Since the discovery of ferroelectric properties in doped HfO2, various types of memory devices have emerged based on this novel material. Especially, the ferroelectric tunnel junction (FTJ) has gained considerable attention for selector-less crossbar array. Although various studies have been carried out for the HfO2-based FTJs, there are no investigations of them at a cryogenic temperature. While cryogenic memories are getting increasing attentions for diverse applications from high-performance computing to aerospace electronics, exploring the FTJ at cryogenic temperature is particularly interesting because it has been known for relatively poor retention characteristics and endurance at room temperature (RT). For the first time, we characterize the HfO2-based FTJ at cryogenic temperature down to 77 K. It was found that both the retention and endurance characteristics become greatly improved at 77 K. Furthermore, the read voltage was found to be critical for optimized performance in terms of ON-current, OFF-current, and their ratio at 77 K.

中文翻译：

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在低温下表征基于 HfO2 的铁电隧道结,在低温下表征基于 HfO2 的铁电隧道结

Since the discovery of ferroelectric properties in doped HfO2, various types of memory devices have emerged based on this novel material. Especially, the ferroelectric tunnel junction (FTJ) has gained considerable attention for selector-less crossbar array. Although various studies have been carried out for the HfO2-based FTJs, there are no investigations of them at a cryogenic temperature. While cryogenic memories are getting increasing attentions for diverse applications from high-performance computing to aerospace electronics, exploring the FTJ at cryogenic temperature is particularly interesting because it has been known for relatively poor retention characteristics and endurance at room temperature (RT). For the first time, we characterize the HfO2-based FTJ at cryogenic temperature down to 77 K. It was found that both the retention and endurance characteristics become greatly improved at 77 K. Furthermore, the read voltage was found to be critical for optimized performance in terms of ON-current, OFF-current, and their ratio at 77 K.,自从在掺杂的 HfO2 中发现铁电特性以来，基于这种新型材料的各种类型的存储设备已经出现。特别是，铁电隧道结（FTJ）在无选择器交叉开关阵列中引起了广泛关注。尽管已经对基于 HfO2 的 FTJ 进行了各种研究，但没有在低温下对其进行研究。虽然低温存储器在从高性能计算到航空航天电子的各种应用中越来越受到关注，但在低温下探索 FTJ 特别有趣，因为众所周知它在室温 (RT) 下的保留特性和耐久性相对较差。我们首次在低至 77 K 的低温下表征基于 HfO2 的 FTJ。