PREPARATION OF Pb(Zr_0.35Ti_0.65)O₃ FILMS ON CONDUCTING OXIDE Ga-DOPED ZnO FILMS FOR TRANSPARENT FERROELECTRIC THIN-FILM TRANSISTORS

ABSTRACT

We have investigated the feasibility of the deposition of ferroelectric PZT films on transparent conducting Ga-doped ZnO (GZO) films, for transparent ferroelectric thin-film transistors. Low resistive and high c-axis oriented GZO films are prepared at the substrate temperature of 250°C using the dc magnetron sputtering method. PZT films are deposited at low substrate temperature and subsequently crystallized by means of the rapid annealing process in a high vacuum to minimize the reaction of PZT with GZO films. Various vacuum-annealing conditions are investigated to get high-quality PZT films, which show single perovskite phase with a random orientation. The optimized PZT/GZO capacitors have somewhat unsaturated P-E hysteresis loops with the values of remanent polarization and coercive field of about 4.5 μC/cm² and 145 kV/cm, respectively.

Keywords:

• Ferroelectric PZT films
• transparent conducting Ga-doped ZnO (GZO)
• vacuum-annealing process
• transparent TFTs