共查询到19条相似文献,搜索用时 875 毫秒
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通过磁控溅射仪制备了Ge2Sb2Te5(GST)和Ag10.6(GST)89.4薄膜,利用X射线衍射(XRD)、电阻-温度(RT)测试、透射电子显微学以及径向分布函数(RDF)等方法对比研究了GST和Ag10.6(GST)89.4的结晶过程和微观结构及其演化的差异。发现掺Ag的薄膜非晶态、晶态电阻均比GST更高,而且结晶过程只有非晶相到面心立方相(fcc)的转变,没有出现GST的非晶到fcc再到六方相(hcp)的过程,XRD分析进一步证实了这一结果。同时,透射电镜原位加热实验证实了在300℃时,Ag10.6(GST)89.4仍然保持着fcc结构,而GST中已经出现了hcp相。通过统计230℃下时效处理的晶态薄膜的晶粒尺寸,发现Ag10.6(GST)89.4的平均晶粒尺寸小于Ge2Sb2Te5薄膜的,这可能是造成其晶态电阻高于GST的主要原因。 相似文献
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采用射频磁控溅射方法,分别在玻璃和具有本征氧化层的Si(100)基片上制备了Ge2Sb2Te5相变薄膜。利用X射线衍射仪、扫描电镜(SEM)、原子力显微镜(AFM)、紫外分光光度计等对薄膜进行了表征,研究了不同生长温度(室温~300℃)的Ge2Sb2Te5薄膜的表面形貌和结晶特性。分析结果表明:室温沉积的薄膜为非晶态;沉积温度为100℃~250℃时,薄膜转变为晶粒尺度约14nm的面心立方结构;300℃~350℃沉积的薄膜有少量的六方相出现。薄膜表面粗糙度随着沉积温度的升高逐渐递增,且薄膜的反射率变化与表面粗糙度有直接的关系。 相似文献
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掺GeZnSe的稳恒光电导及其局域性效应 总被引:1,自引:1,他引:0
在一定的温度以下 ,某些半导体材料的光电导效应在激发光源撤去以后会持久地保持下去 ,当温度升高超过这个温度 (称为淬变温度 )以后 ,这种持续的光电导现象会消除 ,称为稳恒光电导现象 .而且这种光电导效应具有很强的局域性 .采用电学测量方法 ,通过测量激光照射前后电导率随温度的变化研究了掺 Ge的 Zn Se的稳恒光电导效应 ,结果发现淬变温度高达 2 1 0 K的稳恒光电导效应 .并通过研究光电阻随光照位置变化的趋势研究了这种光电导的局域性特性 ,结果发现在淬变温度以上局域性随稳恒光电导消失而消失 相似文献
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介绍研究薄膜的新方法--能量过滤电子衍射法,该方法借助透射电镜样品后扫描,薄膜的选区电子衍射花样顺序地扫过电子能量损失谱仪入口光闽,检测弹性散射电子强度与散射矢量关系,然后由径向分布函数理论,导出薄膜材料的最近邻原子间距和配位数等与结构有关的信息。通过多晶金薄膜和非晶钛铝薄膜的测试,获得满意结果。 相似文献
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利用飞秒激光的抽运探测技术,研究了单脉冲飞秒激光作用下GeSb2Te4相变薄膜的非晶化过程,测量了相变薄膜的时间分辨光学显微图。所研究的系统为多层薄膜结构100 nm ZnS-SiO2/ 35 nm GeSb2Te4 /120 nm ZnS-SiO2/0.6 mm ,飞秒激光的脉冲宽度为108 fs,波长为800 nm。实验发现相变薄膜从晶态至非晶态的相转变过程可以在 2.6 ns内完成。讨论了相变薄膜的厚度对系统的热传递、快速凝固过程的影响,分析了相关热过程和热效应,解释了抽运探测实验数据,并探讨了单脉冲飞秒激光诱导相变薄膜非晶化的机制。 相似文献
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Dong-Ho Ahn Dae-Hwan Kang Byung-ki Cheong Hyuk-Soon Kwon Min-Ho Kwon Tae-Yeon Lee Jeung-hyun Jeong Taek Sung Lee In Ho Kim Ki-Bum Kim 《Electron Device Letters, IEEE》2005,26(5):286-288
A nonvolatile memory technology utilizing reversible changes between fcc and hcp crystalline phases is proposed. In this new type of phase-change memory, data are stored in different forms of crystalline phases of (Ge/sub 1/Sb/sub 2/Te/sub 4/)/sub 0.8/(Sn/sub 1/Bi/sub 2/Te/sub 4/)/sub 0.2/ chalcogenide alloy. RESET operation produces the less conductive metastable fcc phase via melt-quenching from the more conductive stable hcp phase and SET operation involves a phase change from fcc directly to hcp. Both RESET and SET operations can be completed as fast as 70 ns with large changes in cell resistance. 相似文献
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Semiconductors - For the first time, the GeSb2Te4–PbSb2Te4 section of the GeTe–Sb2Te3–PbTe quasi-ternary system is investigated by complex methods of physicochemical analysis... 相似文献
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信息时代产生的海量数据驱动着计算机存储架构的革新,高性能的非易失性存储器和存算一体的神经形态计算成为存储体系的发展方向。首先,介绍了相变材料Ge2Sb2Te5的阻变性质的机理与应用,详细阐述了相变存储器的发展以及神经形态计算的实现。然后,讨论了基于Ge2Sb2Te5铁电性质的存储器、基于Ge2Sb2Te5介电性质的光子存储单元和基于Ge2Sb2Te5应变作用的高迁移率晶体管。最后,讨论了Ge2Sb2Te5和n型硅等材料的异质结结构在器件中的应用。基于Ge2Sb2Te5材料多种特性的新型存储器件必将在未来存算一体的数据处理中扮演重要的角色。 相似文献
