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Compositional analysis based upon electron holography and a chemically sensitive reflection
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| Author |
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| Abstract |
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| We present a method for compositional analysis of low-dimensional semiconductor heterostructures. The suggested procedure is based upon electron holography and the exploitation of the chemically sensitive (002)-reflection that is available in sphalerite type material. We apply an off-axis imaging condition where the strongly excited (002)-beam is centred on the optic axis. From the centred sideband of the hologram we use the phase of the (000)-beam and the modulus of the amplitude of the chemically sensitive (002)-reflection to evaluate the local composition and the local specimen thickness in an iterative and self-consistent way. The application of the procedure is demonstrated using an AlAs/GaAs(001) superlattice with a nominal period of 5 nm and a layer thickness of 2.5 nm. The concentration profile was fitted with a segregation model from which we obtain a superlattice period of (4.86 +/- 0.03) nm, a total amount of AlAs of (2.5 +/- 0.2) nm per AlAs layer and a segregation efficiency of R=0.51 +/- 0.02. | | |
| Language |
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English
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| Source (journal) |
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CONFERENCE SERIES- INSTITUTE OF PHYSICS | |
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Royal-Microscopical-Society Conference on Microscopy of Semiconducting, Materials, MAR 25-29, 2001, UNIV OXFORD, OXFORD, ENGLAND | |
| Publication |
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Bristol : Iop publishing ltd, 2001
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| ISBN |
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0-7503-0818-4
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| Volume/pages |
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169(2001), p. 33-36
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| ISI |
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000176465200007
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