PI (Physik Instrumente) L.P., a leading provider of precision motion control and nanopositioning solutions, today announced the A-323, a planar air bearing scanner for semiconductor inspection, metrology and photonics applications that demand high throughput. Designed and manufactured in the USA, the A-323 builds on the company’s A-322 planar scanner with a new architecture that improves precision and repeatability, enables higher acceleration and shortens step-and-settle times.
PI’s New A-323 Air Bearing Scanner, Built in the USA for High-Throughput Wafer Metrology. Image Credit: PI (Physik Instrumente) LP
In its basic configuration, the A-323 provides 500 × 500 mm of XY travel at speeds up to 2 m/s and 2 g acceleration. Specified accuracy is 0.1 µm, with pitch and yaw performance of 10 µrad and 2 µrad, respectively.
Lower Center of Gravity, Better Dynamics
The A-323 uses a split-beam cross-axis design that places the payload lower and closer to the motor force plane. This reduces pitching and rocking during acceleration and shrinks the Abbe offset between the payload and the encoder measurement plane, limiting positioning errors caused by angular motion. A gantry configuration improves yaw control across the working area.
Drive and encoder points sit farther apart than on the A-322 Ultra, which gives more leverage over rotation about the vertical axis. This matters at the edge of a 300 mm wafer, where even a small yaw deviation produces a larger linear error than it does near the center.
Faster Settling Through Reaction-Force Management
Rapid moves can introduce vibration that delays measurement. The A-323 redirects motor reaction forces into the machine frame rather than the granite base. That reduces disturbances to the stage and to optics, cameras and sensors mounted on the granite bridge. The result is a more stable relationship between workpiece and measurement equipment during acceleration, settling and the transition to constant-velocity scanning.
Configurable for Real-World Systems
A central pocket holds application-specific motion modules, including PI’s A-523 Z-tip/tilt stage, a compact 5 mm Z-stage, a rotary axis, or combined rotary/Z/tilt modules. Keeping these axes low preserves the platform’s dynamic advantages.
Newly developed air-bearing pucks provide a stiffer air film, and opposing bearings maintain the magnetic preload during aggressive moves. Integrated cable tracks, pneumatic routing and cooling provisions simplify installation of customer-provided equipment, and symmetrical cable loops help limit position-dependent disturbances.
Room to Scale
The A-323 has demonstrated acceleration up to 2 g. At that level, performance is limited mainly by motor peak force, sustained RMS force and thermal loading rather than by the stage structure. Liquid-cooled motors manage heat, and motor sizing and cooling can be matched to payload and duty cycle. The architecture can accommodate larger motors where greater sustained performance is required. Final performance depends on the integrated payload, selected motion modules, motor configuration and operating conditions.
Availability and More Information
To discuss scanning requirements, payload configuration, additional motion axes or system integration, contact PI’s engineering team. Watch the A-323 video in high-speed scanning motion.
Applications and Industries Served
Semiconductor test and manufacture, wafer stealth slicing, optical metrology, photonics alignment, material research, laser processing