Micropatterning of SrBi 2 Ta 2 O 9 Ferroelectric Thin Films Using a Selective Deposition Technique Combined with Patterned Self-Assembled Monolayers and Liquid-Source Misted Chemical Deposition

• Published in: Japanese Journal of Applied Physics 2005-04, Vol.44 (4R), p.1897
• Main Authors: Takakuwa, Atsushi, Ishida, Masaya, Shimoda, Tatsuya
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.44.1897

We demonstrated a novel patterning method using a selective deposition technique of ferroelectric thin films without etching. Self-assembled monolayers (SAMs) of 1H,1H,2H,2H-perfluorodecyltriethoxysilane [CF 3 (CF 2 ) 7 CH 2 CH 2 Si(OC 2 H 5 ) 3 ; FAS] were patterned on Pt/SiO 2 /Si substrates. The patterned SAMs on these surfaces defined the selective area on which the liquid-source misted chemical deposition (LSMCD) of SrBi 2 Ta 2 O 9 (SBT) was performed. Pt top electrodes were then sputter-deposited on the patterned SBT films by the liftoff method. The remanent polarization ( P r ) of the obtained SBT films was 7.5 µC/cm 2 with good squareness of the hysteresis loops for 50 µm×50 µm square capacitors. By this method, we succeeded in fabricating uniform lines of ferroelectric thin films of 0.5 µm width. These results show that a selective deposition technique is promising for realizing high-density ferroelectric random access memories (FeRAMs).