Journal of Radiation Safety and Measurement

Journal of Radiation Safety and Measurement

Doppler broadening of positron annihilation on gamma, neutron, and electron-irradiated N- and P-type Silicon wafers

Document Type : Original Article

Authors
Masumeh Arbabi-Baluchestan
Ali Akbar Mehmandoost-Khajeh-Dad
Physics Department, University of Sistan and Baluchestan, Iran
10.22052/rsm.2023.252969.1025
Abstract
In this research, Doppler broadening measurements of positron annihilation have been done on N- and P-type irradiated silicon wafers which have widely used in the electronics industry. The wafers were irradiated by 10-MeV electrons beam (30 kGy), 60Co gamma rays (175 kG) and thermal neutrons (~ 0.038 Gy). The radioactive isotope of 22Na with an activity of about 7µCi, which is enclosed between two thin polymer layers with a thickness of 7µm were used as a positron source. A conventional setup using an HPGe semiconductor detector in coincidence with a NaI(Tl) scintillator detector. The results of this research indicate the presence of visible defects in the electron irradiated samples.
Keywords
Positron Annihilation Spectroscopy
Doppler Broadening
N-type Silicon
P-type Silicon
Irradiated Silicon
  1. R. Krause-Rehberg, H. S. Leipner. Positron Annihilation in Semiconductors: Defect Studies. Springer-Verlag, Berlin, Heidelberg, New York, 1999.
  2. I. Prozheev, F. Mehnke, T. Wernicke, M. Kneissl, F. Tuomisto. Electrical compensation and cation vacancies in Al rich Si-doped AlGaN. Appl. Phys. Letters 117 (14) (2020)142103-142105.
  3. G. Brauer, W. Anwand, W. Skorupa, A. G. Revesz, J. Kuriplach. Characterization of the SiO2/Si interface by positron annihilation spectroscopy. Phys. Rev. B 66 (19) (2002) 195331.
  4. E. Tayebfard, A. A. Mehmandoost-Khajeh-Dad, M. Khaghani, M. Jafarzadeh-Khatibani, A. M. Poorsaleh. Stability of a positron lifetime measurement system, and investigation the types and concentrations of defects induced by10 MeV electron irradiation on n-and p-types Si. Iran. J. Phys. Res.15 (1) (2015) 34-41.
  5. F. A. Selim. Positron annihilation spectroscopy of defects in nuclear and irradiated materials- a review. Mater. Characterization 174 (1) (2021) 110952.
  6. E. Nascimento, O. Helene, V. R. Vanin, M. Moralees. Study of the Doppler Broadening of positrin annihilation radiation in silicon. Brazilian J. Phys .35 (3B) (2005) 782-784.
  7. M. Hakala, M.J. Puska, R. M. Nieminen. Momentum distributions of electron-positron pairs annihilating at vacancy clusters in Si. Phys. Rev. B 57 (13) (1998) 7621-7627.
  8. V. Avalos, S. Dannefaer. Positron-annihilation investigation of vacancy agglomeration in electron-irradiated float-zone Silicon. Phys. Rev. B 54 (3) (1996) 1724-1728.
  9. R. S. Brusa, C. Macchi, S. Mariazzi, G. P. Karwasz, W. Egger, P. Sperr, G. Kögel. Decoration of buried surfaces in Si detected by positron annihilation spectroscopy. Appl. Phys. Lett.88 (1) (2006) 011920.
  10. A. A. Mehmandoost-Khajeh-Dad, Introduction to Positron Annihilation Spectroscopy. University of Sistan and Baluchestan Publication, Zahedan, 2018.
  11. S. Szpala, P. Asoka-Kumar, B. Nielsen, J. P. Peng, S. Hayakawa, K. G. Lynn, H. J. Gossmann. Defect identification using the core-electron contribution in Doppler-broadening spectroscopy of positron-annihilation radiation. Phys. Rev. B 54 (7) (1996) 4722-4731.‏