Abstract：
HfO2-based ferroelectric materials as the most promising candidate for the ferroelectric memories, have been widely studied for more than a decade due to their excellent ferroelectric properties and CMOS compatibility. In order to realize its industrialization as soon as possible, researchers have been devoted to improving the reliability performance, such as wake up, imprint, limited endurance, et al. Among them, the breakdown characteristic is one of main failure mechanisms of HfO2-based ferroelectric devices, which limits the write/read reliability of the devices. Based on this, we systematically studied the effect of thickness on the time-dependent dielectric breakdown (TDDB) tolerate capability of HfO2-ZrO2(HZO) FE films under both forward and reverse electrical stress conditions. The thickness of HZO FE film ranged from 6 to 20 nm. Our findings reveal that decreasing the thickness of the HZO FE film leads to an improvement in TDDB tolerance capability which is attributed to the fact that higher density of oxygen vacancies in thinner HZO FE films can effectively inhibit the generation of new oxygen vacancies and the growth of conductive filaments, thus effectively improving the TDDB characteristics. These results provide a potential solution for mitigating breakdown characteristics of HfO2-based ferroelectric devices in memory applications.
摘要：
HfO2基铁电材料是最有希望的铁电存储器候选材料,由于其优异的铁电性能和CMOS兼容性,已被广泛研究了十多年。为了尽快实现其产业化,研究人员一直致力于提高可靠性性能，比如醒来，印记,有限的耐力,etal.其中,击穿特性是HfO2基铁电体器件的主要失效机理之一,这限制了设备的写/读可靠性。基于此,在正向和反向电应力条件下，我们系统地研究了厚度对HfO2-ZrO2（HZO）FE薄膜的时间依赖性介电击穿（TDDB）耐受能力的影响。HZOFE薄膜的厚度范围为6nm至20nm。我们的发现表明，降低HZOFE薄膜的厚度会导致TDDB耐受能力的提高，这归因于较薄的HZOFE薄膜中较高的氧空位密度可以有效抑制新的氧空位的产生和导电丝的生长。从而有效地改善了TDDB的特性。这些结果为减轻存储器应用中基于HfO2的铁电装置的击穿特性提供了潜在的解决方案。
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