Nucleation of misfit and threading dislocations in GaSb/GaAs(001) heterostructure

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

OSTI ID:468936

Qian, W; Skowronski, M; De Graef, M ^[1]; Kaspi, R ^[2]

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1. Carnegie Mellon Univ., Pittsburgh, PA (United States)
2. Wright State Univ., Dayton, OH (United States)

GaSb thin film grown on GaAs is a promising substrate for fabrication of electronic and optical devices such as infrared photodetectors. However, these two materials exhibit a 7.8% lattice constant mismatch which raises concerns about the amount of extended defects introduced during strain relaxation. It was found that, unlike small lattice mismatched systems such as In{sub x}Ga{sub 1-x}As/GaAs or Ge{sub x}Si{sub 1-x}/Si(100), the GaSb/GaAs interface consists of a quasi-periodic array of 90{degrees} misfit dislocations, and the threading dislocation density is low despite its large lattice mismatch. This paper reports on the initial stages of GaSb growth on GaAs(001) substrates by molecular beam epitaxy (MBE). In particular, we discuss the possible formation mechanism of misfit dislocations at the GaSb/GaAs(001) interface and the origin of threading dislocations in the GaSb epilayer.

• OSTI ID: 468936
• Report Number(s): CONF-960877--; CNN: Contract F33615-95-C1619
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DISLOCATIONS
GALLIUM ANTIMONIDES
GALLIUM ARSENIDES
MICROSTRUCTURE
MOLECULAR BEAM EPITAXY
THIN FILMS