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

Journal Article · Fri Dec 15 00:00:00 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), Vol. 40:17; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

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