用1064nm激光实验研究了HfO2/SiO2薄膜的激光损伤增强效应,实验以薄膜激光损伤阈值70%的激光能量开始,采用N ON 1方式处理薄膜,激光脉冲的能量增量为5J/cm2。实验结果表明,激光处理薄膜表面能使激光损伤阈值平均提高到3倍左右,并且薄... 用1064nm激光实验研究了HfO2/SiO2薄膜的激光损伤增强效应,实验以薄膜激光损伤阈值70%的激光能量开始,采用N ON 1方式处理薄膜,激光脉冲的能量增量为5J/cm2。实验结果表明,激光处理薄膜表面能使激光损伤阈值平均提高到3倍左右,并且薄膜的损伤尺度也明显减小。对有缺陷的薄膜,其缺陷经低能量激光后熔和消除,其抗激光损伤能力得到增强,但增强得并不显著,而薄膜本身的激光预处理,可以使其激光损伤阈值大大提高。展开更多
This study investigated the resistive switching characteristics of the Ni/HfCVPt structure for nonvolatile memory application.The Ni/HfO_2/Pt device showed bipolar resistive switching（RS） without a forming process, ...This study investigated the resistive switching characteristics of the Ni/HfCVPt structure for nonvolatile memory application.The Ni/HfO_2/Pt device showed bipolar resistive switching（RS） without a forming process, and the formation and rupture of conducting filaments are responsible for the resistive switching phenomenon.In addition,the device showed some excellent memory performances,including a large on/off ratio（〉 3×10~5）,very good data retention（〉 10~3 s @ 200℃） and uniformity of switching parameters.Considering these results,the Ni/HfO_2/Pt device has the potential for nonvolatile memory applications.展开更多
Doped HfO_(2)as an emerging ferroelectric material,holds considerable promise for non-volatile memory applications.Epitaxial growth of doped HfO_(2)thin films is widely adopted as an effective technique for revealing ...Doped HfO_(2)as an emerging ferroelectric material,holds considerable promise for non-volatile memory applications.Epitaxial growth of doped HfO_(2)thin films is widely adopted as an effective technique for revealing the intrinsic ferroelectric properties.In this study,based on systematic structural,chemical and electrical investigations,the influences of Mn doping and substrate orientation on ferroelectric properties of Mn-doped HfO_(2)epitaxial thin films are investigated.The results demonstrate that Mn-doped HfO_(2)thin films with orthorhombic phase can be epitaxially grown along[111]out-of-plane direction on both SrTiO_(3)(001)and(110)substrates,and 10%Mn-doping significantly stabilizes the orthorhombic polar phase and enhances the ferroelectric polarization.Interestingly,compared to the films on SrTiO_(3)(001)substrate,the better crystallinity and reduction of oxygen vacancy amount in Mn-doped HfO_(2)films grown on the SrTiO_(3)(110)substrate are observed,which enhance the remanent polarization and reduce the coercive field.It provides an effective approach for the controllable regulation of defects and the enhancement of intrinsic ferroelectricity in HfO_(2)-based materials.展开更多
Compared to traditional perovskite ferroelectric materials,HfO_(2) has emerged as a prominent research focus due to its ability to retain significant ferroelectricity at the nanoscale.However,systematic studies on its...Compared to traditional perovskite ferroelectric materials,HfO_(2) has emerged as a prominent research focus due to its ability to retain significant ferroelectricity at the nanoscale.However,systematic studies on its performance in thicker films remain limited,leaving the intrinsic relationship between thickness variation and ferroelectric properties poorly understood.In this work,we successfully fabricated doped HfO_(2)-based ferroelectric thin films with thicknesses spanning tens to hundreds of nanometers.All these films exhibit robust ferroelectric characteristics,and their ferroelectric properties demonstrate a non-monotonic evolution with increasing thickness.Macroscopic electrical measurements and mesoscale domain switching analysis confirmed that the ferroelectric properties of Ce:HfO_(2) films first diminish and then recover with the increase of film thickness.By further characterizing the evolution of microscopic structures,we elucidate the thickness effects on the grain size distribution and domain structure evolution.This framework clarifies the physical mechanism underlying the thickness-dependent ferroelectric behavior.Our findings provide critical experimental evidence for developing large-scale HfO_(2)-based ferroelectric devices and lay a theoretical foundation for optimizing thick-film ferroelectric materials for practical applications.展开更多
Neuromorphic computing devices leveraging HfO_(2) and ZrO_(2) materials have recently garnered significant attention due to their potential for brain-inspired computing systems.In this study,we present a novel trilaye...Neuromorphic computing devices leveraging HfO_(2) and ZrO_(2) materials have recently garnered significant attention due to their potential for brain-inspired computing systems.In this study,we present a novel trilayer Pt/HfO_(2)/ZrO_(2-x)/HfO_(2)/TiN memristor,engineered with a ZrO_(2-x) oxygen vacancy reservoir(OVR)layer fabricated via radio frequency(RF)sputtering under controlled oxygen ambient.The incorporation of the ZrO_(2-x) OVR layer enables enhanced resistive switching characteristics,including a high ON/OFF ratio(∼8000),excellent uniformity,robust data retention(>105 s),and multilevel storage capabilities.Furthermore,the memristor demonstrates superior synaptic plasticity with linear long-term potentiation(LTP)and depression(LTD),achieving low non-linearity values of 1.36(LTP)and 0.66(LTD),and a recognition accuracy of 95.3%in an MNIST dataset simulation.The unique properties of the ZrO_(2-x) layer,particularly its ability to act as a dynamic oxygen vacancy reservoir,significantly enhance synaptic performance by stabilizing oxygen vacancy migration.These findings establish the OVR-trilayer memristor as a promising candidate for future neuromorphic computing and high-performance memory applications.展开更多
文摘 用1064nm激光实验研究了HfO2/SiO2薄膜的激光损伤增强效应,实验以薄膜激光损伤阈值70%的激光能量开始,采用N ON 1方式处理薄膜,激光脉冲的能量增量为5J/cm2。实验结果表明,激光处理薄膜表面能使激光损伤阈值平均提高到3倍左右,并且薄膜的损伤尺度也明显减小。对有缺陷的薄膜,其缺陷经低能量激光后熔和消除,其抗激光损伤能力得到增强,但增强得并不显著,而薄膜本身的激光预处理,可以使其激光损伤阈值大大提高。
文摘This study investigated the resistive switching characteristics of the Ni/HfCVPt structure for nonvolatile memory application.The Ni/HfO_2/Pt device showed bipolar resistive switching（RS） without a forming process, and the formation and rupture of conducting filaments are responsible for the resistive switching phenomenon.In addition,the device showed some excellent memory performances,including a large on/off ratio（〉 3×10~5）,very good data retention（〉 10~3 s @ 200℃） and uniformity of switching parameters.Considering these results,the Ni/HfO_2/Pt device has the potential for nonvolatile memory applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.52125204,52250281,52422209,92163210,and U21A2066)the Na-tional Key Research and Development Program of China(Grant Nos.2024YFA1208601,2022YFB3807602,and 2022YFB3807604).
