Characterization of Interfacial Roughness in Semiconductor Heterostructures by X-Ray Reflectivity

ABSTRACTThe reflection of monochromatic x-rays by a layered heterostructure can be utilized as a nondestructive probe to obtain information on the interfacial roughness in the material. Interference between x-rays reflected from the top surface and the interfaces can give rise to pronounced oscillations in the reflectivity as a function of the grazing incidence angle. We have made use of this technique to investigate the interfacial roughness in semiconductor heterostructures grown by molecular beam epitaxy.

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Generalized grazing-incidence-angle X-ray diffraction (G-GIXD) using image plates

Journal of Synchrotron Radiation ◽

10.1107/s090904959800123x ◽

1998 ◽

Vol 5 (3) ◽

pp. 488-490 ◽

Cited By ~ 5

Author(s):

Yasuo Takagi ◽

Masao Kimura

Keyword(s):

Incidence Angle ◽

Incident Beam ◽

Grazing Incidence ◽

X Rays ◽

X Ray Diffraction ◽

X Ray ◽

Surface And Interface ◽

Out Of Plane ◽

Grazing Incidence Angle ◽

Interface Layers

A new and more `generalized' grazing-incidence-angle X-ray diffraction (G-GIXD) method which enables simultaneous measurements both of in- and out-of-plane diffraction images from surface and interface structures has been developed. While the method uses grazing-incidence-angle X-rays like synchrotron radiation as an incident beam in the same manner as in `traditional' GIXD, two-dimensional (area) detectors like image plates and a spherical-type goniometer are used as the data-collection system. In this way, diffraction images both in the Seemann–Bohlin (out-of-plane) and GIXD geometry (in-plane) can be measured simultaneously without scanning the detectors. The method can be applied not only to the analysis of the in-plane crystal structure of epitaxically grown thin films, but also to more general research topics like the structural analysis of polycrystalline mixed phases of thin surface and interface layers.

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Structural Characterization of GaN Epilayers Grown on Patterned Sapphire Substrates

MRS Proceedings ◽

10.1557/proc-864-e4.8 ◽

2005 ◽

Vol 864 ◽

Author(s):

Chang-Soo Kim ◽

Ji-Hyun Moon ◽

Sang-Jun Lee ◽

Sam-Kyu Noh ◽

Je Won Kim ◽

...

Keyword(s):

Incidence Angle ◽

Surface Region ◽

Grazing Incidence ◽

X Rays ◽

X Ray Diffraction ◽

X Ray ◽

Patterned Substrate ◽

Sapphire Substrates ◽

Patterned Sapphire Substrates

AbstractThe structural properties of GaN epitaxial layers grown on patterned sapphire substrates by MOCVD have been investigated using HRXRD(high-resolution X-ray diffraction), GIXRD(grazing incidence X-ray diffraction) and PL(photoluminescence). For X-ray characterizations rocking curves for GaN (10·5), (00·2), (11·4) and (11·0) reflections for which incidence angles of X-rays are 32.0°, 17.3°, 11.0° and 0.34°, respectively, were measured. For (10·5), (00·2) and (11·4) reflections FWHMs of the rocking curves for a patterned substrate were broader than those for a unpatterned substrate, for (11·0) reflection, however, FWHM for a patterned substrate was much narrower than that for a unpatterned substrate. The normalized FWHM for all reflections decreases as the incidence angle of X-ray decreases. The results indicate that the crystalline quality in the surface region of the epilayer on a patterned substrate was especially improved because the penetration depth of X-ray depends on the incidence angle. The intensity of PL peak of the epilayer for a patterned substrate increased compared to that for a unpatterned substrate, and the increase in PL intensity is attributed to the reduction in dislocation density at the surface region revealed the by X-ray results.

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Imaging X-ray fluorescence microscope with a Wolter-type grazing-incidence mirror

Journal of Synchrotron Radiation ◽

10.1107/s0909049597018542 ◽

1998 ◽

Vol 5 (3) ◽

pp. 1117-1118 ◽

Cited By ~ 7

Author(s):

S. Aoki ◽

A. Takeuchi ◽

M. Ando

Keyword(s):

Spatial Resolution ◽

Incidence Angle ◽

Grazing Incidence ◽

Fluorescence Microscope ◽

X Rays ◽

X Ray ◽

Photon Factory ◽

Grazing Incidence Angle ◽

Fluorescence Images ◽

Better Than

A Wolter-type grazing-incidence mirror was used as an objective for an imaging X-ray fluorescence microscope. The microscope was constructed at the beamline 6C2 of the Photon Factory. The shortest wavelength used was ∼0. 1 nm, which was limited by the grazing-incidence angle of the mirror. To demonstrate the possibility of recording X-ray fluorescence images, several fine grids were used as test specimens. Characteristic X-rays emitted from each specimen could be clearly imaged. Spatial resolution was estimated to be better than 10 µm.

