Measurement and correction of sample holder and stage tilt in metrology systems

Abstract

Methods and systems are provided for aligning a sample holder in a metrology system. The metrology system includes a process module mounted on a vacuum chamber interface and defining a process axis, a sample stage assembly with translational and rotational stages, and a sample holder configured to hold a sample. The method includes determining an actual spatial arrangement of the sample holder surface, calculating required spatial corrections, and adjusting the sample holder surface to achieve a desired spatial arrangement using spacing elements disposed between adjacent components in the mechanical stack of system components. The spacing elements may be separate removable elements or integrally formed features of one or more components in the mechanical stack of system components. Multiple measurements at different rotational and translational positions enable separation of sample holder tilt and rotation stage tilt components. Additionally, or alternatively, active control parameters for at least one linear sample stage may be determined to maintain working distance during operation. The system achieves repeatable and stable sample holder alignment without tight manufacturing tolerances or movable adjustment mechanisms.

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