共查询到20条相似文献,搜索用时 46 毫秒
1.
面向对注氢硅片中微结构的影响 总被引:1,自引:1,他引:0
把不同面向的注氢硅片制成横截面样品,在高分辨率透射电子显微镜下进行观察,发现衬底面向对其中的微结构有明显的影响.首先表现为衬底中主要出现平行于正表面的氢致片状缺陷,即(10 0 )衬底中,主要出现平行于正表面的{ 10 0 }片状缺陷,而(111)衬底中出现的主要是平行于正表面的{ 111}片状缺陷.其原因是注入引起垂直正表面的张应变.另外,面向的影响还表现为,(10 0 )衬底中出现的{ 113}缺陷在(111)衬底中不出现.在(111)衬底中出现的晶格紊乱团和空洞在(10 0 )衬底中不出现.从而推测,{ 111}片状缺陷的形成不发射自间隙原子,而(10 0 )片状缺陷的形成将发射自 相似文献
2.
J. Gerster J. M. Schneider C. Ehret W. Limmer R. Sauer H. Heinecke 《Microelectronics Journal》1997,28(8-10):985-992
Local carrier transport properties of Si-doped GaAs layers on ridge structures exhibiting (111)A and (111)B sidewalls are investigated. The layers were grown by molecular beam epitaxy at different substrate temperatures and As/Ga flux ratios. Using spatially resolved Raman spectroscopy we determine the type and density of free charge carriers (≥ 5 × 1017 cm−3) in the grown layers on the different index facets from an analysis of the coupled plasmon-longitudinal optical-phonon mode which was calibrated against Hall standards. We demonstrate that on the (100) and (111)B facets the regrown layers are n-type and on the (111)A facets p- or n-type depending on the growth conditions. Line scans of the carrier density show that the (100)/(111)A/(100) facet transition forms a graded lateral n-p-n junction. Spatially resolved photoluminescence measurements confirm our findings. 相似文献
3.
4.
Xinbo Yang K. Fujiwara K. Maeda J. Nozawa H. Koizumi S. Uda 《Progress in Photovoltaics: Research and Applications》2014,22(5):574-580
The crystal growth shape (CGS) and equilibrium crystal shape (ECS) of silicon in Si melt are observed using in situ observation. Fully faceted silicon CGSs, which are dominated by the {111} facets, are observed from the {112} and {110} orientation. Silicon CGS in three‐dimensional in Si melt is octahedral in shape, bounded by {111} facets. Silicon ECSs in the melt are obtained by the relaxation from the CGSs and exhibit the {111} facets separated by curved interface. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
5.
J. Groenen R. Carles E. Chimenti G. AttoIini C. Pelosi P. P. Lottici 《Microelectronics Journal》1997,28(8-10):939-945
Three-dimensional micrometer-sized GaAs islands, with pyramidal shapes, have been grown by metal organic vapour phase epitaxy on (111)B InAs. The local strain profile in a single isolated pyramid is deduced from spatially resolved Raman and photoluminescence measurements. High residual tensile strains are found in the GaAs layer surrounding the pyramid. The strain in the pyramid is progressively relaxed from the bottom to the top (nearly strain-free). Furthermore, the Raman selection rules are correlated to the [111] substrate orientation and the high index pyramid facets. 相似文献
6.
K. M. Dzurko S. G. Hummell E. P. Menu P. D. Dapkus 《Journal of Electronic Materials》1990,19(12):1367-1372
We investigate the MOCVD growth characteristics of AlGaAs on nonplanar {111}A and {111}B substrates. Growth over features
etched into the {111} substrates is found to be highly anisotropic and asymmetric. The ratio of growth rates on adjacent facets
is strongly dependent on the depth of the etched feature during growth, and is strikingly different between AlGaAs and GaAs
layers. These observations suggest a large difference in the surface chemistry of Al and Ga species under these growth conditions
and indicate that the column III element determines the relative growth rates of different facets during nonplanar growth.
