Energetics of misfit- and threading-dislocation arrays in heteroepitaxial films

Journal Article · Mon Jul 15 00:00:00 EDT 1991 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.44.1154· OSTI ID:5328307

Rockett, A ^[1]; Kiely, C J ^[2]

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1. The Coordinated Science Laboratory, The Materials Research Laboratory, (USA) Department of Materials Science and Engineering, University of Illinois, 1101 West Springfield Avenue, Urbana, IL
2. Department of Materials Science and Engineering, University of Liverpool, P.O. Box 147, Liverpool, L69 3BX, United Kingdom (GB)

A theory relating the separation of misfit dislocations to lattice mismatch and film thickness in heteroepitaxial thin films is presented. From this, the energy as a function of dislocation spacing is calculated and is shown to include an attractive and repulsive region. The dislocation-formation energy and Peierls barrier to network ordering are shown to be estimable on the basis of measured dispersions in dislocation spacings. The spacing is predicted to be more uniform as the mismatch increases. Thermodynamic functions, such as the compressibility of the dislocation network, can be calculated from the energy--dislocation-spacing relationship. A formula relating the equilibrium dislocation spacing to film thickness, mismatch, and misfit-dislocation character is also derived. Finally, the density of threading dislocations is calculated both at the heterojunction and at the film surface, by assuming a threading-dislocation reaction process. The results are shown to be in good agreement with the experimental data for Si{sub {ital x}}Ge{sub 1{minus}{ital x}}/Si, InSb/GaAs, and In{sub {ital x}}Ga{sub 1{minus}{ital x}}As/GaAs structures.

• DOE Contract Number: AC02-76ER01198
• OSTI ID: 5328307
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 44:3; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALLOY SYSTEMS
ALLOYS
ARSENIC COMPOUNDS
ARSENIDES
BINARY ALLOY SYSTEMS
CRYSTAL DEFECTS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DATA
DISLOCATIONS
EPITAXY
EXPERIMENTAL DATA
FILMS
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
GERMANIUM ALLOYS
HETEROJUNCTIONS
INDIUM ARSENIDES
INDIUM COMPOUNDS
INFORMATION
JUNCTIONS
LINE DEFECTS
MATERIALS
NUMERICAL DATA
PNICTIDES
SEMICONDUCTOR JUNCTIONS
SEMICONDUCTOR MATERIALS
SILICON ALLOYS
THIN FILMS