由于衬底和外延薄膜之间的晶格失配度减小的结果. 相似文献
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使用分子束外延方法,采用In束流保护下的调制中断生长技术,在(0001)蓝宝石衬底上生长GaN薄膜.利用反射式高能电子衍射(RHEED)对生长进行实时监控,并用扫描电子显微镜(SEM)、原子力显微镜(AFM)和X射线衍射(XRD)法对GaN外延薄膜的表面形貌和晶体质量进行分析.实验结果表明:采用该技术生长的Ga极性GaN外延薄膜中的晶体表面残留Ga滴密度大大降低,GaN外延薄膜的表面形貌得到改善,其均方根粗糙度(RMS)由3nm降低为0.6nm,同时XRD双晶摇摆曲线测试的结果表明,GaN外延层的晶格质量也得到改善. 相似文献
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使用分子束外延方法,采用In束流保护下的调制中断生长技术,在(0001)蓝宝石衬底上生长GaN薄膜.利用反射式高能电子衍射(RHEED)对生长进行实时监控,并用扫描电子显微镜(SEM)、原子力显微镜(AFM)和X射线衍射(XRD)法对GaN外延薄膜的表面形貌和晶体质量进行分析.实验结果表明:采用该技术生长的Ga极性GaN外延薄膜中的晶体表面残留Ga滴密度大大降低,GaN外延薄膜的表面形貌得到改善,其均方根粗糙度(RMS)由3nm降低为0.6nm,同时XRD双晶摇摆曲线测试的结果表明,GaN外延层的晶格质量也得到改善. 相似文献
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我们用原位直流磁控溅射的方法,在(100)SrTiO_3,(110)SrTiO_3,(100)LaAlO_3和(100)Zr(Y)O_2衬底上制备了高质量外延生长的GdBa_2Cu_3O_(7-s)高温超导薄膜,重复性非常好.在这四种衬底上生长的超导薄膜最高零电阻转变温度 Tco分别为 93.2、93.1、92.6和 92.5K,77K零场下的临界电流密度分别为 3.0 ×10~6,3 × 10~5,3.6 ×10~6和 1.4 × 10~6A/cm~2.我们用扫描电镜(SEM),透射电镜(TEM),反射高能电子衍射(RHEED)和不同几何结构的X射线衍射研究了薄膜的结构,这些研究结果证明薄膜系外延生长的. 相似文献
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为提升大面阵II类超晶格红外探测器的性能、产量和材料质量,对3 in长波InAs/GaSb II类超晶格分子束外延(Molecular Beam Epitaxy, MBE)生长工艺优化进行了研究。结合反射式高能电子衍射(Reflection High-Energy Electron Diffraction, RHEED)条纹研究了不同的去氧化层温度和生长温度对3 in外延片质量的影响。使用光学显微镜、原子力显微镜(Atomic Force Microscopy, AFM)、表面颗粒检测仪、白光干涉仪、高分辨X射线衍射仪(High-Resolution X-Ray Diffractometer, HRXRD)以及X射线衍射谱模拟分别对外延片的表面形貌、均匀性和晶格质量进行了表征。优化后外延片1 μm以上缺陷的密度为316 cm-2,粗糙度为0.37 nm,总厚度偏差(Total Thickness Variation, TTV)为19.6 μm,77 K下截止波长为9.98 μm。在2 in长波II类超晶格分子束外延生长工艺的基础上,研究了增大GaSb衬底尺寸后相应生长条件的变化情况。这对尺寸增大后III-V族分子束外延工艺条件的调整具有参考意义,也为锑基II类超晶格红外探测器的面阵规模、质量和产能提升奠定了基础。 相似文献
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通过分子束外延(MBE)生长技术,在GaAs(100)基片上生长出单晶In_xGa_(1-x)As薄膜,利用反射高能电子衍射仪(RHEED)实时监控薄膜生长情况。对In_xGa_(1-x)As薄膜进行了X射线衍射(XRD)测试,结果显示该薄膜为高质量薄膜,且In组分(原子数分数)为0.51。光致发光(PL)光谱测试结果表明,室温下发光峰位约为1.55μm;由于In_xGa_(1-x)As薄膜中存在压应变,光谱峰位出现蓝移。Raman光谱显示GaAs-like横向光学声子(TO)模式的峰出现了明显展宽,验证了In_xGa_(1-x)As薄膜中存在应变。 相似文献
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介绍了反射式高能电子衍射仪(RHEED)衍射原理以及半导体薄膜表面原子间距与其衍射图像间距成反比例关系。分析了采用ECR-PEMOCVD生长技术,在α-Al2O3衬底上低温外延GaN基薄膜(氮化层、缓冲层、外延层)工艺过程。通过对RHEED图像分析软件获取不同工艺过程中的外延薄膜衍射条纹间距的数据分析、计算、比较,得到薄膜表面衍射图像间距的大小,依据RHEED衍射图像与原子面间距之间的对应关系,分析薄膜表面的应变状态演变情况。分析计算结果表明生长20min氮化层、20min缓冲层的表面原子层处于压应变状态,而生长180min的AlN外延层,表面则处于完全弛豫状态。 相似文献
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用脉冲激光沉积在(001)SrRuO3,(001)SrTiO3上外延生长了c轴取向的Bi3.15Nd0.85Ti3O12(BNdT)铁电薄膜.SrRuO3底电极层厚约117 nm,BNdT薄膜厚~35nm.X射线衍射(XRD)和透射电镜(TEM)观察证实了SrRuO3层和BNdT薄膜的外延生长.通过TEM平面样品观察,在SrRuO3/BNdT界面附近看到了两种村度处于不同高度的失配位错网,位错线沿<110>走向,其柏格斯矢量沿[110]或[110]方向有分量,在[001]方向上可能没有分量.讨论了位错的形成机制. 相似文献