文摘Doped HfO_(2)as an emerging ferroelectric material,holds considerable promise for non-volatile memory applications.Epitaxial growth of doped HfO_(2)thin films is widely adopted as an effective technique for revealing the intrinsic ferroelectric properties.In this study,based on systematic structural,chemical and electrical investigations,the influences of Mn doping and substrate orientation on ferroelectric properties of Mn-doped HfO_(2)epitaxial thin films are investigated.The results demonstrate that Mn-doped HfO_(2)thin films with orthorhombic phase can be epitaxially grown along[111]out-of-plane direction on both SrTiO_(3)(001)and(110)substrates,and 10%Mn-doping significantly stabilizes the orthorhombic polar phase and enhances the ferroelectric polarization.Interestingly,compared to the films on SrTiO_(3)(001)substrate,the better crystallinity and reduction of oxygen vacancy amount in Mn-doped HfO_(2)films grown on the SrTiO_(3)(110)substrate are observed,which enhance the remanent polarization and reduce the coercive field.It provides an effective approach for the controllable regulation of defects and the enhancement of intrinsic ferroelectricity in HfO_(2)-based materials.
基金supported by the National Natural Science Foundation of China(Nos.12372331,12072307,and 12302429)the Science and Technology Innovation Program of Hunan Province,China(No.2024RC3160)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110116).
文摘Compared to traditional perovskite ferroelectric materials,HfO_(2) has emerged as a prominent research focus due to its ability to retain significant ferroelectricity at the nanoscale.However,systematic studies on its performance in thicker films remain limited,leaving the intrinsic relationship between thickness variation and ferroelectric properties poorly understood.In this work,we successfully fabricated doped HfO_(2)-based ferroelectric thin films with thicknesses spanning tens to hundreds of nanometers.All these films exhibit robust ferroelectric characteristics,and their ferroelectric properties demonstrate a non-monotonic evolution with increasing thickness.Macroscopic electrical measurements and mesoscale domain switching analysis confirmed that the ferroelectric properties of Ce:HfO_(2) films first diminish and then recover with the increase of film thickness.By further characterizing the evolution of microscopic structures,we elucidate the thickness effects on the grain size distribution and domain structure evolution.This framework clarifies the physical mechanism underlying the thickness-dependent ferroelectric behavior.Our findings provide critical experimental evidence for developing large-scale HfO_(2)-based ferroelectric devices and lay a theoretical foundation for optimizing thick-film ferroelectric materials for practical applications.
基金financially supported by the National Research Foundation of Korea(no.NRF-2021R1A2C2010781)grant funded by the Korean Government(Ministry of Science and ICT)Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(no.P0012451,The Competency Development Program for Industry Specialist)Korea Government(MOTIE)(no.P0020966,HRD Program for Industrial Innovation).
文摘Neuromorphic computing devices leveraging HfO_(2) and ZrO_(2) materials have recently garnered significant attention due to their potential for brain-inspired computing systems.In this study,we present a novel trilayer Pt/HfO_(2)/ZrO_(2-x)/HfO_(2)/TiN memristor,engineered with a ZrO_(2-x) oxygen vacancy reservoir(OVR)layer fabricated via radio frequency(RF)sputtering under controlled oxygen ambient.The incorporation of the ZrO_(2-x) OVR layer enables enhanced resistive switching characteristics,including a high ON/OFF ratio(∼8000),excellent uniformity,robust data retention(>105 s),and multilevel storage capabilities.Furthermore,the memristor demonstrates superior synaptic plasticity with linear long-term potentiation(LTP)and depression(LTD),achieving low non-linearity values of 1.36(LTP)and 0.66(LTD),and a recognition accuracy of 95.3%in an MNIST dataset simulation.The unique properties of the ZrO_(2-x) layer,particularly its ability to act as a dynamic oxygen vacancy reservoir,significantly enhance synaptic performance by stabilizing oxygen vacancy migration.These findings establish the OVR-trilayer memristor as a promising candidate for future neuromorphic computing and high-performance memory applications.
