Target for a Pb(Zr,Ti)O3 Thin Film Deposited at a Low Temperature Using a Quasi-Metallic Mode of Reactive Sputtering

Using a (ZrTi+PbO) composite target in the quasi-metallic mode reactive sputtering (QMMRS) system, perovskite Pb(Zr,Ti)O3 films were deposited at a rate of 8 nm/min at the substrate temperature of 450°C. X-ray diffraction analysis of a film deposited at a substrate temperature of 450°C and with O2/Ar = 2.1%, using a powder target with a stoichiometric composition of PZT of Pb:Ti:Zr =1:0.5:0.5, revealed that it had almost the same crystal structure as that of a film produced using a (ZrTi+30%PbO) composite target. The deposition rate was 3 nm/min. To fabricate PZT thin films at a high deposition rate using QMMRS, a (Pb+ZrO2+Ti) mixture target was prepared. Although it is possible to produce a film with a high deposition rate at 450°C, perovskite PZT film could not be obtained. This may be due to differences in sputtering yield for Zr and ZrO2 atoms or in the heat of formation of PbO and ZrO2 molecules. A new solid target that is free from the problems associated with the (Pb+ZrO2+Ti) mixture target is currently being developed.