Article contents
Grown-in vacancy-type defects in poly- and single crystalline silicon investigated by positron annihilation
Published online by Cambridge University Press: 24 January 2007
Abstract
Positron annihilation was used to characterize vacancy-type defects in two types of polycrystalline Si grown at temperatures above ~800 °C by chemical vapour deposition. The majority of vacancies (80%) consisted of monovacancies, and their thermal stability indicated them to be trapped at grain boundaries or at dislocations. Annealing above 500 °C caused a significant reduction in the monovacancy concentration, and an increase in divacancy concentration. Divacancies started to anneal above 1200 °C. Measurements between 8 and 293 K indicated that vacancies were neutral before as well as after annealing at 1380 °C. Fz-grown Si from one of these materials contained vacancy clusters with an average size of six to ten vacancies which persisted to 1380 °C. The cluster concentration corresponded to a monovacancy concentration of 1015 to 1016 cm−3, which is at least one order of magnitude larger than estimates based on voids [R. Falster, V.V. Voronko, F. Quast, Phys. Status Solidi B 222, 219 (2000)].
- Type
- Research Article
- Information
- The European Physical Journal - Applied Physics , Volume 37 , Issue 2 , February 2007 , pp. 213 - 218
- Copyright
- © EDP Sciences, 2007
References
- 6
- Cited by