Ultra-rapid cooling in the millisecond timescale for the enhancement of polarization properties in Al:HfO 2 thin films using flash lamp annealing

Superior ferroelectric properties of Al-doped HfO 2 (HAO) thin films are demonstrated using flash lamp annealing (FLA). This annealing approach is a low-thermal-budget treatment that features short annealing times at the millisecond timescale. We first clarified the annealing conditions with respect to optimum ferroelectricity. The results show that 5-millisecond annealing at 1000 °C is sufficient for adequate crystallization, achieving a high 2P r value of 17.3 μ C cm −2 . By adjusting the cooling rate on the millisecond timescale during crystallization annealing, a high cooling rate of 182 °C ms −1 exhibited a superior 2P r value of 16.6 μ C cm −2 , in contrast to a slow cooling rate of 12 °C ms −1 , which yielded a 2P r value of 10.2 μ C cm −2 . The results indicate that the control of the cooling rate is crucial for achieving an optimum 2P r value, illustrating the potential of FLA for forming high-quality ferroelectric thin films.