Positron trapping rates and their temperature dependencies in electron-irradiated silicon

Journal Article · Fri Dec 15 04:00:00 EST 1989 · Physical Review (Section) B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.40.11764· OSTI ID:7021173

Mascher, P; Dannefaer, S; Kerr, D ^[1]

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1. Department of Physics, University of Winnipeg, Winnipeg, Manitoba, Canada R3B2E9 (CA)

Defects created by 2-MeV electron irradiation of Czochralski-grown silicon have been investigated with use of positron-lifetime spectroscopy and results have been correlated with EPR and ir data. The trapping rate for the positrons was smallest for the neutral divacancy where a concentration of {similar to}10{sup 17} cm{sup {minus}3} gave rise to a trapping rate of 1 ns{sup {minus}1}. For the singly negative divacancy the trapping rate was increased at 300 K by a factor of about 3.5 and for the doubly negative divacancy a further increase by a factor of 2 was found. Isochronal annealing showed that the neutral divacancy annealed at only 150 {degree}C, while the charged states annealed in a broad temperature range starting at 230{degree}C. The monovacancy component found in some of the samples could be identified as being due to divacancy-oxygen complexes. Measurements in thermal equilibrium between 30 K and room temperature showed that shallow positron traps became activated at low temperatures. Oxygen vacancy pairs ({ital A} centers) are concluded to be the defects acting as shallow traps and yielded a lifetime of 225 ps, very close to the bulk lifetime of silicon. The trapping cross section of the charged defects varied with temperature as {ital T}{sup {minus}{ital n}}, with 2{lt}{ital n}{lt}3.

• OSTI ID: 7021173
• Journal Information: Physical Review (Section) B: Condensed Matter; (USA), Journal Name: Physical Review (Section) B: Condensed Matter; (USA) Vol. 40:17; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360605* -- Materials-- Radiation Effects
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
COLLISIONS
CRYSTAL DEFECTS
CRYSTAL GROWTH METHODS
CRYSTAL STRUCTURE
CZOCHRALSKI METHOD
ELECTRON COLLISIONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY RANGE
FERMIONS
LEPTONS
MEDIUM TEMPERATURE
MEV RANGE
MEV RANGE 01-10
PHYSICAL RADIATION EFFECTS
POSITRONS
RADIATION EFFECTS
SEMIMETALS
SILICON
TEMPERATURE DEPENDENCE
TRAPPING