Gd-substituted bismuth titanate film capacitors having ferroelectric reliability and large non-volatile charges

• Published in: Physica. B, Condensed matter Condensed matter, 2007-01, Vol.388 (1), p.190-194
• Main Authors: Chon, Uong, Jang, Hyun M., Shin, Nam S., Kim, Jae S., Ahn, Do C., Kim, Yun S., No, Kwangsoo
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Domain structure; hysteresis; Electronics; Exact sciences and technology; Fatigue-free; Ferroelectric; Ferroelectricity and antiferroelectricity; FRAM; Gadolinium-modified bismuth titanate; Integrated circuits; Integrated circuits by function (including memories and processors); Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2006.05.434

Fatigue-free Gd-modified bismuth titanate (Bi 3.15Gd 0.85Ti 3O 12; BGdT) film capacitors having stable charge-retaining characteristics were grown on Pt/TiO 2/SiO 2/Si(1 0 0) substrates using the method of metal-organic sol decomposition. The BGdT film capacitor with a top Pt electrode showed significantly improved values of the remanent polarization (2 P r) and the non-volatile charge as compared to those of the Bi 4− x La x Ti 3O 12 (BLT; x=0.75) film capacitor, currently renowned as a promising candidate for non-volatile memories. The saturated 2 P r value of the BGdT capacitor was 75 μC/cm 2 while it remained essentially constant up to 4.5×10 10 read/write switching cycles at a frequency of 1 MHz. In addition to these, the capacitor demonstrated excellent charge-retention characteristics with its sensing margin of 52 μC/cm 2 and a strong resistance against the imprinting failure.