Investigation of the mechanism of titanium silicide reaction using ion-beam-assisted deposition

Abstract

In order to promote the formation of C54 TiSi2, the suppression of C49 TiSi2 formation by ion-beam-assisted deposition of Ti film was investigated. When the Ti film was deposited without ion bombardment, C49 TiSi2 was formed at 600 °C. In contrast, in the case where the Ti film was deposited with concurrent ion bombardment, TiSi formation occurred at the same temperature. The formation of TiSi was attributed to the enhancement of both Si and Ti diffusion below 600 °C, due to grain refinement induced by Ar-ion-beam bombardment. By the adoption of ion-beam-assisted deposition to the conventional Ti silicide process, the gate line width dependence of C54 TiSi2 formation can be eliminated, since this formation is achieved via a direct interfacial reaction between TiSi and Si, and not a conversion of C49 TiSi2.