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Koji Ohara László Temleitner Kunihisa Sugimoto Shinji Kohara Toshiyuki Matsunaga László Pusztai Masayoshi Itou Hiroyuki Ohsumi Rie Kojima Noboru Yamada Takeshi Usuki Akihiko Fujiwara Masaki Takata 《Advanced functional materials》2012,22(11):2251-2257
Ge2Sb2Te5 (GST) has demonstrated its outstanding importance among rapid phase‐change (PC) materials, being applied for optical and electrical data storage for over three decades. The mechanism of nanosecond phase change in GST, which is vital for its application, has long been disputed: various, quite diverse scenarios have been proposed on the basis of various experimental and theoretical approaches. Nevertheless, one central question still remains unanswered: why is amorphous GST stable at room temperature for long time while it can rapidly transform to the crystalline phase at high temperature? Here it is revealed for the first time, by modelling the amorphous structure based on synchrotron radiation anomalous X‐ray scattering data, that germanium and tellurium atoms form a “core” Ge‐Te network with ring formation. It is also suggested that the Ge‐Te network can stabilize the amorphous phase at room temperature and can persist in the crystalline phase. On the other hand, antimony does not contribute to ring formation but constitutes a “pseudo” network with tellurium, in which the characteristic Sb–Te distance is somewhat longer than the covalent Sb–Te bond distance. This suggests that the Sb‐Te pseudo network may act as a precursor to forming critical nuclei during the crystallization process. The findings conclude that the Ge‐Te core network is responsible for the outstanding stability and rapid phase change of the amorphous phase while the Sb‐Te pseudo network is responsible for triggering critical nucleation. 相似文献
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Liu Yanbo Zhang Ting Niu Xiaoming Song Zhitang Min Guoquan Zhang Jing Zhou Weimin Wan Yongzhong Zhang Jianping Li Xiaoli Feng Songlin 《半导体学报》2009,30(6)
The Si2Sb2Te5 phase change material has been studied by applying a nano-tip (30 nm in diameter) on an atomic force microscopy system. Memory switching from a high resistance state to a low resistance state has been achieved, with a resistance change of about 1000 times. In a typical Ⅰ-Ⅴ curve, the current increases significantly after the voltage exceeds~4.3 V. The phase transformation of a Si2Sb2Te5 film was studied in situ by means of in situ X-ray diffraction and temperature dependent resistance measurements. The thermal stability of Si2Sb2Te5 and Ge2Sb2Te5 was characterized and compared as well. 相似文献
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从电化学角度研究了Ge2Sb2Te5薄膜在化学机械抛光液中的作用,以及不同的pH值和H2O2浓度下的电化学特性. 采用Solartron SI1287电化学设备测试了Ge2Sb2Te5薄膜在溶液中的开路电位和动电位扫描. 开路电位结果表明:Ge2Sb2Te5在pH值为10的抛光液中表现出钝化行为;而抛光液的pH值为11时,开始向活化转变;当pH值为12时,薄膜处于活化状态. 在动电位扫描过程中,不同的pH值和H2O2浓度下,薄膜的扫描曲线形状相似,表明薄膜腐蚀具有相同的反应机理. 自制碱性抛光液,对Ge2Sb2Te5薄膜进行化学机械抛光,用SEM和EDS对抛光后的结构进行分析. 结果表明,通过CMP实现了Ge2Sb2Te5填充结构. 相似文献
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利用椭偏光谱术与XRD对钛掺杂Ge2Sb2Te5薄膜中钛元素对体系的光学性质及其微结构的影响进行了实验研究。进而对该薄膜进行的变温阻抗实验表明,钛掺杂Ge2Sb2Te5薄膜与未掺杂的薄膜相比具有更好的热稳定性。基于对薄膜样品的数据保持能力测试的实验数据,经阿伦纽斯外推处理可知,钛掺杂Ge2Sb2Te5薄膜样品的10年数据保持温度要高于未掺杂Ge2Sb2Te5薄膜样品。本文的实验结果均证实,钛掺杂Ge2Sb2Te5薄膜更适合应用于相变随机存取存储器中。 相似文献