J. Phys. Colloques
Volume 50, Numéro C6, Juin 1989Beam Injection Assessment of Defects in Semiconductors
|Page(s)||C6-166 - C6-166|
J. Phys. Colloques 50 (1989) C6-166-C6-166
IN SITU OBSERVATION OF DISLOCATION MOTION IN CdTe USING EBICJ. KRONEWITZ et W. SCHRÖTER
4. Physikalisches Institut and Sonderforschungsbereich 126, University of Göttingen, D-3400 Göttingen, Bunsenstrasse 11-15, F.R.G.
Dislocations in compound semiconductors are thought to be decorated with point defect clouds that may dominate the observed electrical activity. We were able to separate the point defect cloud from the dislocation by in situ observation of dislocation motion using a deformation apparatus installed in the scanning electron microscope. CdTe crystals were deformed by compression at room temperature. Concerning the EBIC-contrasts associated with moving dislocations we have distinguished two cases : 1) Some dislocations showed almost no EBIC-contrast between their initial and their final position. Dislocation motion was only detectable by the occurence and growth of a new contrast while the contrast at the initial position slowly disappeared. We have concluded that in this case the EBIC-contrasts were mainly due to point defect clouds which were left behind when the dislocations moved and had to be re-established at the final position. 2) Other dislocations in the same specimen moving in the same direction showed EBIC-contrasts of constant intensity during motion, even at a velocity of up to 10 microns per second. No contrasts remained at the initial positions of these dislocations. In this case the origin of the EBIC-contrast seemed to be fixed to the dislocation line also during fast motion. Different dislocation types or different types of decorating point defects may be responsible for the different EBIC-contrasts during dislocation motion.