在半导体设备的制造过程中，任何污染物的存在都可能导致完成的模具故障。制造方法的最新创新，例如增加SMIF和清洁室技术的使用，将污染物颗粒的数量减少到最少。yabo214无论这些预防措施如何持续观察，应在每个阶段定期监控该过程，直到建立线路为止。建立线路后，需要进行常规监视，以确保控制颗粒。产量的意外降低需要在此过程中的关键阶段进行检查，以找到问题的原因。
使用显微镜和X射线分析的晶片检查
在制造过程中，使用显微镜在所有阶段都检查了晶圆。对较小的半导体装置结构的需求不断增长，导致通过SEM检查逐渐替换了光学显微镜检查。原因之一是因为几个“杀手缺陷”处于或以下是光学显微镜的分辨率限制。当前正在使用的多层设备本质上是高度地形的，而聚合物材料的使用增加导致景深有限，并且与光学显微镜相关的对比度减少，使缺陷识别和表征非常困难。亚博网站下载
The use of与X射线分析集成的SEM在半导体设备上测试颗粒物是一种事实证明的方法。与光学检查相比，这种组合提供了一种识别关键特征的增强技术，以及进行原位分析的可能性。尽管X射线分析适合表征金属颗粒，但由于该方法仅限于元素分析，因此无法清楚地识别无机化合物。yabo214使用有机颗粒会有额外的局限性yabo214，因为X射线检测器对低于原子数11-钠的光元素非常不敏感，因此通常只检测到碳。
Raman Spectroscopy
Raman analysis is a vibrational spectroscopy, and can probe the chemistry of the test sample. A Raman spectrum comprises bands matching the internal vibrational frequencies of molecules. These bands are unique for each material.
拉曼光谱包含带有有关正在测试样品的化学键的综合数据，简单的库搜索可以将这些频段链接起来以检测所研究的材料。
与X射线分析类似，该方法的空间分辨率在微米阶中，尽管已经创建了扫描探针方法以允许亚微米测试。拉曼光谱法不仅提供了样品的化学分析，而且还探讨了样品的结构特性。拉曼带的形状和宽度受晶体质量的影响，而它们的位置对晶格应变敏感。
The Structural and Chemical Analyzer
Renishaw were inspired to create its structural and chemical analyzer (SCA) for SEMs due to the increasing trend of using SEM for wafer inspection. The company combined SEM’s imaging capabilities with the chemical identification and structural data available from Raman spectroscopy, resulting in two powerful material characterization techniques, made possible in a single instrument.
The structural and chemical analyzer is completely configurable, supporting various laser excitation wavelengths for拉曼和光致发光（PL）光谱镜，以及诸如阴极发光（CL）之类的额外技术。它还提供了许多光谱仪模型的连接性。从常规检查系统到多方法研究级分析工作站，该灵活性允许对系统进行量身定制以满足确定的分析要求。
As Raman spectroscopy uses optical wavelengths, it is effective regardless of the SEM operating environment, making the method appropriate for SEMs operating at low vacuum to ultra-high vacuum.
图1说明了拟合到LEO-1450VP SEM的结构和化学分析仪的UHV变体。对于拉曼光谱法，电子束在光谱形成中没有作用，可以利用低加速电压来对样品进行成像，从而避免充电和损坏。在观察颗粒时，这很重要，因为它们很容易被高能电子束损坏，或者与底yabo214物相关并从中被驱逐并从中驱除，从而将其浪费给分析师。在实现了无机物质和有机物种的测试后，可以增加梁电压以使用X射线分析来表征其余颗粒。yabo214
.jpg)
Figure 1.UHV-version of the structural and chemical analyser interface coupled to the LEO-1450VP that was used for this study
TTL设备上的颗粒物
The benefits of theSEM-SCA可以用以下示例来解释；有意污染了一批晶体管晶体管逻辑（TTL）集成电路（IC）晶圆的样品，以模拟导致差的缺陷，通常在钝化之前针对设备故障分析。
The research aims to reveal how to discover the cause of the failures, and to see if these failures are associated to defects or contaminants, to characterize and establish their origin.
图2a显示了SEM图像中的许多微米大小的粒子，使用SCA分析了这些颗粒。yabo214硅底物是强烈的拉曼散射器，因此从颗粒的光谱中减去硅光谱，以突出散发出颗粒的拉曼带。yabo214一个粒子产生的频谱如图2b（红色）所示，该光谱被确定为PMMA谱。
The "green" spectrum is a trait of poly-tetra-fluoroethylene (PTFE), a very frequently used polymer - the particle’s morphology from SEM reveal that it could be a “shaving” from a worn bearing.
Previous examination of this sample using optical microscopy did not reveal the presence of the PMMA particle, as it is optically transparent. It could also not resolve the sub-micrometer morphological detail in the PTFE particle.
The "blue" spectrum reveals that the particle is an assortment of amorphous carbon, silicon carbide, and diamond. A small silicon band linked to the wafer is also present. It is possible that this particle is residue from a lapping process, and its presence indicates that the post-process cleaning regime may require re-evaluation.
在此样品检查中，传统的SEM-EDS组合未能表征图2C中所示的任何颗粒。yabo214O和Al信号从金属的轨道和钝化层开始。这两个无机颗粒在光谱中主要揭示了硅的硅yabo214，从具有小碳峰的基材，而SIC/Diamond/c粒子仅显示碳和硅峰。
.jpg)
Figure 2.a）TTL设备和颗粒的二级电子图像，b）使用Renishaw的SCA获取的原位拉曼光谱，以及cyabo214）典型的EDS颗粒光谱
Conclusions
The SCA-SEM-EDS combination offers a technique to characterize highly metallic, organic, inorganic particles on dies and wafers. It provides an exceptional solution to the needs ofprocess monitoring和device failure analysis
Acknowledgements
Renishaw PLC要感谢海军研究实验室（华盛顿特区）的化学部门使用其设备。app亚博体育
Renishaw is continually improving its products and reserves the right to change specifications without notice.
This information has been sourced, reviewed and adapted from materials provided by Renishaw.
For more information on this source, please visitRenishaw.