Dislocation reduction in epitaxial GaAs on Si (100)
We have studied the nucleation and propagation of threading dislocations in GaAs on Si epitaxial layers, and have found several techniques which are effective in reducing their density. The use of substrates properly tilted off (100) reduces the dislocation density as the presence of steps helps create perfect edge dislocations with their Burgers vector parallel to the interface and thus do not propagate into the bulk epitaxial layer. Cross sections by transmission electron microscopy show that the incorporation of an InGaAs/GaAs strained-layer superlattice reduces the density of threading dislocations above it by a factor of 10, clearly demonstrating the effectiveness of this technique. These methods lead to a dislocation density of 10/sup 3/ cm/sup -2/ near the surface of 2 ..mu..m layers which is five orders of magnitude lower than what has been obtained previously. We have also found that the density of oval defects is much lower for GaAs on Si than for GaAs on GaAs.
- Research Organization:
- University of Illinois at Urbana-Champaign, 1101 West Springfield Avenue, Urbana, Illinois 61801
- DOE Contract Number:
- AC02-76ER01198
- OSTI ID:
- 5830119
- Journal Information:
- Appl. Phys. Lett.; (United States), Journal Name: Appl. Phys. Lett.; (United States) Vol. 48:18; ISSN APPLA
- Country of Publication:
- United States
- Language:
- English
Similar Records
The structure of GaAs/Si(211) heteroepitaxial layers
Low threading dislocation density GaAs growth on on-axis GaP/Si (001)
Related Subjects
360602* -- Other Materials-- Structure & Phase Studies
ARSENIC COMPOUNDS
ARSENIDES
CROSS SECTIONS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DISLOCATIONS
ELECTRON MICROSCOPY
ELEMENTS
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
INDIUM ARSENIDES
INDIUM COMPOUNDS
LINE DEFECTS
MICROSCOPY
NUCLEATION
PNICTIDES
SEMIMETALS
SILICON
STRAINS
SUPERLATTICES
TRANSMISSION ELECTRON MICROSCOPY