Preparation of Pb(Zr_x, Ti_1-x)O₃ Thin Films by Source Gas Pulse-Introduced Metalorganic Chemical Vapor Deposition

Abstract

We prepared Pb(Zr x , Ti1-x )O3 [PZT] thin films on (111)Pt/Ti/SiO2/Si substrates at 620°C by metalorganic chemical vapor deposition (MOCVD). PZT [Zr/(Zr+Ti)=0.68] thin films of different thicknesses prepared by the conventional continuous source gas introduction MOCVD (continuous-MOCVD) and by pulsed gas introduction MOCVD (pulse-MOCVD) were compared to investigate the growth mechanism of these films. Stoichiometric PZT films were obtained for a wider range of Pb source input gas flow rates under fixed Zr and Ti sources for pulse-MOCVD compared with that for continuous-MOCVD. Highly (111)-oriented films were obtained for pulse-MOCVD regardless of their thickness, while the (111)-orientation decreased with film thickness for continuous-MOCVD. This suggests that the orientation homogeneity along the film thickness is higher for pulse-MOCVD films than for continuous-MOCVD films. The surface roughness of the pulse-MOCVD films was smaller than that of the continuous-MOCVD films and this result corresponds to the decrease of the leakage current density of the film. Well-saturated hysteresis loops with good square shapes were obtained, and the remanent polarization (P r) and the coercive field (E c) values of 100-nm-thick films prepared by pulse-MOCVD were 37 µC/cm2 and 82 kV/cm, respectively.

Self-organized one-axis-oriented PZT films with nano-domain structure

“…When the deposition rate was 0.12 mm/h, 10 times lower than in the present study, the PZT films tended to have a (111) orientation because their grains were locally epitaxially grown on (111)Pt grains, (111)PZT//(111)Pt, due to its similar lattice parameters [10]. However, this local epitaxial growth was difficult to achieve when the deposition rate increased.…”

Gas‐Pulsed CVD for Film Growth in the CuNiN System

“…The perovskite structure was fabricated by a sequential supply of Pb for the A-sites and of Zn and Nb for the B-sites. The interruption between the precursor pulses was 5 s. [6][7][8] This work employs, for the first time, purging with reactive gases between the CVD pulses and demonstrates the effect of the gas pulsing on the deposition process. For a demonstration of the design concept with a host material and the introduction of another component into the crystal structure, Cu 3 N was chosen as host and Ni was chosen as the other component.…”

Single-phase Pb(Zn1/3Nb2/3)O3 thin films grown by metalorganic chemical vapor deposition: Effects of growth sequence and substrates

“…Fig. 1(b) represents an advanced growth sequence for high quality films called pulsed-MOCVD [9,10] in which the mixture gas is introduced in pulses with a brief time interval between each pulse.…”