The results also provide strong evidence that lateral gas phase diffusion of reactants can be perhaps more significant than
surface migration as a mechanism determining the incorporation sites of column III elements. Growth characteristics on nonplanar
{111} substrates are markedly different than those observed for nonplanar growth on {100} substrates, creating a new set of
design tools for the single step growth of guided wave devices such as lasers, modulators and waveguides. 相似文献
7.
Zero-net strained multilayers alternating GalnP and InAsP with lattice mismatches with InP of −1% and 1% respectively have been grown by Metallo-Organic Vapour Phase Epitaxy and examined by Transmission Electron Microscopy. Different substrate orientations were used, inducing different growth morphologies. On (001) and (113)B substrates, the GalnP and InAsP layers were laterally modulated, forming vertical stripes parallel to the [1
0] and [3
] directions respectively. This could be related to the surface reconstruction (group V element dimerisation), which favours islands built with facets of A type (gallium steps) rather than with facets of B type (arsenic steps). On a (110) vicinal substrate (misorientation of 3° towards (111)B), a step bunching phenomenon was observed. 相似文献
8.
The surface growth kinetics of CdTe and HgTe have been investigated during molecular and metalorganic molecular beam epitaxy.
The surface growth kinetics was studied through in-situ measurements of the growth rate as a function of flux ratio and substrate
temperature on the (001), (111)B, and (211)B CdTe surface orientations. For the (001) and (111)B CdTe growth kinetics, the
existence of low binding energy surface precursor sites was proposed for both molecular and atomic growth species before lattice
incorporation. Intensity oscillations were observed during HgTe growth on misoriented (111)B surfaces and during CdTe growth
on the (211)B orientation. The (211)B surface reconstructions displayed both vicinal and singular surface characteristics,
depending on the growth flux ratio. 相似文献
9.
Tuning the Au‐Free InSb Nanocrystal Morphologies Grown by Patterned Metal–Organic Chemical Vapor Deposition 下载免费PDF全文
Andrew Lin Joshua N. Shapiro Holger Eisele Diana L. Huffaker 《Advanced functional materials》2014,24(27):4311-4316
A thorough study of direct InSb nanocrystal formations on patterned InAs (111)B substrates is provided. These nanostructures are created without the use of Au catalysts or initial InAs segments. Under the growth conditions generally used for selective‐area, catalyst‐free epitaxy, a wide range of InSb nanocrystal morphologies are observed. This is because the low‐energy InSb surfaces, studied by first‐principles calculations, are the {111} facets as opposed to the {110} facets. By controlling the V/III ratio during growth, different InSb nanostructures can be achieved. Using low V/III growth conditions, In droplets start to form and InSb nucleation takes place at the droplet–semiconductor interface only, resulting in vertical, self‐catalyzed InSb nanopillars. 相似文献
10.
Semiconductors - The self-catalyzed growth of planar GaAs nanowires is analyzed using the lattice kinetic Monte Carlo model. Vapor–liquid–solid nanowire growth on (111)A and (111)B... 相似文献
11.
