Point-defect properties in ion-irradiated Si were investigated using in situ grazing incidence diffuse X-ray scattering. Bombardment with 4.5keV He at 100K and 3MeV electrons at 6K led to the production of Frenkel pairs. These defects were characterized by close-pair configurations and by relaxation volumes of vacancies and interstitials that have nearly the same magnitude, but opposite sign. Thermally activated motion of interstitial atoms occurred above about 150K, while that for vacancies occurred above about 175K. The motion of interstitials below 150 K during electron irradiation was shown to be induced by electronic excitation, and it was negligible for ion irradiations. Similar results were observed for irradiation with 20keV Ga and 1MeV Ar, although the defects were already clustered upon bombardment at 100K. Correlation distances between vacancies and interstitials in cascades were obtained.

Grazing Incidence Diffuse X-Ray Scattering Investigation of the Properties of Irradiation-Induced Point Defects in Silicon. P.Partyka, Y.Zhong, K.Nordlund, R.S.Averback, I.M.Robinson, P.Ehrhart: Physical Review B, 2001, 64[23], 235207 (8pp)