Synchrotron X-ray topographic study of dislocations in GaAs detector crystals grown by vertical gradient freeze technique
- Helsinki Univ. of Technology (Finland). Optoelectronics Lab.; and others
Large area transmission and section topographs of semi-insulating gallium arsenide wafers grown by the gradient freeze technique are made with synchrotron radiation at HASYLAB in Hamburg and at ESRF in Grenoble. Several high-resolution images including stereo pairs are obtained on the same film at a time. A typical dislocation line is an arc of a circle which starts from one surface and ends at the same surface. From the disappearance of the dislocation image and using the g {center_dot} b = 0 criterion it is concluded that the Burgers vector b of the most common dislocations is parallel to <110>. Rather large volumes of the wafer are dislocation-free. Section topographs of epitaxial wafers show defects and strain fields at the interface between an n-type substrate and the epitaxial layers grown by chemical vapor deposition. The results are compared with those obtained from detector performance measurements.
- OSTI ID:
- 323881
- Report Number(s):
- CONF-971201-; TRN: 99:004413
- Resource Relation:
- Conference: 1997 fall meeting of the Materials Research Society, Boston, MA (United States), 1-5 Dec 1997; Other Information: PBD: 1998; Related Information: Is Part Of Semiconductors for room-temperature radiation detector applications 2; James, R.B. [ed.] [Sandia National Labs., Livermore, CA (United States)]; Schlesinger, T.E. [ed.] [Carnegie Mellon Univ., Pittsburgh, PA (United States)]; Siffert, P. [ed.] [Lab. PHASE/CNRS, Strasbourg (France)]; Dusi, W. [ed.] [Inst. TESRE/CNR, Bologna (Italy)]; Squillante, M.R. [ed.] [Radiation Monitoring Devices, Inc., Watertown, MA (United States)]; O`Connell, M. [ed.] [Dept. of Energy, Washington, DC (United States)]; Cuzin, M. [ed.] [LETI/CEA, Grenoble (France)]; PB: 681 p.; Materials Research Society symposium proceedings, Volume 487
- Country of Publication:
- United States
- Language:
- English
Similar Records
Simulation of Threading Dislocation Images in X-ray Topographs of Silicon Carbide Homo-Epilayers
AlGaAs/GaAs avalanche detector array -- 1 Gbit/s x-ray receiver for timing measurements