在通过X射线计算机断层扫描（CT）和与扫描电子显微镜相关光学显微镜（LM）的一个组合的LED深度分析（SEM）的
Summary
一种有源光器件的全面的微特征的工作流程概述。它包含CT，LM和扫描电镜结构以及功能调查。该方法被证明为白色LED可仍然表征期间进行操作。
Abstract
In failure analysis, device characterization and reverse engineering of light emitting diodes (LEDs), and similar electronic components of micro-characterization, plays an important role. Commonly, different techniques like X-ray computed tomography (CT), light microscopy (LM) and scanning electron microscopy (SEM) are used separately. Similarly, the results have to be treated for each technique independently. Here a comprehensive study is shown which demonstrates the potentials leveraged by linking CT, LM and SEM. In depth characterization is performed on a white emitting LED, which can be operated throughout all characterization steps. Major advantages are: planned preparation of defined cross sections, correlation of optical properties to structural and compositional information, as well as reliable identification of different functional regions. This results from the breadth of information available from identical regions of interest (ROIs): polarization contrast, bright and dark-field LM images, as well as optical images of the LED cross section in operation. This is supplemented by SEM imaging techniques and micro-analysis using energy dispersive X-ray spectroscopy.
Introduction
本文演示X射线计算机断层扫描（CT）与相关的光，并在发光二极管（LED）的深度表征示例性电子显微镜（CLEM）的组合的潜力和优势。使用这种技术，可以计划以这样的方式，当一个横截面可以用显微镜成像的电功能是在检体的其余部分保留了微制备的LED。该过程有几个独特的功能：一是规划编制微通过CT获得整个样本的渲染量的援助;其次，通过光学显微镜（LM）具有完整各种可用的成像技术（亮和暗场，偏振对比度等 ）的LED的观察;第三，在LM操作中LED的观察;第四，同一区域的充分各种各样的电子显微成像技术观察，包括备用电子lectron（SE）和背散射电子（BSE）的成像，以及能量色散X射线荧光光谱法（EDX）。
对于照明应用的LED被设计为发射白光，虽然在某些应用中的颜色变化可能是有利的。这个宽的发射不能由发射从一个化合物半导体来实现，由于LED在窄光谱带（ 大约 30纳米半峰全宽（FWHM））发射辐射。因此白色LED灯通常是由组合的蓝色LED与该短波长辐射转化成宽发射过大的光谱范围为1荧光体产生的。颜色可变的LED解决方案通常使用至少三种原色，这通常导致更高的市场价格。2
使用哪种CT，LM或者SEM的，当然是完善的（ 例如 ，在故障分析LED的3 – 15），然而，这里描述的所有三种技术全面和有针对性的组合可以提供新的见解，将使朝着有意义的表征结果更快的轨道。
从在CT感兴趣的区域（投资回报）可以识别和选择的封装器件的三维微观结构分析。与此非破坏性方法，电连接也可以识别并考虑用于进一步制备。二维横截面的确切制剂允许在操作所述装置的调查，尽管该方法的破坏性。横截面，现在可以通过CLEM 16,17使相同ROI的一个非常有效的，灵活的表征与LM以及扫描电镜来表征。通过这种方法，既显微技术的优点可以被组合。例如，感兴趣区在LM的快速识别后跟在SEM高分辨率成像。但此外，信息从相关将LM（ 例如 ，颜色，光学性质，粒度分布）利用SEM的可视化和分析技术（ 例如 ，颗粒大小，表面形貌，元素分布）允许的功能行为和显微白色LED内的更深的理解。
Protocol
Representative Results
Discussion
这种多峰方法的优点包括在所获取的数据的位置相关的相关性。这里所描述的多模式应与每个单独的技术后续分析进行对比。例如，在LM可见发光特性可以为使用SEM / EDS检测挂成分。经CT获得的卷信息可以在以靶向方式制备横截面的深度分析进行扩展。 CT数据还使得能够在随后显微镜调查兴趣可能领域快速定位。此处所描述的方法是最后的几个技术，这使光学性质的微结构，甚至到亚微米结构细节…
Divulgazioni
The authors have nothing to disclose.
Acknowledgements
作者好心承认从“Akademische GESELLSCHAFT利普施塔特”，以及从“Ministerium献给创新，Wissenschaft与研究部des Landes酒店北威州的”金融支持。照片在图1，图2和5礼貌马库斯HORSTMANN，应用科学哈姆 – 利普施塔特大学。
Materials
| X-Ray Computer Tomograph | General Electric | not applicable | type: nanotom s research edition |
| acquisition software | General Electric | not applicable | phoenix Datos| x2 acquisition and corresponding manual |
| reconstruction software | General Electric | not applicable | phoenix Datos| x2 acquisition and corresponding manual |
| rendering software | Volume Graphics | not applicable | VGStudio Max 2.2 and corresponding manual |
| grinder (manual) | Struers | 5296327 | Labopol 21 |
| sample holder | Struers | 4886102 | UniForce |
| grinder (automated) | Struers | 6026127 | Tegramin 25 |
| epoxy resin/hardener | Struers | 40200030/40200031 | Epoxy fix resin / Epoxy fix hardener |
| Ethanol | Struers | 950301 | Kleenol |
| Light Microscope | Zeiss | not applicable | Axio Imager M2m |
| Electron Microscope | Zeiss | not applicable | Sigma |
| CLEM software | Zeiss | not applicable | Axio Vision SE64 Rel.4.9 and corresponding manual |
| CLEM sample holder | Zeiss | 432335-9101-000 | Specimen holder CorrMic MAT Universal B |
| SEM Adapter for CLEM sample holder | Zeiss | 432335-9151-000 | SEM Adapter for Specimen holder CorrMic MAT Universal B |
| sputter coater | Quorum | not applicable | Q150TES |
| EDS detector | Röntec | not applicable | X-Flash 1106 |
| solder | Stannol | 535251 | type: HS10 |
| LED | Lumileds | not applicable | LUXEON Rebel warm white, research sample |
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