Fabrication of Self-Assembled Au Nanodots and Their Applications to Ferroelectric Nanocapacitors

We report on the fabrication of self-assembled Au nanodots by high temperature annealing of Au thin films on SiO 2 , Pb(Zr,Ti)O 3 (PZT) thin films and PbTiO 3 nanodots and on their application to ferroelectric nanocapacitors as top electrodes. When Au films 5–20 nm thick were annealed at 500–900 °C, aggregation of Au thin films occurred, and isolated Au nanodots were formed. By annealing Au films 10 nm-thick at 500 °C for 10 min in air, Au nanodots with average lateral sizes of 82 and 122 nm were obtained on SiO 2 and PZT, respectively. We have successfully measured piezoelectric hysteresis loops and current–voltage curves of nanocapacitors with Au nanodots with areas of (1.8–7.3)×10 4 nm 2 as the top electrode using a scanning probe microscope. Au nanodots were also fabricated on PbTiO 3 nanodots, demonstrating the possibility of fabricating ferroelectric nanocapacitors with self-assembled top electrodes and ferroelectrics.