Formation of phases in Ti(200 nm)/Cu(200 nm)/Ti(10 nm)/SiO2(370 nm) film composition on monocrystalline silicon(100)

The solid-state reactions in the Ti(200 nm)/Cu(200 nm)/Ti(10 nm)/SiO 2(370 nm) system on the monocrystalline silicon of (100) orientation are investigated. The film system is obtained by electron beam-assisted deposition in 9-10-7 Torr vacuum. Layers of the Ti and Cu are deposited consistently without breaking vacuum. The silicon oxide is grown by the wet oxidation. Specimens of a film system are exposed to series of annealings in the 670-1270 K temperature range for 1 h. For identification of phases, the method of x-ray diffraction is used. Changes of structure of a film system are observed using cross-sectional transmission electron microscopy. Study of morphology of formed phases is carried out by scanning electron microscopy. Electrical resistance is measured by four-probe method. As revealed after annealing at 670 K for 1 h, Cu3Ti and Cu4Ti intermetallics are formed. The formation of first copper suicide Cu 15Si4 phase is observed after annealing at 1070 K for 1 h. Annealing at 1270 K is accompanied by formation of ternary CuTiSi compound.