Dresden 2006 – scientific programme

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HL: Halbleiterphysik

HL 50: Poster II

HL 50.5: Poster

Thursday, March 30, 2006, 16:30–19:00, P3

Investigation of copper transport in silicon — •Mike Thieme and Jörg Weber — Technische Universität Dresden, 01062 Dresden, Germany

Copper transport was studied in p-type FZ-silicon using the DLTS-signal of the Cu-pairs to monitor the interstitial Cu concentration. Atomic copper was deposited at room temperature onto the sample surface from a diluted HF-solution containing ions of the metal. In the bulk, it was impossible to detect copper after the deposition (detection limit 10¹⁰ atoms/cm³). Even a subsequent annealing up to 350 ^∘C in helium atmosphere did not produce detectable copper traces. The scavenging of copper was studied in FZ-Si samples containing Cu-pairs. The dissociation energy of the pairs is 1.02 eV and an annealing step at 250 ^∘C is necessary to break them up. Our investigations show that the amount of outdiffusing copper depends on the annealing gas. This opens a new way to control the interstitial copper contamination in silicon.

Acknowledgment: This work has been supported by the DFG (WE1319/15-1).