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Title: Optical imaging of dislocations in strained-layer superlattices and lattice-mismatched epilayers

Conference ·
OSTI ID:6179052

We have developed a convenient photoluminescence microimaging technique to probe misfit dislocations in epitaxially grown semiconductor alloys and multilayers. Using this technique, we have examined the microscopic optical quality of thick (approx.1 ..mu..m) III-V semiconductor epitaxial layers, mismatched to their substrates. The layers include several kinds of (100) strained-layer superlattices (GaP/GaAs/sub x/P/sub 1-x/ on GaP and GaAs/GaAs/sub 1-x/P on GaAs grown by MOCVD, and GaAs/In/sub x/Ga/sub 1-x/As on GaAs grown by MBE) and associated alloys. For each type of superlattice, we have studied a large number of samples corresponding to different compositions and layer thicknesses. The results show that misfit dislocations can be completely eliminated in the uppermost layers of the strained-layer superlattices if these structures have thin layers, less than the critical thickness for elastic accommodation, and sufficient numbers of interfaces to block threading dislocations.

Research Organization:
Sandia National Labs., Albuquerque, NM (USA)
DOE Contract Number:
AC04-76DP00789
OSTI ID:
6179052
Report Number(s):
SAND-85-2664C; CONF-851217-16; ON: DE86004620
Resource Relation:
Conference: Materials Research Society meeting, Boston, MA, USA, 2 Dec 1985
Country of Publication:
United States
Language:
English