Yong Xia Wei Chen Peng Zhang Sisi Liu Kang Wang Xiaokun Yang Haodong Tang Linyuan Lian Jungang He Xinxing Liu Guijie Liang Manlin Tan Liang Gao Huan Liu Haisheng Song Daoli Zhang Jianbo Gao Kai Wang Xinzheng Lan Xiuwen Zhang Peter Müller‐Buschbaum Jiang Tang Jianbing Zhang 《Advanced functional materials》2020,30(22)
Trap states in colloidal quantum dot (QD) solids significantly affect the performance of QD solar cells, because they limit the open‐circuit voltage and short circuit current. The {100} facets of PbS QDs are important origins of trap states due to their weak or missing passivation. However, previous investigations focused on synthesis, ligand exchange, or passivation approaches and ignored the control of {100} facets for a given dot size. Herein, trap states are suppressed from the source via facet control of PbS QDs. The {100} facets of ≈3 nm PbS QDs are minimized by tuning the balance between the growth kinetics and thermodynamics in the synthesis. The PbS QDs synthesized at a relatively low temperature with a high oversaturation follow a kinetics‐dominated growth, producing nearly octahedral nanoparticles terminated mostly by {111} facets. In contrast, the PbS QDs synthesized at a relatively high temperature follow a thermodynamics‐dominated growth. Thus, a spherical shape is preferred, producing truncated octahedral nanoparticles with more {100} facets. Compared to PbS QDs from thermodynamics‐dominated growth, the PbS QDs with less {100} facets show fewer trap states in the QD solids, leading to a better photovoltaic device performance with a power conversion efficiency of 11.5%. 相似文献
12.
Y. Nakamura Ichiro Tanaka N. Takeuchi S. Koshiba H. Sakaki 《Journal of Electronic Materials》1998,27(11):1240-1243
We studied morphology of GaAs surfaces and the transport properties of two-dimensional electron gas (2DEG) on vicinal (111)B
planes. Multi-atomic steps (MASs) are found on the vicinal (111)B facet grown by molecular beam epitaxy, which will affect
electron transport on the facet. We also studied how the morphology of GaAs epilayers on vicinal (111)B substrates depends
on growth conditions, especially on the As4 flux. The uniformity of MASs on the substrates have been improved and smooth surfaces were obtained when the GaAs was grown
with high As4 flux, providing step periodicity of 20 nm. The channel resistance of the 2DEG perpendicular to the MASs is reduced drastically
with this smooth morphology. These findings are valuable not only for fabricating quantum devices on the (111)B facets but
also those on the vicinal (111)B substrates. 相似文献
13.
F. T. Smith P. W. Norton P. Lo Vecchio N. Hartle M. Weiler N. H. Karam S. Sivananthan Y. P. Chen 《Journal of Electronic Materials》1995,24(9):1287-1292
The growth of high quality (111)B oriented HgCdTe layers on CdZnTe/GaAs/Si and CdTe/Si substrates by Te-rich slider liquid
phase epitaxy (LPE) is reported. Although the (111) orientation is susceptible to twinning, a reproducible process yielding
twin-free layers with excellent surface morphology has been developed. The electrical properties and dislocation density in
films grown on these substrates are comparable to those measured in HgCdTe layers grown on bulk CdTe substrates using the
same LPE process. This is surprising in view of the large lattice mismatch that exists in these systems. We will report details
of both the substrate and HgCdTe growth processes that are important to obtaining these results. 相似文献
14.
E. R. Gertner A. M. Andrews L. O. Bubulac D. T. Cheung M. J. Ludowise R. A. Riedel 《Journal of Electronic Materials》1979,8(4):545-554
Reported here, for the first time, is the lattice matched growth of InAs1-xSbx on GaSb. The thermodynamic incompatibility of the system, i.e., the strong tendency for the In-As-Sb liquid to dissolve the
GaSb substrate, was solved via a novel liquid phase epitaxial growth technique. Liquid compositions for lattice matching conditions
have been determined in the 400-600°C range. Epitaxial growth has been examined for (100), (111)B and (111)A orientations.