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Gas‐source molecular‐beam epitaxy using Si2H6and GeH4and x‐ray characterization of Si1−xGex(0≤x≤0.33) alloys

Journal of Applied Physics ◽

10.1063/1.350639 ◽

1992 ◽

Vol 71 (10) ◽

pp. 4916-4919 ◽

Cited By ~ 7

Author(s):

S. H. Li ◽

S. W. Chung ◽

J. K. Rhee ◽

P. K. Bhattacharya

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

X Ray ◽

Gas Source

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The influence of X-ray coherence length on TXRF and XSW and the characterization of nanoparticles observed under grazing incidence of X-rays

Journal of Analytical Atomic Spectrometry ◽

10.1039/b811178b ◽

2009 ◽

Vol 24 (6) ◽

pp. 792 ◽

Cited By ~ 35

Author(s):

Alex von Bohlen ◽

Markus Krämer ◽

Christian Sternemann ◽

Michael Paulus

Keyword(s):

Coherence Length ◽

Grazing Incidence ◽

X Rays ◽

X Ray

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X-RAY DIFFRACTION FOR SURFACES AND BURIED INTERFACES

Surface Review and Letters ◽

10.1142/s0218625x00000452 ◽

2000 ◽

Vol 07 (04) ◽

pp. 437-446 ◽

Cited By ~ 1

Author(s):

G. RENAUD

Keyword(s):

Grazing Incidence ◽

X Rays ◽

X Ray Diffraction ◽

X Ray ◽

Grain Sizes ◽

Buried Interfaces ◽

Surfaces And Interfaces ◽

Coherent Interfaces

The application of X-rays to the structural characterization of surfaces and interfaces, in situ and in UHV, is discussed on selected examples. Grazing incidence X-ray diffraction is not only a very powerful technique for quantitatively investigating the atomic structure of surfaces and interfaces, but is also very useful for providing information on the interfacial registry for coherent interfaces or on the strain deformation, island and grain sizes for incoherent epilayers.

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Investigation of Semiconductor Heterostructures by White Beam Synchrotron X-Ray Topography in Grazing Bragg-Laue and Conventional Bragg Geometries

Advances in X-ray Analysis ◽

10.1154/s0376030800008892 ◽

1991 ◽

Vol 35 (A) ◽

pp. 247-253

Author(s):

G.-D. Yao ◽

J. Wu ◽

T. Fanning ◽

M. Dudley

Keyword(s):

Penetration Depth ◽

Grazing Incidence ◽

Semiconductor Heterostructures ◽

Misfit Dislocations ◽

Strained Layers ◽

X Ray ◽

Main Reflection ◽

White Beam ◽

Topographic Imaging

AbstractWhite beam synchrotron X-ray topography has been applied both to the characterization of two semiconductor heterostructures, GaAs/Si and InxGa1-xAs/GaAs strained layers, and a substrate to be used for growing semiconductor epilayers, Cd1-xZnxTe. In the case of the heterostructures, misfit dislocations were observed using depth sensitive X-ray topographic imaging in grazing incidence Bragg-Laue geometries. The X-ray penetration depth, which can be varied from several hundreds of angstroms to hundreds of micrometers by rotating about the main reflection vector, which in this specific case was (355), is governed by kinernatical theory. This is justified by comparing dislocation contrast and visibility with the extent of the calculated effective misorientalion field in comparison to the effective X-ray penetration depth. For the case of Cd1-xZnxTe, twin configurations are observed, and their analysis is presented.

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The Characterization of Thin Films and Layered Structures Using X-RAY Absorption and Reflection at Grazing Incidence

MRS Proceedings ◽

10.1557/proc-37-437 ◽

1984 ◽

Vol 37 ◽

Cited By ~ 1

Author(s):

S. M. Heald ◽

J. M. Tranquada ◽

D. O. Welch ◽

H. Chen

Keyword(s):

Thin Films ◽

Fine Structure ◽

High Resolution ◽

Grazing Incidence ◽

X Rays ◽

X Ray ◽

Surface And Interface ◽

Interface Structures ◽

X Ray Absorption

AbstractX-rays at grazing incidence have a short, controllable penetration depth and are well suited as a probe of surface and interface structures. This paper examines the possibility applying grazing-incidence reflectivity and Extended X-Ray Absorption Fine Structure (EXAFS) measurements to such systems. Results are presented for an Al-Cu couple for which both high resolution reflectivity and interface EXAFS measurements are made. The latter results are the first interface specific EXAFS data to be reported. Distinct changes in both signals are observed upon annealing, demonstrating the potential of the techniques.

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