Effect of nitrogen gas on preparation of Ti–Al–N thin films by pulsed laser ablation

The effect of ambient N2gas on the preparation of Ti0.9Al0.1N TAN.thin films for ferroelectric capacitors by pulsed laser ablation PLA.using ArF and KrF excimer lasers was explored. The TAN films were prepared on 100.Si substrates heated at 6208C in various N2 pressures ranging from vacuum to 130 Pa. The TAN crystal growth was found to be influenced by the content of unintentionally incorporated O which was found to be controlled by the introduction of N2 gas into the deposition chamber. The O content for films prepared by KrF was found to be smaller than that for films prepared by ArF. This was due to the smaller optical absorption cross-section of KrF excimer laser for residual O2or H2O molecules in the chamber andror the higher deposition rate. The TAN film prepared by KrF excimer laser was found to be nearly epitaxial Si with a cube-on-cube crystallographic orientation. q1998 Elsevier Science B.V