In this paper we compare the performances of SiN with respect to an optimized SiC encapsulation in Wall based Phase-Change Memory (PCM) integrating a Ge-rich Ge-Sb-Te alloy (GGST) suitable for high temperature stability in automotive applications. Thanks to the electrical characterization of 4 kb arrays, 3D electro-thermal simulations and TEM analyses performed on programmed devices, we demonstrate the higher programming efficiency in SiC-based PCM devices, thanks to the lower thermal conductivity of the optimized encapsulation. Indeed, the uniform temperature profile achieved in the active layer of SiC encapsulated PCM leads to a retention of one hour at 250 °C. A theoretical model is here proposed to describe the electro-thermal behavior of the device, linking the electrical properties, such as the resistance as a function of current characteristics, to the thermal conductivity of the materials that constitute the device. Finally, thanks to our findings, we provide some guidelines to achieve drastic current reduction via the thermal engineering of the next generation PCM technology.

在本文中，我们比较了 SiN 与壁基相变存储器 (PCM) 中优化 SiC 封装的性能，该存储器集成了适用于汽车应用中高温稳定性的富锗 Ge-Sb-Te 合金 (GGST)。由于 4 kb 阵列的电气特性、3D 电热模拟和对已编程器件进行的 TEM 分析，我们证明了基于 SiC 的 PCM 器件具有更高的编程效率，这要归功于优化封装的较低热导率。事实上，在 SiC 封装的 PCM 有源层中实现的均匀温度分布导致在 250 °C 下保持一小时。这里提出了一个理论模型来描述器件的电热行为，将电气特性联系起来，例如作为电流特性函数的电阻，以及构成器件的材料的热导率。最后，由于我们的发现，我们提供了一些指导方针，通过下一代 PCM 技术的热工程实现大幅电流降低。