Low temperature CVD of Pb(Zr,Ti)O-3 using Pb(tmhd)(2), Zr(dmae)(4), and Ti(dmae)4

Abstract

Pb(Zr,Ti)O-3 (PZT) thin films were deposited at low temperatures by direct liquid injection metallorganic chemical vapor deposition (MOCVD) process using Pb 2,2,6,6,-tetramethyl 3,5-heptanedionate (tmhd)(2), Zr dimethyl aminoethoxide (dmae)(4), and Ti(dmae)(4). Zr(dmae)(4), and Ti(dmae)(4) were found to be less sensitive to moisture and air but their dissociation temperature was about the same as alkoxides. Two separate solution of Pb(tmhd)(2) and of Zr(dmae)(4) and Ti(dmae)(4) were used and the growth rate of PZT films was around 11 nm/min at substrate temperatures of 380-440degreesC. Because decomposition temperatures of Pb(tmhd)(2), Ti(dmae)(4), and Zr(dmae)(4) are in the same range, control of the film composition was comparatively easy. PZT films deposited below 450degreesC had negligible carbon and nitrogen content. Pure perovskite PZT films were obtained at temperatures as low as 440degreesC on Pt/Ti/SiO2/Si substrate and 425degreesC on Ir/Ti/SiO2/Si substrate, respectively. The remanant polarization of PZT films prepared at 425degreesC on Ir/Ti/SiO2/Si substrate was 21 muC/cm(2) and the leakage current density at 100 kV/cm was less than 10(-6) A/cm(2). (C) 2003 The Electrochemical Society.