Germanium {sup 70}Ge/{sup 74}Ge isotope heterostructures: An approach to self-diffusion studies

Journal Article · Thu Jun 15 04:00:00 EDT 1995 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.51.16817· OSTI ID:69923

Fuchs, H D; Walukiewicz, W; Haller, E E ^[1]; Dondl, W; Schorer, R; Abstreiter, G ^[2]; Rudnev, A I; Tikhomirov, A V; Ozhogin, V I ^[3]

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1. University of California at Berkeley and Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)
2. Walter-Schottky-Institut, Technische Universitaet Muenchen, Am Coulombwall, D-85748 Garching (Germany)
3. RRC Kurchatov Institute of Atomic Energy, 123182 Moscow (Russian Federation)

We demonstrate a technique to study self-diffusion in germanium, using isotope heterostructures ({sup 70}Ge/{sup 74}Ge). After interdiffusing the nominally undoped layers of {sup 70}Ge and {sup 74}Ge at temperatures between 543 and 690 {degree}C, the diffusion profiles are measured with secondary-ion-mass spectroscopy. The analysis of the experimental data allows an accurate determination of the self-diffusion enthalpy and the self-diffusion entropy. The isotope heterostructures are especially well suited for self-diffusion studies because the diffusion takes place at the interfaces {ital inside} the crystal. Thus, no surface effects or limited amounts of tracers complicate the measurements. We compare our results with those obtained with the standard techniques where the tracer self-diffusion coefficients are determined based on studying the redistribution of radioactive tracers, initially deposited on the specimen surface. Utilizing the {ital stable} isotopes in our experiment avoids complications due to decay of the {ital radioactive} tracers encountered in the traditional measurements.

• Research Organization: Lawrence Berkeley National Laboratory
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 69923
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 23 Vol. 51; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
ENTHALPY
ENTROPY
GERMANIUM 70
GERMANIUM 74
HETEROJUNCTIONS
INTERFACES
ION MICROPROBE ANALYSIS
MASS SPECTROSCOPY
SELF-DIFFUSION
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0400-1000 K