The formation of new donors in Czochralski-type material during heat treatment at 600 to 700C were considered. These thermal donors involved several families of centers. The components which predominated at the 2 ends of the heat treatment range differed markedly. At lower temperatures, very shallow donor centers and thermal double donors were the main components. At high temperatures, deep donors were of greatest importance.

V.V.Emtsev, G.A.Oganesyan, K.Schmalz: Solid State Phenomena, 1996, 47-48, 259-66