Kinetics of silicide formation by thin films of V on Si and SiO2 substrates

Abstract

The reaction rate of vacuum-evaporated films of V of the order of I 000 A thick is investigated by MeV He backscattering spectrometry. On substrates of single-crystal Si and for anneal times up to several hours in the temperature range 570--650 ·c, VSi 2 is formed at a linear rate in time. The activation energy of the process is 1.7±0.2 eV. The presence of oxygen in amounts of 10% can significantly decelerate the reaction. On substrates of Si0 2 in the temperature range 730--820 ·c and anneal times of several hours or less, V 3 Si is formed at a square-root rate in time. The activation energy of this process is 2.0±0.2 eV.

Investigating the Formation of MoSe2 and TiSe2 Films from Artificially Layered Precursors

“…In the 1980s and 1990s, the sequence of solid-state reactions between transition metals deposited on silicon substrates was intensely investigated, because transition-metal silicides were desired as low-resistance replacements for heavily doped polysilicon contacts to transistors in integrated circuits. − A focus of this research was understanding the reaction evolution between metals on silicon surfaces, as it was crucial to control the first phase formed in developing the self-aligned silicide or “salicide” process . The first step in the reaction was proposed to be the formation of an amorphous layer at the interface between the metal and silicon, driven by the enthalpy of mixing of the elements .…”

Silicide formation in contacts to Si nanowires

“…In general, for thin V thin films on Si wafers, the phase formation sequence begins with the formation of VSi 2 at temperatures greater than 500°C [13][14][15][16]. However, Krautle et al [14] reported on the effect of O at the interface. They observed that at a clean V/Si interface, VSi 2 would form, but with O present at the interface the first phase to form was V 3 Si.…”

Thin-film synthesis of superconductor-on-insulator A15 vanadium silicide

“…In silicon microelectronics, transition metal silicides are formed by silicidation—the process of annealing metal films deposited on silicon 8 . However, silicidation of V deposited on Si typically forms the Si-rich vanadium silicide phase (VSi 2 ), which is not superconducting, due to the excess supply of available Si during the reaction 18 , 19 . Silicidation of V deposited on thermally-grown SiO 2 can form the A15 phase V 3 Si under the right conditions 18 , 19 , presumably because diffusion of Si out of SiO 2 is slow enough to permit formation of the V-rich phase.…”

“…However, silicidation of V deposited on Si typically forms the Si-rich vanadium silicide phase (VSi 2 ), which is not superconducting, due to the excess supply of available Si during the reaction 18 , 19 . Silicidation of V deposited on thermally-grown SiO 2 can form the A15 phase V 3 Si under the right conditions 18 , 19 , presumably because diffusion of Si out of SiO 2 is slow enough to permit formation of the V-rich phase. However, this process also results in oxygen from the SiO 2 reacting with V to form vanadium oxides that are mixed with V 3 Si in the final structure.…”