Laser reactive ablation deposition of TiC films

Abstract

Titanium carbide films were deposited on silicon wafers by XeCl (308 nm) excimer laser ablation of titanium in low pressure (10 −6–10 −1 mbar) methane atmosphere. Series of 10000 pulses at the repetition rate of 8 Hz were directed to the target surface. The fluence was set at 4.5 and 5.5 J/cm 2. Pulse duration was about 30 ns. The deposited films were charcterized by different techniques (Rutherford backscattering spectrometry, X-ray diffractometry and scanning electron microscopy). Results show that at both fluences and at pressures below ≈ 10 −5 mbar the deposited films are mainly formed of metallic titanium. In the range 10 −3–10 −1 mbar, at the fluence of 4.5 J/cm 2, the deposits are formed of titanium carbide (TiC) with only traces of oxides. At the fluence of 5.5 J/cm 2 the amount of ablated material is too large to undergo complete reaction and mostly metallic titanium is deposited.