Bhaskaran Harish, Sebastian Abu, Pauza Andrew, Pozidis Haralampos, Despont Michel
IBM Zurich Research Laboratory, 8803 Rüschlikon, Switzerland.
Rev Sci Instrum. 2009 Aug;80(8):083701. doi: 10.1063/1.3204449.
Encapsulated conducting probes that can sustain high currents are used to study the nanoscale properties of thin-film stacks comprising of a phase-change chalcogenide, Ge(2)Sb(2)Te(5). Scaling studies on this promising candidate for random-access memory devices had thus far required extensive lithography and nanoscale growth. This seriously hampers rapid materials characterization. This article describes the use of two key techniques, an encapsulated conductive probe and its use in retraction mode, whereby the attractive force between tip and sample is used to maintain electrical contact. The effective transformation of nanoscale dots of amorphous Ge(2)Sb(2)Te(5) into the crystalline state is achieved and the electrical conductivity of the transformed structures is probed. The use of retraction force microscopy in a robust manner is demonstrated by reading the conductivity of the crystalline dots. Both these techniques could enable rapid electrical characterization of nanoscale materials, without extensive nanopatterning, thus reducing material development cycles.
能够承受高电流的封装导电探针被用于研究由相变硫族化物Ge(2)Sb(2)Te(5)组成的薄膜堆栈的纳米级特性。迄今为止，对这种有前途的随机存取存储设备候选材料的缩放研究需要广泛的光刻和纳米级生长。这严重阻碍了快速的材料表征。本文描述了两种关键技术的使用，一种是封装导电探针及其在回缩模式下的应用，即利用尖端和样品之间的吸引力来保持电接触。实现了非晶态Ge(2)Sb(2)Te(5)纳米级点向晶态的有效转变，并对转变后结构的电导率进行了探测。通过读取晶态点的电导率，展示了以稳健方式使用回缩力显微镜。这两种技术都能够在无需广泛纳米图案化的情况下对纳米级材料进行快速电学表征，从而缩短材料开发周期。
