The structure of GaAs/Si(211) heteroepitaxial layers

Conference · Wed May 01 00:00:00 EDT 1985

OSTI ID:6228993

Liliental-Weber, Z; Weber, E R; Washburn, J; Liu, T Y; Kroemer, H

Gallium arsenide films grown on (211)Si by molecular-beam epitaxy have been investigated using transmission electron microscopy. The main defects observed in the alloy were of misfit dislocations, stacking faults, and microtwin lamellas. Silicon surface preparation was found to play an important role on the density of defects formed at the Si/GaAs interface. Two different types of strained-layer superlattices, InGaAs/InGaP and InGaAs/GaAs, were applied either directly to the Si substrate, to a graded layer (GaP-InGaP), or to a GaAs buffer layer to stop the defect propagation into the GaAs films. Applying InGaAs/GaAs instead of InGaAs/InGaP was found to be more effective in blocking defect propagation. In all cases of strained-layer superlattices investigated, dislocation propagation was stopped primarily at the top interface between the superlattice package and GaAs. Graded layers and unstrained AlGaAs/GaAs superlattices did not significantly block dislocations propagating from the interface with Si. Growing of a 50 nm GaAs buffer layer at 505/sup 0/C followed by 10 strained-layer superlattices of InGaAs/GaAs (5 nm each) resulted in the lowest dislocation density in the GaAs layer (approx.5 x 10/sup 7//cm/sup 2/) among the structures investigated. This value is comparable to the recently reported density of dislocations in the GaAs layers grown on (100)Si substrates. Applying three sets of the same strained layers decreased the density of dislocations an additional approx.2 to 3 times.

• Research Organization: Lawrence Berkeley Lab., CA (USA); California Univ., Santa Barbara (USA). Dept. of Electrical and Computer Engineering
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6228993
• Report Number(s): LBL-23462; CONF-870438-24; ON: DE87011223
• Resource Relation: Conference: Spring meeting of the Materials Research Society, Anaheim, CA, USA, 21 Apr 1987; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
GALLIUM ARSENIDES
MOLECULAR BEAM EPITAXY
DISLOCATIONS
INDIUM ARSENIDES
SILICON
SUPERLATTICES
TRANSMISSION ELECTRON MICROSCOPY
ARSENIC COMPOUNDS
ARSENIDES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTRON MICROSCOPY
ELEMENTS
EPITAXY
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
LINE DEFECTS
MICROSCOPY
PNICTIDES
SEMIMETALS
360602* - Other Materials- Structure & Phase Studies