At 1× node, a three-dimensional (3-D) FinFET process raises a number of new metrology challenges for process control, including gate height and fin height. At present, there is a metrology gap in inline in-die measurement of these parameters. To fill this metrology gap, in-column beam tilt has been implemented on Applied Materials V 4iþ critical dimension scanning electron microscope for height measurement. Low-tilt (5 deg) and high-tilt (14 deg) beam angles have been calibrated to obtain the height and the sidewall angle information. Evaluation of its feasibility and production worthiness is done with applications in both gate height and fin height measurements. Transmission electron microscope correlation with an R 2 equal to 0.89 and a precision of 0.81 nm have been achieved on various in-die features in a gate height application. The initial fin height measurement shows less accuracy (R 2 being 0.77) and precision (1.49 nm) due to greater challenges brought by the fin profile, yet it is promising for the first attempt. Sensitivity to design of experiment offset die-todie and in-die variations is demonstrated in both gate height and fin height. The process defect is successfully captured with inline gate height measurement. This is the first successful demonstration of inline in-die gate height measurement for a 14-nm FinFET process control.

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As design rules shrink, there is an increase in the complexity. OPC/RET have been facilitating unprecedented yield at k 1 factors, they increase the mask complexity and production cost, and can introduce yield-detracting errors. Currently OPC modeling techniques are based on extensive CD-SEM measurements which are limited to one dimensional structures or specific shape structures e.g. contact holes. As a result the measured information is not representing the whole spatial 2D change in the process. Therefore the most common errors are found in the OPC design itself and in the resulting patterning robustness across the process window. A new methodology for OPC model creation and verification is to extract contours from complex test structures which beside the CD values contain further information about e.g. various proximities.In this work we use 2D contour profiles extracted automatically by the CD-SEM over varying focus and exposure conditions. We will show that the measurement sensitivity and uncertainty of that algorithm through the whole process window fulfills the requirements of the ITRS with respect to CD-SEM metrology tools. This will be done on various test structures normally being used for OPC model generation and OPC stability monitoring. Furthermore a study on systematic influences on the quality of the extracted contours has been started. This study includes the evaluation of various parameters which are considered as possible contributors to the uncertainty of the edge contour extraction. As one of the parameters we identified the pixel size of the SEM images. Furthermore, a new metric for calculating repeatability and reproducibility determination for 2D contour extraction algorithms will be presented. By applying this contour extraction based methodology to different CD-SEM tool generations the influence of SEM beam resolution to the quality of the contours will be evaluated.

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