PZT 박막 제조를 위한 Pb 전구체 합성 및 분석

Abstract

A new series of Pb precursors for PZT materials were successfully synthesized. For Pb4+ precursors, chemically inert phenyl ligands in Ph4Pb were partially replaced by β-ketonate and silylamide ligand (1-3) to endow chemical reactivities toward vapor phase deposition processes. As for the Pb2+ precursors, aminoalcohols were chosen for ligand to synthesize reactive and volatile lead precursor in place of alcohol or β- ketonate ligands. In contrast to traditional synthetic routes from Pbbtsa2 to lead(II) aminoalcoholate, Pb2+ precursors 4-6 were synthesized using NaOH, aminoalcohol, and ethanol. Precursors were purified by recrystallization method in hexane (1-3) or solubility difference between products in organic solvents (4-6). Precursors 1-6 were characterized by FT-IR, 1H-NMR, and TGA analyses and precursors 2 and 3 exhibited volatile properties, showing a possibility for MOCVD applications. The monomeric structures of 2 and 3 were identified by single-crystal X-ray crystallography method. Mixing precursors with 0.5 equivalent of Ti(OiPr)4 and 0.5 equivalent of Zr(OPr)4 in 1-butanol (1-3) or 2-methoxyethanol (4-6), stable PZT solution were made without acidic or basic additives. After spin-coating, thermal decomposition and sintering processes, PZT films were fabricated and their phase conversion to perovskite phases was monitored by XRD method.