Reorientation of misfit dislocations during annealing in InGaAs/GaAs(001) interfaces
- Lawrence Berkeley Lab., CA (United States)
- Sandia National Labs., Albuquerque, NM (United States)
Transmission electron microscopy is applied to investigate the effect of postannealing on misfit dislocations in an In{sup 0.2}Ga{sup 0.8}As/GaAs(001) heterostructure. An orthogonal array of 60{degree} dislocations along [110] and [110] directions was observed in the interfaces of the samples grown by MBE at 520C. When the as-grown samples were annealed at temperatures ranging from 600 to 800C, the 60{degree} dislocations were gradually reoriented by dislocation reactions occurring at the 90{degree} intersections followed by nonconservative motion driven by dislocation line tension and the residual elastic misfit strain. The final result of this process was a dislocation array lying along [100] and {center_dot} [010] directions. The reoriented u =<100> dislocation has a Burgers vector b = a/2 <101>, which is the same as that of 60{degree} dislocation, but the edge component of its Burgers vector in the (001) interfacial plane is larger than that of 60{degree} dislocation by a factor of {radical}2, resulting in a greater contribution to elastic strain relaxation. This nonconservative reorientation of 60{degree} dislocations to form the u=<100> dislocations represents a new strain relaxation mechanism in diamond or zinc blende semiconductor heterostructures.
- Research Organization:
- Lawrence Berkeley Lab., CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC03-76SF00098; AC04-76DP00789
- OSTI ID:
- 10165260
- Report Number(s):
- LBL-34070; CONF-930405-19; ON: DE93015046
- Resource Relation:
- Conference: Spring meeting of the Materials Research Society,San Francisco, CA (United States),12-16 Apr 1993; Other Information: PBD: Apr 1993
- Country of Publication:
- United States
- Language:
- English
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