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本文利用高分辨电子显微术、电子能量损失谱和电子全息技术对Si基体上生长的SrTiO3(STO)和La0.9Sr0.1MnO3(LSMO)薄膜及其STO层和Si基体之间的界面结构进行了深入研究,结果表明在Si和STO层之间由于氧扩散会形成一层过渡的SiOx无序层,且随沉积条件不同界面原子无序层厚度稍有不同;选区电子衍射结果表明薄膜和基体之间的外延生长关系为[001]LSMO//[^-110]Si,[110]LSMO//[001]Si[001]STO,//[001]Si,[010]STO//[110]Si;电子能量损失谱分析表明界面无序层中Si离子的氧化态处于Si^2+和Si^0之间;电子全息结果清晰地显示了基体与薄膜之间存在明显的相位和势垒变化,负电荷聚集在界面SiOx的无序层中。 相似文献
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Bensaoula A. Malki H.A. Kwari A.M. 《Semiconductor Manufacturing, IEEE Transactions on》1998,11(3):421-431
This paper demonstrates the incorporation of a multilayer neural network in semiconductor thin film deposition processes. As a first step toward neural network-based process control, we present results from neural network pattern classification and beam analysis of reflection high energy electron diffraction RHEED images of GaAs/AlGaAs crystal surfaces during molecular beam epitaxy growth. For beam analysis, we used the neural network to detect and measure the intensity of the RHEED beam spots during the growth process and, through Fourier transformation, determined the thin film deposition rate. The neural network RHEED pattern classification and intensity analysis capability allows, powerful in situ real time monitoring of epitaxial thin film deposition processes. Our results show that a three layer network with sixteen hidden neurons and three output neurons had the highest correct classification rate with a success rate of 100% during testing and training on 13 examples 相似文献
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M. El Kazzi C. Merckling G. Delhaye L. Arzel G. Grenet E. Bergignat G. Hollinger 《Materials Science in Semiconductor Processing》2006,9(6):954
This study investigates the tensile-strained growth of LaAlO3 on SrTiO3(0 0 1) substrate by molecular beam epitaxy (MBE). Growth was controlled in situ by reflection high energy electron diffraction (RHEED). The characterization was carried out ex situ by photoemission and atomic force microscopy (AFM). Photoelectron spectroscopy (XPS) reveals the development of a TiOx-rich interface. Photoelectron diffraction (XPD) confirms that a 1.2-nm-thick pseudomorphic LaAlO3 film has been grown on SrTiO3(0 0 1) substrate with a perpendicular lattice parameter of 0.372±0.02 nm. 相似文献
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D. Schikora Th. Widmer C. Prott K. Lischka G. Machel P. Schfer S. Luther M. Von Ortenberg 《Solid-state electronics》1996,40(1-8):63-67
