Center for Applied Near-Field Optics Research, National Institute of Applied Industrial Science and Technology, Tsukuba Central4, 1-1-1 Higashi, Tsukuba 305-8562, Japan.
Nano Lett. 2010 Feb 10;10(2):414-9. doi: 10.1021/nl902777z.
The limit to which the phase change memory material Ge(2)Sb(2)Te(5) can be scaled toward the smallest possible memory cell is investigated using structural and optical methodologies. The encapsulation material surrounding the Ge(2)Sb(2)Te(5) has an increasingly dominant effect on the material's ability to change phase, and a profound increase in the crystallization temperature is observed when the Ge(2)Sb(2)Te(5) layer is less than 6 nm thick. We have found that the increased crystallization temperature originates from compressive stress exerted from the encapsulation material. By minimizing the stress, we have maintained the bulk crystallization temperature in Ge(2)Sb(2)Te(5) films just 2 nm thick.
使用结构和光学方法研究了相变存储材料 Ge(2)Sb(2)Te(5) 能够缩小到最小可能存储单元的极限。封装材料对 Ge(2)Sb(2)Te(5) 材料相变能力的影响越来越大，当 Ge(2)Sb(2)Te(5)层厚度小于 6nm 时，观察到结晶温度显著升高。我们发现，升高的结晶温度源于封装材料产生的压应力。通过最小化应力，我们将厚度仅为 2nm 的 Ge(2)Sb(2)Te(5)薄膜的体结晶温度保持在正常水平。
