It was recalled that the generation of low-temperature thermal donors was sensitive to the cooling rate (from the annealing temperature to room-temperature) and to the nature of the ambient (air or vacuum). This effect was most pronounced in the case of annealing at 500C. It was noticeable at 480C, but was essentially undetectable at 450C. The results could be satisfactorily interpreted as being due to a thermal donor generation that was enhanced in the presence of Si self-interstitials. The latter were emitted by thermal donors and were then absorbed by sinks; especially the sample surface and grown-in micro-defects (vacancy voids). Upon annealing in a vacuum, the surface acted as the main sink. If annealing was performed in air, this sink was passivated as a result of oxidation and/or contamination; with voids becoming the main sinks. As a result, the Sii concentration increased substantially and the generation rate was enhanced. Rapid cooling caused partial passivation of the voids (as a result of their becoming decorated with rapidly diffusing impurities) and an additional enhancement of the generation rate. The rate curves which were predicted by using this model agreed well with experiment.

Generation of Thermal Donors in Silicon: Effect of Self-Interstitials. V.V.Voronkov, G.I.Voronkova, A.V.Batunina, V.N.Golovina, M.G.Milvidskii, A.S.Gulyaeva, N.B.Tyurina, L.V.Arapkina: Fizika Tverdogo Tela, 2000, 42[11], 1969-75 (Physics of the Solid State, 2000, 42[11], 2022-9)