Large lattice mismatch epitaxy

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:470880

Mahajan, S ^[1]

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1. Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Materials Science and Engineering

The exploitation of novel materials, such as III-V nitrides, for light emitting devices and high temperature electronics requires lattice mismatch epitaxy because bulk crystals for homoepitaxy are not currently available. During the early stages of lattice mismatch epitaxy, island growth is observed in several systems. The evolution of this morphology is attributed to a large value of the substrate/layer interface energy. Origins of misfit and threading dislocations are also considered. Nucleation of misfit dislocations could occur either from steps present on surfaces of islands or from substrate/island edges. Arms of glide loops terminating at the surface in the first case form threading segments in the layer, whereas the coalescence of islands in which misfit dislocations are not aligned with respect to each other lead to threading dislocations in the second case. Existing approaches for lowering threading dislocation densities are also evaluated. A novel approach involving controlled, self-assembly of islands is presented to achieve the preceding objective.

• Sponsoring Organization: Office of Naval Research, Washington, DC (United States)
• OSTI ID: 470880
• Report Number(s): CONF-951155--; ISBN 1-55899-313-4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
CRYSTAL STRUCTURE
DATA
DISLOCATIONS
ELECTRONIC EQUIPMENT
EPITAXY
INTERFACES
LATTICE PARAMETERS
LAYERS
MORPHOLOGY
NUCLEATION
PERFORMANCE
SEMICONDUCTOR MATERIALS