藤沢 浩訓

Abstract Superior ferroelectric properties of Al-doped HfO₂ (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 μC 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 μC cm⁻², in contrast to a slow cooling rate of 12 °C ms⁻¹, which yielded a 2P_r value of 10.2 μC 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.