X-ray spectromicroscopy investigation of soft and hard breakdown in RRAM devices
X-ray spectromicroscopy investigation of soft and hard breakdown in RRAM devices
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DOI：
10.1088/0957-4484/27/34/345705
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发表时间：
2016-08-26
期刊：
影响因子：
3.5
通讯作者：
Prodromakis, T.
中科院分区：
文献类型：
--
作者：
Carta, D.;Guttmann, P.;Prodromakis, T.
电阻式随机存取存储器 (RRAM) 因其具有竞争力的可扩展性、低功耗运行和高开关速度而被认为是下一代存储设备的有吸引力的候选者。然而，该技术仍然面临着一些总体上阻碍其工业转化的挑战，例如低产量、大的开关变化以及由于长期运行或高电压偏置而最终导致的硬击穿。后一个问题特别令人感兴趣，因为它最终会导致设备故障。在这项工作中，我们通过将全场透射 X 射线显微镜与对薄片样品进行的软 X 射线光谱分析相结合，研究了 RRAM 器件中因软击穿和硬击穿而发生的物理化学变化。该技术的高横向分辨率（低至 25 nm）允许研究金属顶部电极永久损伤下方的局部纳米区域。结果表明，硬击穿后的器件在有源层、Pt 夹杂物和金红石等晶相的形成中呈现出不连续性，这表明温度局部升高至 1000 K。
Resistive random access memory (RRAM) is considered an attractive candidate for next generation memory devices due to its competitive scalability, low-power operation and high switching speed. The technology however, still faces several challenges that overall prohibit its industrial translation, such as low yields, large switching variability and ultimately hard breakdown due to long-term operation or high-voltage biasing. The latter issue is of particular interest, because it ultimately leads to device failure. In this work, we have investigated the physicochemical changes that occur within RRAM devices as a consequence of soft and hard breakdown by combining full-field transmission x-ray microscopy with soft x-ray spectroscopic analysis performed on lamella samples. The high lateral resolution of this technique (down to 25 nm) allows the investigation of localized nanometric areas underneath permanent damage of the metal top electrode. Results show that devices after hard breakdown present discontinuity in the active layer, Pt inclusions and the formation of crystalline phases such as rutile, which indicates that the temperature increased locally up to 1000 K.