Highly dynamic 4DOF Piezo Wafer Stage for inspection and metrology
Leveraging decades of piezo nanopositioning technology experience, introducing at 2024 Semicon West.
PI’s newest wafer inspection solution is based on a hybrid kinematics design, combining Piezo-Walk motors and piezo stacks to achieve both long travel and highly dynamic, ultra-precise motion. This integrated 4-DOF solution reduces equipment complexity, integration efforts, costs, and risks.
Piezo-Walk motors are self-locking at rest, adding no servo dither and heat, unlike other motion techniques. The high bandwidth of the short-travel piezo stack actuators allows for dynamic tracking and error compensation of external disturbances (e.g., from long travel XY wafer stages).
The 4DOF module can also correct for rotational wafer misalignment and takes wafer thickness and machine static characteristics into account.
The high-stiffness design of the Tip-Tilt drive module provides extremely fast step and settle (<10msec) and position stability (<0.05µrad).
