Berlin 2012 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 24: Poster Session: Ge/Si/SiC / III - V Semiconductors
HL 24.20: Poster
Monday, March 26, 2012, 16:00–19:00, Poster D
DLTS study on deep levels after aluminum gettering in FZ silicon — •Sarina Grevsmühl, Patricia Krenckel, Doaa Abdelbarey, and Michael Seibt — IV. Physikalisches Institut, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
In silicon device fabrication gettering is an important process for reducing metal contamination. In particular, iron is known to have detrimental effects on the electrical performance of these devices due to its deep levels in the silicon band gap which reduce minority carrier lifetime [1]. Recently it was reported that illumination after performing an aluminum gettering step on iron contaminated p-type FZ silicon introduces a deep level ("FeD") that has tentatively been attributed to an iron vacancy complex [2].
In this work aluminum gettering was performed after iron indiffusion into boron-doped FZ silicon. Additionally, the samples were exposed to white light. The material was characterized using deep level transient spectroscopy (DLTS) on Schottky contacts. Along with the signal corresponding to the FeD defect and the iron interstitial level, a level probably due to divacancies was observed with a concentration of 5· 1012 cm−3 in illuminated samples. Results on the effects of thermal annealing, illumination and Schottky contact preparation on these deep levels will be reported on this contribution.
This work was financially supported by the BMU.
[1] A. A. Istratov at al., Appl. Phys. A 70, 489-534 (2000)
[2] D. Abdelbarey et al., J. Appl. Phys. 108, 043519 (2010)