AVS 52nd International Symposium
    Nanometer-Scale Science and Technology Wednesday Sessions
       Session NS-WeA

Paper NS-WeA10
Patterning of Well-Ordered PZT Nanodot Arrays using Silicon Nitride Shadow Mask

Wednesday, November 2, 2005, 5:00 pm, Room 210

Session: Nanopatterning and Manipulation
Presenter: H.-J. Shin, Seoul National University, Korea
Authors: H.-J. Shin, Seoul National University, Korea
J.H. Choi, Seoul National University, Korea
H. Yang, Seoul National University, Korea
Y.D. Park, Seoul National University, Korea
Y. Kuk, Seoul National University, Korea
C.J. Kang, Myungji University, Korea
Correspondent: Click to Email
We patterned well ordered arrays of Pb(Zr@sub 0.2@Ti@sub 0.8@)O@sub 3@ nanodots on a SrRuO@sub 3@/SrTiO@sub 3@ substrate by pulsed laser deposition. A silicon nitride shadow mask with ordered holes was used for patterning of PZT arrays. This method have an advantage that deposition could be done at high temperature, which could be applicable to in situ deposition avoiding any possible contamination in dot formation. In addition, we could change the shape or size of the patterns if necessary. The SrRuO@sub 3@ bottom electrode and PZT nanodots were deposited at 760 @super o@C and 660 @super o@C, respectively. The lateral size of the dot was about 120 nm and the height was about 15 ~ 20 nm. The inter-dot distance of PZT dot arrays was about 200 nm, exactly the same as the pore-to-pore distance of the shadow mask. Each dot was fully arranged and well isolated, having dome shape after deposition. The local switching of a single dot was examined using piezoresponce force microcopy. We could observe that the absolute piezoresponse value of positively polarized dot is 28.3 % larger than that of negatively polarized background, and there weren't any noticeable inhomogeneity such as an inversion of center region after polarization. The polarized states were maintained at 61.3 % of initial value after ~ 20 min, which almost relaxed suddenly to noise level after 30 min. A sudden drop of polarization implies that the relaxation is mainly related to the nucleation stages of domain reversal in our case.