Neutron transmutation doping of n-type material was carried out by irradiating the samples with thermal neutrons in order to create P. Positron lifetime measurements were then performed, and the evolution of the introduced defects was studied by thermal annealing. Annealing out of the divacancy was detected between 200 and 350C. At about 700C, large vacancy clusters (containing about 8 vacancies) formed. All the defects were annealed out above 800C.

Defects in Neutron Transmutation Doped Silicon Studied by Positron Annihilation Lifetime Measurements M.Coeck, N.Balcaen, T.Van Hoecke, B.Van Waeyenberge, D.Segers, C.Dauwe, C.Laermans: Journal of Applied Physics, 2000, 87[8], 3674-7