Recently, chalcogenide materials have exhibited ovonic threshold switching characteristics, improving their suitability as selector devices to effectively depress the sneak current in the cross-point array (CPA) structures. However, chalcogenides must be subjected to a firing process before they can exhibit the threshold switching behavior. The firing process causes operation problems with respect to the memory operation process in the case of the CPA structure. Although the firing process is expected to be related to Joule heating with a high electric current, the physical nature of the changes during the firing process remains unclear. In this study, selector devices are fabricated by sandwiching amorphous Ge–As–Te thin films between the TiN and W layers. Furthermore, the authors examine the microstructure of the Ge–As–Te thin films before and after the electric firing process using transmittance electron microscopy (TEM, JEOL JEM-F200). The TEM analysis of the pristine Ge–As–Te thin films denotes the uniform contrast of the image, which implies the uniform chemical composition of the film. However, the Ge–As–Te thin films exhibit nonuniform contrast due to the effects of Joule heating after the electric firing process. The Ge–As–Te thin films were thermally annealed at 150 and 250 °C for 1 min via the rapid thermal annealing process to verify the effects of thermal treatment on the firing process in chalcogenide thin films. The effect of thermal annealing on the threshold switching behavior was also investigated by studying the compositional stability. Their results showed that the thermal annealing process caused the uniform compositions on the pristine Ge–As–Te films to be fluctuated with decreasing firing voltage for threshold switching.

中文翻译：

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具有ovonic阈值切换的热退火Ge-As-Te薄膜的点火电压降低

最近，硫属化物材料已经表现出 ovonic 阈值切换特性，提高了它们作为选择器器件的适用性，以有效地抑制交叉点阵列 (CPA) 结构中的潜行电流。然而，硫属化物必须经过烧制过程才能表现出阈值切换行为。在 CPA 结构的情况下，触发过程会导致与内存操作过程相关的操作问题。尽管预计烧制过程与高电流焦耳加热有关，但烧制过程中变化的物理性质仍不清楚。在这项研究中，选择器器件是通过将非晶 Ge-As-Te 薄膜夹在 TiN 和 W 层之间来制造的。此外，作者使用透射电子显微镜（TEM，JEOL JEM-F200）在电烧制过程之前和之后检查了 Ge-As-Te 薄膜的微观结构。原始 Ge-As-Te 薄膜的 TEM 分析表明图像的均匀对比度，这意味着薄膜的均匀化学成分。然而，由于电烧制过程后焦耳热的影响，Ge-As-Te 薄膜表现出不均匀的对比度。Ge-As-Te 薄膜通过快速热退火工艺在 150 和 250°C 下热退火 1 分钟，以验证热处理对硫属化物薄膜烧制过程的影响。还通过研究成分稳定性研究了热退火对阈值转换行为的影响。