Performance and reliability of low-temperature processed SrBi2Ta2O9 capacitors for FeRAM applications

• Published in: Journal of the Electrochemical Society 2004, Vol.151 (5), p.F113-F117
• Main Authors: OH, Sang-Hyun, KEUM HWAN NOH, SEAUNG SUK LEE, KANG, Hee-Bok, YOUNG HO YANG, LEE, Kye-Nam, HONG, Suk-Kyoung, PARK, Young-Jin
• Format: Article
• Language: English
• Subjects: Applied sciences; Capacitors. Resistors. Filters; Electrical engineering. Electrical power engineering; Exact sciences and technology; Various equipment and components
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1.1687429

Low-temperature processed SrBi2Ta2O9 (SBT) capacitors were tested as the ferroelectric memory cells of fully functional ferroelectric random access memory (FeRAM) devices. The 100 nm thick SBT films were deposited by the spin-on coating technique using a metallorganic decomposition source and crystallized by rapid thermal annealing at 700DGC for 1 min followed by a furnace annealing at 650DGC for 1 h under oxygen atmosphere, considered a low thermal budget process. The fabricated Pt/SBT/Pt capacitors showed reasonable ferroelectric performances with a DeltaP (switching polarization-nonswitching polarization) of approximately 10 mX/cm 2 after the full process integration. The FeRAM chip-level reliability analysis showed that the major reason for the function failure was from the opposite state retention characteristics due mainly to the small DeltaP values. A 10-year guaranteed lifetime can be achieved when the operation voltage is higher than approximately 4 V at the test condition of 85DGC operation and 125DGC storage.