Interference structures in double-crystal X-ray rocking curves from very thin multiple epitaxial layers

ABSTRACTRelaxation in a 3μm epitaxial layer of GaAsSb on GaAs, a 1μm layer of InGaAs on InP and an InGaAs superlattice on InP has been investigated by double crystal X-ray diffractometry and double crystal X-ray synchrotron topography and found to be asymmetric. The origins of assymetric relaxation are discussed and the sensitivity of diffractometry and topography to the detection of layer relaxation compared.

Download Full-text

X-Ray DCD and EPMA Measurements of Al Concentration in Epitaxial AlxGa1-xAs/GaAs Layers

Advances in X-ray Analysis ◽

10.1154/s0376030800018826 ◽

1992 ◽

Vol 36 ◽

pp. 221-229

Author(s):

D.A. Macquistan ◽

I.C. Bassignana ◽

A.J. SpringThorpe ◽

R. Packwood ◽

V. Moore

Keyword(s):

Epitaxial Layers ◽

X Ray Diffraction ◽

Double Crystal ◽

X Ray ◽

Al Content ◽

The Relationship ◽

Composition Measurements

AbstractDouble Crystal X-Ray Diffraction (DCD) is often used to determine the Al content of AlxGa1-xAs/GaAs epitaxial layers. Assessing composition from a measurement of mismatch is problematic because it invokes a number of assumptions. This study bypasses these difficulties by comparing the measurement of mismatch directly with Al composition measurements made by electronprobe microanalysis. A study of coherent epitaxial AlxGa1-xAs layers showed that mismatch varies linearly with composition. The equation Al (x) = |ΔΘ| / 368 summarizes the relationship over the coherent range, where |ΔΘ| is measured in arc seconds.

Download Full-text

X-Ray Characterisation of Boron Delta Layers in Si and SiGe

MRS Proceedings ◽

10.1557/proc-220-115 ◽

1991 ◽

Vol 220 ◽

Cited By ~ 6

Author(s):

A. R. Powell ◽

R. A. Kubiak ◽

T. E. Whall ◽

E. H. C. Parker ◽

D. K. Bowen

Keyword(s):

High Temperature ◽

Epitaxial Layers ◽

X Ray Diffraction ◽

Double Crystal ◽

X Ray ◽

Carrier Confinement ◽

Delta Layer ◽

Non Destructive ◽

Sheet Density

ABSTRACTWe demonstrate the growth, by MBE, of high sheet density B delta layers in both Si and SiGe epitaxial layers. Double Crystal X-Ray Diffraction is shown to be a non-destructive method of characterising the width of very narrow (0.3 nm) delta layers and the sheet density of the activated B. The ability of delta layers to withstand high temperature anneals is considered and it is found that a 750 °C anneal for 1 hour broadens the delta layer to beyond the width required for carrier confinement.

Download Full-text

Observation of a triclinic lattice distortion of InxGa1−xAs (100)-oriented epitaxial layers by high-resolution double-crystal X-ray diffraction

Solid State Communications ◽

10.1016/0038-1098(94)90562-2 ◽

1994 ◽

Vol 91 (8) ◽

pp. 635-638 ◽

Cited By ~ 14

Author(s):

C. Giannini ◽

L. De Caro ◽

L. Tapfer

Keyword(s):

High Resolution ◽

Lattice Distortion ◽

Epitaxial Layers ◽

X Ray Diffraction ◽

Double Crystal ◽

X Ray

Download Full-text

Characterization of Gasb-Based Alloy Semiconductors

MRS Proceedings ◽

10.1557/proc-216-169 ◽

1990 ◽

Vol 216 ◽

Author(s):

H. Uekita ◽

N. Kitamura ◽

M. Ichimura ◽

A. Usami ◽

T. Wada

Keyword(s):

Raman Spectroscopy ◽

Liquid Phase ◽

Epitaxial Layer ◽

Structural Defects ◽

Epitaxial Layers ◽

X Ray Diffraction ◽

Double Crystal ◽

X Ray ◽

Alloy Semiconductors

ABSTRACTGaSb, AlxGa1-xSb, and AlxGa1-xSb epitaxial layers were grown by the liquid-phase epitaxy and characterized by photoluminescence, Raman spectroscopy, and double-crystal X-ray diffraction. The concentration of residual acceptors which are related to structural defects decreased with lowering growth temperature, but the GaSb epitaxial layer grown at an extremely low temperature of 270°C had poor crystalline quality. The AlxGa1-xSb (x≥0.15) and AlxGa1-xSb (x=0.02) epitaxial layers grown at 270 °C, however, had much better quality than the GaSb epitaxial layer grown at the same temperature.

Download Full-text

Non-Destructive Analysis of Thin III-V Epitaxial Layers Using a Tabletop Double Crystal X-Ray Diffractometer

MRS Proceedings ◽

10.1557/proc-208-125 ◽

1990 ◽

Vol 208 ◽

Cited By ~ 1

Author(s):

R. N. Sacks

Keyword(s):

Epitaxial Layers ◽

X Ray Diffraction ◽

Double Crystal ◽

X Ray ◽

Glancing Angle ◽

Destructive Analysis ◽

Excellent Method ◽

Commercial Software Package ◽

Non Destructive

ABSTRACTSome of today's most promising and interesting semiconductor devices use only a few thin epitaxial layers of III-V materials, where each layer may be only 100 to 1,000A thick. There is a need for fast, accurate, non-destructive analysis techniques for these structures. Double-crystal x-ray diffraction has proven to be an excellent method for measuring composition, thickness, interface sharpness, and overall crystalline quality of III-V heterostructures. Data is presented on the use of a Bede QC1 automated table-top double-crystal diffractometer for the analysis of (AI,Ga)As, (ln,Ga)As, and GaAs epitaxial layers grown by Molecular Beam Epitaxy (MBE). It is shown that this technique can directly detect and analyze single layers of (In,Ga)As as thin as 200A, and in some cases, can indirectly detect layers of GaAs or (AI,Ga)As as thin as 100A without unusual measures such as glancing angle diffraction. The rocking curve results are compared with values predicted by RHEED intensity oscillation measurements, and with computer simulations using a commercial software package.

Download Full-text

X-RAY DIFFRACTION ANALYSIS OF EPITAXIAL STRUCTURES

MRS Proceedings ◽

10.1557/proc-56-121 ◽

1985 ◽

Vol 56 ◽

Author(s):

BRUCE M. PAINE

Keyword(s):

Diffraction Analysis ◽

Kinematic Model ◽

Single Layer ◽

Epitaxial Layers ◽

X Ray Diffraction ◽

Double Crystal ◽

X Ray ◽

Depth Profiles ◽

Atomic Displacements ◽

Structure Factors

AbstractThe technique is described for use of x-ray double crystal diffractometry for analysis of epitaxial structures. This method has been shown to be very useful for characterizing a wide variety of configurations, ranging from single epitaxial layers to damaged superlattices. It yields depth profiles of structure factors and strains relative to the substrate, which can be directly related to layer thicknesses and compositions. Information about dislocations and random atomic displacements is also present. The key to this technique is computer fitting of the x-ray data with a model for the diffraction process, utilizing trial profiles for the strain and structure factors of the epitaxial layers. In the work to be presented a kinematic model for the diffraction is used. The technique is demonstrated with analyses of an Alx Ga(1−x) As single layer on GaAs, an AlSb/GaSb superlattice on GaSb, epitaxial CoSi2 on Si, and ion-implanted and annealed AlxGa(1−x)As superlattices on GaAs.

Download Full-text