1. WODEAN, June-07 Some DLTS results…. J.H. Bleka et al. University of Oslo, Department of Physics, Physical Electronics, P.O. 1048 Blindern, N-0316 Oslo, NORWAY and University of Oslo, Centre for Materials Science and Nanotechnology P.O. 1128 Blindern, N-0318 Oslo, NORWAY Department of Physics

2. WODEAN, June-07 Topics - Neutron-irradiated samples; first results -Low temperature defect annealing

3. WODEAN, June-07 Samples – neutron irradiation P + - n - - n + Si diodes, processed by CIS std, (8556-02) MCz, 1 kΩcm, 300 µm 1 MeV neutrons at RT, 3.5x10 11 and 6.7x10 11 cm -2 (”DLTS”) Storage at -20 °C

4. Results – neutron irradiation E c -0.18 eV 0.23 eV 0.43 eV E4

5. Results – neutron irradiation E4 E c -0.18 eV 0.23 eV 0.43 eV

6. Results – neutron irradiation Local Fermi level pinning??!

7. Monakhov et al., Phys. Rev. B65, 245201 (2002) Defect tracks in Si 3 MeV Au single ion impact Vacancy distribution Vines et al., Phys. Rev. B73, 085312 (2006)

8. WODEAN, June-07 Samples – LT defect annealing P + - n - - n + Si diodes, standard process by SINTEF MCz, SFz – as processed MCz, SFz – pre-annealed at 450 º C for 1h MCz, SFz – hydrogenated in HF + 450 º C, 1h 6 MeV electrons at RT, 2-5x10 12 cm -2 Storage at -20 °C

9. P + -n - -n + MCz diode N d ~5x10 12 cm -3 6 MeV e -, 5x10 12 cm -2 Bleka et al., ECS Trans 3, 387 (2006)

10. P + -n - -n + MCz diode N d ~5x10 12 cm -3 6 MeV e -, 5x10 12 cm -2 VO, V 2 =/-, V 2 -/0 and E4 vs time at RT

11. P + -n - -n + MCz diode N d ~5x10 12 cm -3 6 MeV e -, 5x10 12 cm -2 Loss of VO, V 2 =/- and V 2 -/0 vs loss of E4

12. P + -n - -n + MCz diode N d ~5x10 12 cm -3 6 MeV e -, 5x10 12 cm -2 Difference between DLTS spectra E5 E4 E c -0.37 eV  app ~10 -14 cm 2 E5 E c -0.45 eV  app ~3x10 -15 cm 2

13. Further results (I) E4/E5 occur with the same relative initial concentration (~25% of [V 2 ]) and exhibit the same annealing rate at RT irrespective of MCz (as-processed, pre-annealed, pre-annealed+hydrogenated), SFz ( as-processed, pre-annealed, pre-annealed+hydrogenated ) and DOFZ (as-processed, pre-annealed, pre-annealed+hydrogenated)

14. Further results (II) Isothermal annealing of E4/E5 at 22 °C (RT), 40.5 °C, 55 °C and 65 °C yield; - First order kinetics (exponential decay) - Activation energy of ~1.27 eV Prefactor of ~2.1x10 15 s -1 Cf values for reverse annealing by Moll et al.; Activation energy: ~1.33 eV Prefactor: ~1.5x10 15 s -1 !!!!!

15. P + -n - -n + SFz diode N d ~4x10 12 cm -3 6 MeV e -, 2x10 12 cm -2 Filling pulse measurements for the VO peak C s C i (and C i ) is not involved in the annealing of E4/E5

16. Speculations V + Y  E4 V + O i → VO [Y] ~ [E4][O i ]/[VO] ≈ 2x10 16 cm -3 Y=C s ?? Not consistent with the results for oxygen-lean SFz

17. Speculations V + Y  E4 V + O i → VO [Y] ~ [E4][O i ]/[VO] ≈ 2x10 16 cm -3 Y=C s ?? Not consistent with the results for oxygen-lean SFz E4 → VO + Y Y = Si i ?? Further work remains

18. Financial support from -the Norwegian Research Council (NFR – Strategic programs on micro/nanotechnology and materials science (NANO/FUNMAT)) -the Nordic Research Training Academy (NorFA) - University of Oslo (Functional materials program) is gratefully acknowledged. Acknowledgements