Metallorganic chemical vapor deposition of Pb(Zr, Ti)O-3 films using a single mixture of metallorganic precursors

Pb(tmhd)(2), Ti(O'Pr)(2)(tmhd)(2), and Zr-2(O'Pr)(6)(tmhd)(2) were used as metallorganic chemical vapor deposition (MOCVD) sources for Pb(Zr, Ti)O-3 ( PZT) films. Thermal properties of PZT precursors and the stability of precu rsor solution were evaluated. A mixed solution of three precursors in tetra hydrofuran (THF) solvent showed a time-dependent degradation due to a ligan d exchange reaction between Pb(tmhd)(2) and Zr-2(O'Pr)(6)(tmhd)(2). Growth characteristics of PZT thin films deposited on a (111)Pt/TiO2/SiO2/Si subst rate by MOCVD have been investigated. A direct liquid injection technique u sing a flash-vaporized metallorganic precursor solution was employed for th e film deposition. The incorporation rates of constituent metals in the PZT film are strongly dependent on the substrate temperature and precursor mol ar ratios in the precursor solution. As the substrate temperature was incre ased, the incorporation rate of Ph and Ti increased and that of Zr remained constant. As the ratio of Zr/Ti in the PZT precursor solution was increase d, Pb/(Zr + Ti) decreased and Zr/(Zr + Ti) increased. Pure perovskite films were obtained at temperatures between 470 and 530 degreesC when a solution with an atomic ratio of Pb:Zr:Ti = 1.1:0.4:0.6 was used. (C) 2001 The Elec trochemical Society.