Specific features of formation of radiation defects in the silicon layer in “silicon-on-insulator” structures

Abstract

Specific features of formation of radiation defects in thin silicon layer of silicon-on-insulator (SOI) structures have been studied. It is shown that there are differences between variations in the structural and electrical properties of the thin silicon layer and those in bulk silicon crystals (with similar electrical characteristics) subjected to the same radiation effect. It is established that the embedded insulator in the SOI structure represents a barrier for motion of radiation-induced intrinsic interstitial silicon atoms, which brings about an increase in the dose of bombarding ions, which leads to the loss of single-crystallinity of the silicon layer in a SOI structure. It is shown that γ-ray irradiation with doses unaffecting the electrical conductivity of bulk silicon crystals appreciably affects the conductivity of the silicon layer in the SOI structures. In addition, variation in the conductivity of silicon layer is related to variation in the density of surface states at the interface between the silicon layer and the built-in insulator, rather than to generation of conventional radiation-induced structural defects in silicon.