Reduction of crystallization temperature of the Aurivillius phase in Nd-doped SrBi2Ta2O9 thin films via substrate bias

Nd-doped SrBi2Ta2O9 films were sputtered on Pt/Ta/SiO2/Si substrates under various substrate biases. The radio frequency bias results in the reduction of the Aurivillius phase crystallization temperature. At 48 W, the crystallization temperature of film is lowered at a magnitude of about 80 °C. When the bias further increases, Aurivillius phase formation is suppressed due to too deficient Bi in film. The film deposited at 48 W after annealing at 670 °C shows ferroelectric characteristics. The remnant polarization of the films increases as the annealing temperature is increased.