Y. Saya et al., Investigation of nonswitching regions in ferroelectric thin films using scanning force microscopy, JPN J A P 1, 39(6B), 2000, pp. 3799-3803
Nonswitching regions which degrade the electrical properties of ferroelectr
ic thin films were investigated by scanning probe microscopy. An 80-nm-thic
k PbZr0.5Ti0.5O3(001)(PZT) ferroelectric thin film and a YBa2Cu3O7-delta(10
0) bottom electrode were grown on SrTiO3(100) substrates by the pulsed lase
r deposition method. We successfully detected nonswitching regions in the P
ZT thin films by measuring ferroelectric hysteresis loops using a scanning
probe microscope, and the hysteresis loops showed an asymmetric shift towar
d negative remanent polarization. It is suggested that the nonswitching reg
ions originate from dislocations caused by a lattice mismatch between the P
bZr0.5Tr0.5O3(001) and the YBa2Cu3O7-delta(100). The effective thickness of
the nonswitching regions is estimated to be 20 nm from the amount of the s
hift of the hysteresis loops.