Single quantum wells (SQW) and superlattices of mercury-iron selenide (HgSe:Fe) have been grown by molecular beam epitaxy (MBE) and characterized by in-situ high-energy electron diffraction (RHEED) and magneto spectroscopy investigations. The influence of the structural parameters of the ZnTe buffer layer on the properties of the HgSe:Fe microstructures has been investigated by RHEED-mosaic structure analysis. The onset of strain relaxation at the critical thickness has been determined by intensity-profile analysis of different reflexes in the RHEED pattern. These results are compared with high resolution X-ray measurements (HRXRD) of the lattice relaxation of the HgSe layer. Different types of HgSe:Fe/HgSe quantum well structures and superlattices have been characterized by magneto transport investigations. The clear resolved plateau structure of the Hall voltage (Quantum Hall Effect) indicates the existence of a Q2D electron gas in the layers which is also corroborated by the cosine dependence of the peak shift of the Shubnikov de Haas (SdH)-oscillations in tilted magnetic fields. 相似文献
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采用激光分子束外延方法(L-MBE),在GaAs(001)衬底上同质外延GaAs薄膜。利用反射式高能电子衍射(RHEED)研究了材料沉积过程中的各级条纹及其强度的变化,进而得出GaAs薄膜外延生长的适宜激光能量和沉积温度分别为500 mJ和570℃。RHEED强度随时间的变化曲线表明,GaAs为良好的层状外延生长模式,并随着沉积时间延长,层状生长模式逐渐向岛状模式转变。实验研究还表明层状生长的GaAs薄膜经表面弛豫后,可以得到更好的平整表面,并出现GaAs(001)-(2×4)的表面重构。原位X射线光电子能谱仪(XPS)研究表明沿(001)面外延的GaAs薄膜表面Ga∶As化学计量比约为52∶48,出现Ga的聚集。 相似文献
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用RHEED方法分析半导体薄膜特性 总被引:1,自引:0,他引:1
在讨论RHEED原理的基础上,介绍了组建的RHEED和其附属的真空系统,并用此装置得到了Si薄膜的RHEED衍射花样。本文还对实验条件和实验结果进行了简单的分析和介绍。 相似文献
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M. A. Folkard G. Shen V. Kumar T. A. Steele D. Rees I. K. Varga D. Carr K. Fueloep B. A. Johnson P. J. Orders R. H. Hartley H. Buskes M. Gal 《Journal of Electronic Materials》1993,22(8):1097-1102
Phase modulated ellipsometric data recorded during molecular beam epitaxial growth of CdTe/HgTe and CdTe/ZnTe superlattices
on (100) and (211)B oriented Cd0.96Zn0.04Te and GaAs substrates are presented. The measurements provide a continuous monitor of the growth process, thickness, growth
rate, compositional data, and evidence of interdiffusion in CdTe/HgTe superlattices at elevated temperatures. The thickness
measurements are independent of growth kinetics and surface orientation and agree well with those obtained from x-ray diffraction
and reflection high energy electron diffraction. Ellipsometry shows that the incorporation of Hg in CdTe is significantly
higher on (100) oriented surfaces than on (211)B oriented surfaces. Fine structure in the data from CdTe/ZnTe superlattices
may be associated with a surface reconstruction during deposition of each CdTe layer. The experimental results for CdTe/HgTe
superlattices compare well with results of thin film multi-layer calculations. The general applicability of ellipsometry as
an in-situ analytical technique for epitaxial growth of a range of semiconductor superlattices is discussed. 相似文献