The Nanoscale Electrical Damage Mechanism of Ge2Sb2Te5 Phase-Change Films Discovered by Conductive Atomic Force Microscopy

作者：Xu, Xionghu; Li, Ming; Li, Shubing; Cui, Anyang; Deng, Menghan; Jiang, Kai; Zhu, Liangqing^*; Shang, Liyan; Chu, Junhao; Hu, Zhigao^*

来源：IEEE Electron Device Letters, 2023, 44(3): 488-491.

DOI：10.1109/LED.2023.3237230

• C-AFM
• GST films
• phase-change
• Joule heat
• crystallinity

We study the nanoscale electrical damage of Ge2Sb2Te5 (GST) phase-change films during crystallization by conductive atomic force microscopy (C-AFM) and Raman spectra. Amorphous GST (a-GST) can be converted to crystalline GST (c-GST) by applying an exciting direct current (DC) bias (8 V) between the tip and the GST surface. Furthermore, as film thickness increased, the electrical-induced region of GST films revealed a gradual increase in electrical damage and improved crystallinity. It shows that GST films with a thickness of 70 nm have a better crystallization ratio of 20.5 % and less electrical damage with a volume expansion rate of 19.1 +/- 6.5%.