Table1_Large remnant polarization and great reliability characteristics in W/HZO/W ferroelectric capacitors.DOCX

In this work, the effect of rapid thermal annealing (RTA) temperature on the ferroelectric polarization in zirconium-doped hafnium oxide (HZO) was studied. To maximize remnant polarization (2Pr), in-plane tensile stress was induced by tungsten electrodes under optimal RTA temperatures. We observed an increase in 2Pr with RTA temperature, likely due to an increased proportion of the polar ferroelectric phase in HZO. The HZO capacitors annealed at 400°C did not exhibit any ferroelectric behavior, whereas the HZO capacitors annealed at 800°C became highly leaky and shorted for voltages above 1 V. On the other hand, annealing at 700 °C produced HZO capacitors with a record-high 2Pr of ∼ 64 μC cm−2 at a relatively high frequency of 111 kHz. These ferroelectric capacitors have also demonstrated impressive endurance and retention characteristics, which will greatly benefit neuromorphic computing applications.

本研究探讨了快速热退火（rapid thermal annealing, RTA）温度对掺锆氧化铪（zirconium-doped hafnium oxide, HZO）中铁电极化（ferroelectric polarization）的影响。为最大化剩余极化强度（2Pr），我们在最优RTA温度条件下通过钨电极引入了面内张应力。实验观测到，随着RTA温度升高，2Pr随之提升，这一现象大概率源于HZO中极性铁电相占比的增加。在400℃下退火的HZO电容器未表现出任何铁电行为；而在800℃下退火的HZO电容器则出现严重漏电，且当施加电压超过1V时发生短路。与之相对，在700℃下退火制备的HZO电容器在111kHz的较高工作频率下，实现了约64 μC·cm⁻²的创纪录高2Pr值。此外，这类铁电电容器还展现出优异的耐久性与保持特性，将极大助力神经形态计算（neuromorphic computing）相关应用的发展。