Stage Automation Software

Featured at Semicon West

FEI Company announces Moves automation software for the XL800 Series of SEM and DualBeam defect review and characterization tools, which provides operators with automated access to images of a specific submicron defect. The stage software increases the number of defects that can be characterized per hour by automatically compensating for sample rotation and tilt, controlling complex stage motions, and creating wafer height maps. Operators can bring a specific defect into focus quickly and then concentrate on studying and analyzing the images instead of spending time re-adjusting the SEM imaging parameters every time the defect is moved for observation.

Moves works with FEI's high-accuracy 5-axis 200-mm wafer stage to keep the defect in the field of view and automatically adjust parameters affecting image quality during the most complex motions. When similar samples are loaded repeatedly, the system can be pre-programmed to quickly drive to the desired points on the sample, such as alignment points or known areas of interest. High-resolution SEM imaging is extremely sensitive to movement of the feature relative to the electron beam. However, operators must often view defects from several angles to be able to quickly and accurately characterize the defect and move on to the next one. They require stage control software that automatically brings sub-micron defects into the optimum imaging position with the shortest working distance and keeps the image on the screen and in focus after tilt and rotation.

As parameters are changed that affect beam position and intensity, the software automatically compensates. It includes more than a dozen variables in its multidimensional matrix, such as how position and focus change with beam voltage, how working distance changes with rotation, and how brightness changes with spot size. It keeps a feature anywhere on the wafer focused and in its optimal imaging position on the screen during stage rotation, tilt, and X,Y,Z movement of the defect for full observation.

This new stage control software enables the most complex stage motions to be performed, including compucentric rotation, compucentric tilt, and eucentric tilt. It automatically handles the complex, interrelated, and (manually tedious) set of adjustments that were once a standard part of SEM operation in the lab. Moves software creates a wafer height map using auto-eucentric height tracking and uses it to adjust and optimize the working distance and image quality when moving to a new location. The shortest working distance is maintained, regardless of whether the wafer is held flat or tilted. The system automatically compensates for wafer warpage. Running on a user-friendly Windows GUL Moves software helps new operators to become quickly proficient and occasional users to maintain full competency.

FEI Company, Contact: Pat Finney, 503-640-7500.