Influence of high-temperature annealing on the characteristics of fast electron-irradiated p-n-structures based on neutron doped silicon

The investigation results of the annealing influence (Тann = 300–800 ºС) on the minority charge currier lifetime tP in the n-base of p-n-structures, manufactured on the base of neutron transmutation doped silicon (NTD) КОФ300, irradiated at room temperature by different fluences (F = 1 · 1014 – 3 · 1016 cm–2) of electrons with the energy of Еe = 4 MeV are presented. It is established that at low electron fluences (F = 1 · 1014 cm–2), the annealing of minority charge currier lifetime tP in the n-base of p-n-structures occurs in two stages: the first – 320–400 ºС and the second – 550–650 ºС. At higher electron fluences (F = 5 · 1015–2 · 1016 cm–2), three annealing stages occur: the first – 400–450 ºС, the second – 520–650 ºС and the third – 710–770 ºС. At this, the structure barrier capacitance C dependences on Тann at high electron fluences show the geometry capacitance up to the annealing temperatures Тann = 400 ºС. In the annealing temperature range of Тann = 420–570 ºС, the increase in С with maximum is seen at Тann = 480 ºС and a subsequent decrease in the geometry capacitance is seen in the annealing temperature range of Тann = 600–670 ºС, and then again the increase in С occurs in the annealing temperature range of Тann = 720–770 ºС reaching the С values corresponding to those of the non-irradiated samples in the annealing temperature range of Тann = 770–800 ºС. The analysis of the DLTS-spectra of the investigated structures has allowed establishing the formation in the annealing process of the deep acceptor level ЕС – 0.68 eV at Тann > 400 ºС, the deep donor level ЕС – 0.32 eV in the annealing temperature range of Тann = 420–570 ºС and the deep acceptor level ЕС – 0.53 eV at Тann > 700 ºС, which satisfactorily explains the dependences of t P and С on Тann obtained in this paper.

radiation defect, radiation-thermal defect, electron irradiation, high-temperature annealing, minority charge carrier lifetime, DLTS-spectroscopy

1. Smirnov L. S. Doping of Semiconductors Using the Method of Nuclear Reactions. Novosibirsk, Nauka Publ., 1981. 184 p. (in Russian)

2. Mednis I. V. Reference Tables for Neutron-Activation Analyses. Riga, Znanie Publ., 1974. 410 p. (in Russian)

3. Lax B., Neustadter S. F. Transient response of a p-n junction. Journal of Applied Physics, 1984, vol. 25, no. 9, pp. 1148–1154. https://doi.org/10.1063/1.1721830

4. Korshunov F. P., Lastovskii S. B., Markevich V. P., Murin L. I., Bogatyrev Yu. V., Peaker A. R. Defect-impurity complexes with high thermal stability in epi-Si n+-p diodes irradiated with MeV electrons. Vacuum, 2009, vol. 83, pp. S131–S133. https://doi.org/10.1016/j.vacuum.2009.01.044

5. Berman L. S., Lebedev A. A. Сapacity Spectroscopy of Deep Centers in Semiconductors. Leningrad, Nauka Publ., 1981. 176 p. (in Russian).

6. Claybourn M., Newman R. C. Thermal donor formation and the loss of oxygen from solution in silicon heated at 450°C. Applied Physics Letters, 1988, vol. 52, no. 25, pp. 2139–2141. https://doi.org/10.1063/1.99557

7. Astrova E. V. Lebedev A. A. The influence of diode series resistance on deep levels parameters measuring by DLTS-spectroscopy method. Fizika i tekhnika poluprovodnikov= Semiconductors. Physics of the Solid State, 1985, vol. 19, no. 8, pp. 1382–1385 (in Russian).

8. Tatohin E. A., Budanov A. V., Butusov I. Ju., Vasil’eva L. V., Tutov E. A. Capacity spectroscopy of deep levels in case of charge carriers interchange between levels an both allowed energy bands. Vestnik Voronezhskogo gosudarstvennogo universiteta. Seriya Fizika. Matematika = Proceeding of Voronezh State University. Series Physics. Mathematics, 2008, no. 2, pp. 60-70 (in Russian).

9. Korshunov F. P., Marchenko I. G., Zdanovich N. E., Troschinskii V. T. Impact of annealing on recombination centers transformation in irradiated silicon structures. Doklady AN BSSR = Proceedings of the Academy of Sciences of BSSR, 1988, vol. 32, no. 9, pp. 781–783 (in Russian).

10. Korshunov F. P., Zdanovich N. E., Marchenko I. G., Investigation of radiation-thermal defects and their influence on the characteristics of silicon diffused p–n-structures. Vestsі Natsyianal'nai akademіі navuk Belarusі. Seryia fіzіka-matematychnykh navuk = Proceedings of the National Academy of Sciences of Belarus. Physics and Mathematics series, 1998, no. 3, pp. 64–68 (in Russian).