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Improving device performance and yield is one of the primary goals of microelectronic research and development. In order to attain this goal, process engineers are focusing on the integration of new materials and the development of new device architectures. For production process control, the two main techniques to monitor device dimensions are CD-SEM and Scatterometry. Despite the excellent repeatability of these techniques, SEM and Scatterometry often suffer from unacceptably large measurement uncertainty, particularly when applied to newly developed device technologies. A consequence of these metrology limitations is a delay in the transition of new process technologies into production. Furthermore, these techniques have not been proven to be effective in measuring 3-dimensional characteristics such as Line Edge Roughness and Line Width Roughness in the Bottom-CD region.A potential alternative to SEM and Scatterometry in many applications is CD-AFM, a highly versatile metrology technique, which is capable of providing consistent, precise 3-dimensional measurements for a wide range of sample types and geometries.In this paper we present a recent CD-AFM scan algorithm enhancement that significantly improves Bottom-CD measurement bias and precision. In addition, we present a separate but complementary enhancement in the CD-AFM scan algorithm, which we have demonstrated to improve overall CD measurement resolution and precision, while increasing scan speed when using advanced CD-AFM Tips. Our results show that the use of these two techniques enhances Line-Edge Roughness and Line-Width Roughness resolution, precision and accuracy.

With the continuous shrinkage of dimensions in the semiconductor industry, the measurement uncertainty is becoming one of the major component that have to be controlled in order to guarantee sufficient production yield for the next technological nodes production. Thus, CD-SEM and Scatterometry techniques have to face new challenges in term of accuracy and subsequently new challenges in measurement uncertainty that were not really taken into account at the origin of their introduction in production. In this paper, we will present and discuss results about the accuracy requirements related to key applications for advanced technological nodes production. Thus, we will present results related to OPC model precision improvement by using suitable reference metrology model based on the 3D-AFM technique use. An interesting study related to 193 resist shrinkage during CD-SEM measurement will be also presented and therefore the impact on measurement uncertainty will be discussed. Finally we will conclude this paper by showing the potential industrial benefits to use a simple but relevant 3D-AFM reference metrology model use into the semiconductor production environment.

The measurement uncertainty is becoming one of the major components that have to be controlled in order to guarantee sufficient production yield. Already at the R&D level, we have to cope up with the accurate measurements of sub-40nm dense trenches and contact holes coming from 193 immersion lithography or EBeam lithography. Current production CD metrology techniques such as CD-SEM and OCD are limited in relative accuracy for various reasons (i.e electron proximity effect, outputs parameters correlation, stack influence, electron interaction with materials…). Therefore, time for R&D is increasing, process windows degrade and finally production yield can decrease because you can not manufactured correctly if you are unable to measure correctly. A new high volume manufacturing (HVM) CD metrology solution has to be found in order to improve the relative accuracy of production environment otherwise current CD Metrology solution will very soon get out of steam. In this paper, we will present a potential Hybrid CD metrology solution that smartly tuned 3D-AFM and CD-SEM data in order to add accuracy both in R&D and production. The final goal for "chip makers" is to improve yield and save R&D and production costs through real-time feedback loop implement on CD metrology routines. Such solution can be implemented and extended to any kind of CD metrology solution. In a 2 nd part we will discuss and present results regarding a new AFM3D probes breakthrough with the introduction of full carbon tips made will E-Beam Deposition process. The goal is to overcome the current limitations of conventional flared silicon tips which are definitely not suitable for sub-32nm nodes production.

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