Fabrication of Pb(Zr, Ti)O3 thin films by liquid source misted chemical deposition method equipped with a mist-droplet size controller

The liquid source misted chemical deposition (LSMCD) method has attracted much attention for fabricating integrated ferroelectric random access memories (FeRAMs). We have developed a new atomizer and an advanced refiner with ultrasonic vibration which made possible the efficient generation of mist droplets with a diameter of 0.2 mum. In a conventional system, the droplet-size distributions measured by a particle counter were significantly changed by changing the carrier gas flow rate. However, by applying vibration to the refiner, the range of the carrier gas flow rate in which the droplets with sizes of less than 0.2 mum were the primary components has been expanded. The PZT thin films were fabricated using this refined mist. The films fabricated with vibration showed well saturated hysteresis loops and higher 2 P-r than that fabricated without vibration. The 2 P-r and 2 E-c of the films were 62 muC/cm(2) and 120 kV/cm, respectively. Moreover, we fabricated a PZT film as thin as 55 nm that exhibited ferroelectric properties by LSMCD with vibration.