Oh Seung Ik, Im In Hyuk, Yoo Chanyoung, Ryu Sung Yeon, Kim Yong, Choi Seok, Eom Taeyong, Hwang Cheol Seong, Choi Byung Joon
Department of Materials Science and Engineering, Seoul National University of Science and Technology (Seoultech), Seoul 01811, Korea.
Department of Materials Science and Engineering, and Inter-University Semiconductor Research Center, Seoul National University, Seoul 08826, Korea.
Micromachines (Basel). 2019 Apr 27;10(5):281. doi: 10.3390/mi10050281.
The electrical switching behavior of the GeTe phase-changing material grown by atomic layer deposition is characterized for the phase change random access memory (PCRAM) application. Planar-type PCRAM devices are fabricated with a TiN or W bottom electrode (BE). The crystallization behavior is characterized by applying an electrical pulse train and analyzed by applying the Johnson-Mehl-Avrami kinetics model. The device with TiN BE shows a high Avrami coefficient (>4), meaning that continuous and multiple nucleations occur during crystallization (set switching). Meanwhile, the device with W BE shows a smaller Avrami coefficient (~3), representing retarded nucleation during the crystallization. In addition, larger voltage and power are necessary for crystallization in case of the device with W BE. It is believed that the thermal conductivity of the BE material affects the temperature distribution in the device, resulting in different crystallization kinetics and set switching behavior.
对通过原子层沉积生长的GeTe相变材料的电开关行为进行了表征，以用于相变随机存取存储器（PCRAM）应用。采用TiN或W底部电极（BE）制造平面型PCRAM器件。通过施加电脉冲序列来表征结晶行为，并应用Johnson-Mehl-Avrami动力学模型进行分析。具有TiN BE的器件显示出高Avrami系数（>4），这意味着在结晶（设置切换）过程中发生连续和多次成核。同时，具有W BE的器件显示出较小的Avrami系数（~3），这表明在结晶过程中成核受到抑制。此外，对于具有W BE的器件，结晶需要更大的电压和功率。据信，BE材料的热导率会影响器件中的温度分布，从而导致不同的结晶动力学和设置切换行为。