Dislocation etch pit densities for lattice matched, and near lattice matched conditions are shown to be less than 104-cm−2 and 105-cm−4, respectively. The composition of the epitaxial layers are determined by the Gandolfi X-ray diffraction technique and compositional
homogeneity has been confirmed by SEM X-ray analysis. Some material related device properties which demonstrate the reproducibility
of the growth technique are presented. 相似文献
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We have studied the cathodoluminescence of AlxGa1-xAs/GaAs multilayers grown on ridge-type triangles by molecular beam epitaxy. The compositional variation of Al, as well as the distribution of impurity and/or defect, was revealed by variations in the cathodoluminescence spectra and images. The Al composition in an AlxGa1-xAs layer was highest in the (111)A facet and decreased in the order (100), (411)A, (111)-delta and (110) facets. On the other hand, the carbon concentration was highest in the (411)A facet and decreased in the order (111)A, (111)-delta, (100) and (110) facets. It should be noted that the (111)-delta facet has a significant effect on the redistribution of Al. Although our ridge-type triangles are rather large for the quantum structures, these data have elucidated the self-organization mechanism of the AlxGa1-xAs/GaAs system and have yielded information on the design of quantum structures. We conclude that cathodoluminescence observation is a powerful tool for studying the compositional variation or band structure of three-dimensional microscale or nanoscale construction. 相似文献
17.
使用MOCVD外延系统,采用3D-2D生长模式在圆锥图形蓝宝石衬底上生长GaN薄膜。研究发现3D-2D生长模式能够有效的减少GaN薄膜的穿透性位错,其中3D GaN层的生长条件是关键:低V/III比,低温和高生长压力。为了进一步减少TD,3D GaN层的厚度应该与图形衬底上的图形高度接近。当3D GaN层生长结束时,3D GaN层把图形衬底的图形围在其中,具有倾斜的侧壁和(0001)向的上表面,而图形上基本没有沉积物。在接下来的2D生长过程里,GaN沿倾斜侧面快速生长,使得侧面上的穿透性位错产生弯曲,从而减少GaN薄膜的穿透性位错。经过对3D条件的优化,GaN薄膜的穿透性位错降低到1×108cm-2,XRD测试得到的(002),(102)半宽分别达到211弧秒和219弧秒。 相似文献
18.
高铭台 《电子科学学刊(英文版)》1988,5(3):220-227
Clean Si(100)and(111)surfaces produced by the Ar~+ ion bombardment and high temperatureanealing techniques,and the epitaxial growth of Ni on them at room temperatue using molecular beammethod are studied by reflection high energy electron diffraction(RHEED).On the basis of experimentresults,Si(111)7×7 and its negative zone RHEED pattern,Si(100)2×1,Si(111)19~(1/2)×19~(1/2)Ni and Si(100)4×2Ni structures have been obtained,and the lattice structure of nickel silicides produced by epitaxy withlow growth rate(0.15-0.5per min)is the same as that of silicon substrate. 相似文献
19.
Yu. B. Samsonenko G. É. Cirlin V. A. Egorov N. K. Polyakov V. P. Ulin V. G. Dubrovskii 《Semiconductors》2008,42(12):1445-1449
The results of experimental studies on the growth and the morphological and structural properties of GaAs nanowire crystals on different silicon surfaces are reported. It is shown that the nonplanar geometrical layout of growth allows the production of epitaxial nanowire crystals in a system with a large lattice mismatch. The growth on porous substrates, the role of the surface orientation, high-temperature annealing, and presence of an oxide layer at the surface, and some other effects typical of growth of III–V nanowire crystals on the Si surface are studied and analyzed. Intense emission from the array of GaAs nanowire crystals grown on the Si (111) surface is observed. 相似文献
20.
Porous GaAs (100) and (111) substrates with nanostructured (~10 nm) surface profiles are obtained in which pores branching in the 〈111〉 direction form a dense network with a volume density of ~60% under the surface at a depth of ~(50–100) nm. The surface of the substrates and the structure of GaSb layers grown on these substrates are studied. A decrease of 22% in the lattice-parameter mismatch at the GaSb/GaAs(porous) interface compared with that at the GaSb/GaAs(monolithic) interface is observed. Ideas about the chemical mechanisms of pore formation in III–V crystals are developed, and relations connecting the structure of porous layers to the composition of electrolytes and anodization conditions are established. It is shown that the dependence of the layers’ growth rate on lattice elastic strain can be conducive to an enhanced overgrowth of pores and to a transition to planar growth. 相似文献