LOW TEMPERATURE DIRECT CRYSTALLIZATION OF SrBi2(Ta1-xNbx)2O9 THIN FILMS BY THERMAL METALORGANIC CHEMICAL VAPOR DEPOSITION AND THEIR PROPERTIES

• Published in: Jpn.J.Appl.Phys ,Part 1. Vol. 40, no. 5A, pp. 3337-3342. 2001 Vol. 40; no. 5A; pp. 3337 - 3342
• Main Authors: Mitsuya, M, Nukaga, N, Saito, K, Osada, M, Funakubo, H
• Format: Journal Article
• Language: English
• Published: 01.01.2001
• ISSN: 0021-4922
• DOI: 10.1143/jjap.40.3337

Directly crystallized SrBi2(Ta1-xNbx)2O9 (SBTN) films were deposited on (111) Pt/Ti/SiO2/Si substrates at 585-670 C by thermal MOCVD. The crystalline SBTN film was directly deposited at 670 C irrespective of the deposition rate, but its leakage current decreased when the deposition rate decreased from 5.0 to 2.1 nm/min. When the deposition rate was below 2.1 nm/min, an SBTN film with large ferroelectricity was deposited even at 585 C, and strong (103) orientation was ascertained by an X-ray reciprocal space mapping method. This orientation is considered to locally epitaxially occur on a (111)-oriented Pt substrate. Twice the remanent polarization (2Pr) and twice the coercive field (2Ec) of the film deposited at 585 C were 12.2 mu C/cm2 and 160 kV/cm, resp. When the deposition temperature increased, the film became randomly oriented, which was in response to the orientation change in the Pt substrate from single (111) to a mixed orientation of (111) and (100) orientations by heating before starting the film deposition. 2Pr and 2Ec of the film deposited at 670 C increased to 23.8 mu C/cm2 and 190 kV/cm, resp. 22 refs.