TWO STEP REACTIVE MAGNETRON SPUTTERING OF BLT THIN FILMS

ABSTRACT

Well crystallized BLT thin films were deposited by RF magnetron sputtering using a home made target of Aurivillius phase Bi_3.25La_0.75Ti₃O₁₂ (BLT_0,75). RF sputtering experiments were performed at room temperature with an argon/oxygen mixture, in a pressure range of 20–50 mTorr. Optimisation of the plasma parameters, namely deposition pressure, RF power and oxygen content in the gas phase, allows obtaining BLT films with a chemical composition close to Bi_3.25La_0.75Ti₃O₁₂. After ex-situ annealing under oxygen atmosphere at 650 °C, BLT deposited on Pt/TiO₂/SiO₂/Si (multilayer) substrates exhibits well crystallized films with granular morphology. A two step deposition process appeared to be necessary in order to reach satisfying dielectric properties. The effect of the plasma parameters on the chemical composition and electrical properties are presented and discussed.

Notes

^a ,

^b ,

^c ,

^d : the corresponding XRD patterns are shown in Figure 1 a to 1 d, respectively