Application of titanium silicide as an interconnect in deep submicron integrated chip manufacturing

Abstract

Although titanium silicide is thermally stable at high temperatures in a face centred orthorhombic structure (C54-TiSi2), there exists a meta-stable phase at lower temperatures with a base centred orthorhombic structure (C49-TiSi2) which first forms. The final C54 phase is desired over the C49 phase because it is thermally stable and has a low electrical resistivity. Demand for faster electronics led to higher circuit density in MOS devices and smaller feature sizes. It was then discovered that the phase transformation of titanium silicide from C49 phase to C54 phase is area-dependent. The kinetics of the phase transformation and properties of the resulting titanium silicide from different processing techniques are hence studied in the present investigation. Both new and improved processing techniques based on current manufacturing tools are investigated and integrated into an existing manufacturing process, while newer novel techniques are explored and investigated.