Controversy of critical layer thickness for InGaAs/GaAs strained-layer epitaxy

Journal Article · Mon Feb 01 00:00:00 EST 1988 · Appl. Phys. Lett.; (United States)

DOI:https://doi.org/10.1063/1.99471· OSTI ID:5740125

Gourley, P L; Fritz, I J; Dawson, L R

The critical layer thickness for In/sub x/Ga/sub 1-//sub x/As layers in In/sub x/Ga/sub 1-//sub x/As/GaAs single strained quantum wells (SSQW's) and strained-layer superlattices (SLS's) are investigated. Photoluminescence microscopy (PLM) images and x-ray rocking curves for two series of SSQW and SLS structures corresponding to many different layer thicknesses were obtained. We find that the PLM technique, which directly images dislocations and is sensitive to low dislocation densities, is much more suitable for determining the onset of dislocation creation. The x-ray technique can detect lattice relaxation by dislocations but only at relatively high densities of dislocations. Using the former technique, we determine critical thicknesses of 190 A for SSQW's and 250 A for SLS's with xapprox. =0.2. These results are near the theoretical predictions of J. W. Matthews, S. Mader, and T. B. Light (J. Appl. Phys. 41, 3800 (1970)) (150 and 300 A, respectively) and are much lower than results obtained by x-ray or other techniques which sense lattice relaxation.

• Research Organization: Sandia National Laboratories, Albuquerque, New Mexico 87185
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5740125
• Journal Information: Appl. Phys. Lett.; (United States), Vol. 52:5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
GALLIUM ARSENIDES
DISLOCATIONS
EPITAXY
INDIUM ARSENIDES
SUPERLATTICES
FABRICATION
THICKNESS
CRYSTAL DEFECTS
STRAINS
THIN FILMS
ARSENIC COMPOUNDS
ARSENIDES
CRYSTAL STRUCTURE
DIMENSIONS
FILMS
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
LINE DEFECTS
PNICTIDES
360602* - Other Materials- Structure & Phase Studies