ISSN:
1432-0630
Keywords:
68.55
;
68.65
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract A method is described for the quantitative characterization of strained Si/Si x Ge1−x multilayers and interfaces by high-resolution transmission electron microscopy (HRTEM) in [110] and [100] crystal projections. The method relies on systematic variations of the image contrast with variations of the local composition x for certain ranges of objective lens defocus Δf and specimen thickness t and takes tetragonal lattice distortions fully into account. From an extensive study of the image formation process for Si x Ge1−x alloys and coherent Si/Si x Ge1−x interfaces, ranges of Δf and t were identified by Bloch-wave and multi-slice image simulations at 400 keV for which a quasi-linear functional relationship between the composition x and the first-order Fourier coefficients of the image intensity exists. By application of a novel image-processing algorithm, which allows a precise measurement of image Fourier coefficients in geometrically distorted lattice images, local composition values x can be determined at near-atomic resolution with an accuracy of Δx ≤ ±0.1 and interface sharpness can be detected at the atomic level. Recent applications of the method to the characterization of interfaces of strained Si x Ge1−x layers and short-period Si m Ge n superlattices fabricated by different deposition techniques will be presented.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00331779
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