Aerotech has developed the PlanarHDX, a planar air-bearing platform for semiconductor manufacturing and advanced test and inspection. The PlanarHDX was designed using an FEA-optimized silicon carbide structure and optimized air-bearing compensation techniques to provide the highest possible dynamic performance while maintaining unparalleled geometric characteristics and positioning accuracy.

PlanarHDX structural elements were designed using an advanced silicon carbide ceramic with a specific stiffness (elastic modulus/density) five times higher than aluminum and a coefficient of thermal expansion approximately five times lower. The resulting material and FEA-optimized structure enable 1.5 m/s scan speeds and 5 g peak acceleration with a payload of up to 20 kg for extremely high throughput processing – without sacrificing dynamic tracking, geometric performance, or thermal stability.

Other design enhancements include a new air-bearing compensation strategy that increases stiffness and load capacity for demanding high-dynamic applications. Using proven air-on-air preloading in critical bearing elements improves turnaround and settling times over vacuum-preloaded designs. A proprietary reaction-mass design dramatically reduces stage-induced forces in the step-axis that are transferred to the isolation system or customer’s structure (optics, sensors, etc.). By minimizing these dynamic forces, move-and-settle time is reduced and process throughput is increased.

The PlanarHDX is available with passive or active isolation systems. Additional axes such as Z-tip-tilt or Z-theta designs as well as custom wafer load/unload mechanisms and wafer chucks are available. Machine weldments, complex granite base structures, or enclosures can also be provided. Feedback options include low-expansion glass scale encoders or interferometer.

Advanced controls

Many advanced control features such as Directional Gain Scheduling, Iterative Learning Control, and Harmonic Cancellation are available to easily, quickly, and efficiently optimize your installation. Aerotech’s ETM (Enhanced Throughput Module) option helps improve the positioning performance of high-dynamic motion systems by directly measuring and compensating for the unwanted motion of the machine base.