Improvement in homogeneity and ferroelectric property of mist deposition derived Pb(Zr,Ti)O3 thin films by substrate surface treatment

Pt/TiO2/SiO2/Si substrate UV surface treatment was carried out with O-3 or N-2/O-2 atmosphere before film deposition to improve the homogeneity of mist deposition (MD)-derived Pb(Zr, Ti)O-3 (PZT) films. The effect of the surface treatment was determined by measuring the contact angle of the distilled water on Pt substrates. The largest improvement in wettability was achieved in the N-2/O-2 atmosphere at the O-2 partial pressure of approximately 10%. The macroscopic homogeneity of PZT films deposited onto the surface-treated Pt substrates was dramatically improved with a decrease in the contact angle. Although the contact angle of 0degrees was achieved by over 5 min UV treatment in any atmosphere, the P-E hysteresis properties and J-E characteristics were further improved with treatment time, even after the contact angle of 0degrees was reached. The improvement in electrical properties corresponded closely to the improvement in microscopic surface roughness. The PZT film deposited onto UV/N-2-treated Pt substrates for 30 min showed the two fold remanent polarization (2P(r)) of 52 muC/cm(2), while the PZT film on the 5-min-treated substrate showed 44 muC/cm(2).