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

WODEAN, June-07

Topics

- Neutron-irradiated samples; first results

- Low temperature defect annealing

WODEAN, June-07

Samples – neutron irradiation

P+- n- - n+ Si diodes, processed by CIS std, (8556-02)

MCz <100>, 1 kΩcm, 300 µm

1 MeV neutrons at RT, 3.5x1011 and 6.7x1011 cm-2 (”DLTS”)

Storage at -20 °C

Results – neutron irradiation

Ec-0.18 eV

0.23 eV

0.43 eV

E4

Results – neutron irradiation

E4

Ec-0.18 eV

0.23 eV

0.43 eV

Results – neutron irradiation

Local Fermi level pinning??!

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)

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 ºC for 1h

MCz, SFz – hydrogenated in HF + 450 ºC, 1h

6 MeV electrons at RT, 2-5x1012 cm-2

Storage at -20 °C

P+-n--n+ MCz diode

Nd~5x1012 cm-3

6 MeV e-, 5x1012 cm-2

Bleka et al., ECS Trans 3, 387 (2006)

P+-n--n+ MCz diode

Nd~5x1012 cm-3

6 MeV e-, 5x1012 cm-2

VO, V2=/-, V2

-/0 and E4 vs time at RT

P+-n--n+ MCz diode

Nd~5x1012 cm-3

6 MeV e-, 5x1012 cm-2

Loss of VO, V2=/- and V2

-/0 vs loss of E4

P+-n--n+ MCz diode

Nd~5x1012 cm-3

6 MeV e-, 5x1012 cm-2

Difference between DLTS spectraE5

E4Ec-0.37 eVapp~10-14 cm2

E5Ec-0.45 eVapp~3x10-15 cm2

Further results (I)

E4/E5 occur with the same relative initial concentration (~25% of [V2]) 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)

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 eVPrefactor of ~2.1x1015 s-1

Cf values for reverse annealing by Moll et al.;Activation energy: ~1.33 eVPrefactor: ~1.5x1015 s-1 !!!!!