Local electrical characterization of laser-recorded phase-change marks on amorphous Ge2Sb2Te5 thin films
Local electrical characterization of laser-recorded phase-change marks on amorphous Ge2Sb2Te5 thin films
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DOI：
10.1364/oe.19.009492
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发表时间：
2011-05-09
期刊：
影响因子：
3.8
通讯作者：
Tsai, Din Ping
中科院分区：
文献类型：
--
作者：
Chang, Chia Min;Chu, Cheng Hung;Tsai, Din Ping
研究了溅射沉积在薄膜金电极上的Ge2Sb2Te5非晶薄膜在聚焦激光束影响下记录标记的局部电导率。由于是无定形的，沉积的硫族化物薄膜的导电性可以忽略不计。然而，在聚焦激光束的帮助下，我们在这些薄膜上写下了微米级的晶体标记，被晶体环包围的烧蚀孔，以及包含非晶区和结晶区的其他多环结构。在这些结构中，我们利用高分辨率、高灵敏度的导电尖端原子力显微镜（C-AFM）绘制和探测了具有优异局部导电性的纳米级区域。扫描电子显微镜和能量色散光谱也被用来澄清在记录的标记和周围的高电导率的起源。当Ge2Sb2Te5层足够薄时，当使用激光结晶/烧蚀来定义样品上的长隔离晶体条纹时，我们发现基于c - afm的方法从记录的标记中提取信息优于其他形式的显微镜。鉴于硫属化合物作为高密度存储器的主要介质候选材料的巨大潜力，沉积在非晶Ge2Sb2Te5薄膜上记录的标记的局部电特性为进一步研究和开发这一重要现代技术领域提供了有用的信息。(C) 2011美国光学学会
Amorphous thin films of Ge2Sb2Te5, sputter-deposited on a thin-film gold electrode, are investigated for the purpose of understanding the local electrical conductivity of recorded marks under the influence of focused laser beam. Being amorphous, the as-deposited chalcogenide films have negligible electrical conductivity. With the aid of a focused laser beam, however, we have written on these films micron-sized crystalline marks, ablated holes surrounded by crystalline rings, and other multi-ring structures containing both amorphous and crystalline zones. Within these structures, nano-scale regions of superior local conductivity have been mapped and probed using our high-resolution, high-sensitivity conductive-tip atomic force microscope (C-AFM). Scanning electron microscopy and energy-dispersive spectrometry have also been used to clarify the origins of high conductivity in and around the recorded marks. When the Ge2Sb2Te5 layer is sufficiently thin, and when laser crystallization/ ablation is used to define long isolated crystalline stripes on the samples, we find the C-AFM-based method of extracting information from the recorded marks to be superior to other forms of microscopy for this particular class of materials. Given the tremendous potential of chalcogenides as the leading media candidates for high-density memories, local electrical characterization of marks recorded on as-deposited amorphous Ge2Sb2Te5 films provides useful information for furthering research and development efforts in this important area of modern technology. (C) 2011 Optical Society of America