AirLift 115 vertical translation stage

Aerotech has introduced its AirLift 115 sub-micron resolution vertical translation stage, which it claims maintains an almost perfect straight line performance over a travel range up to 150mm at speeds to 50mm/s. Aimed at demanding application areas such as semiconductor testing, nanoscale metrology, optical inspection and laser micromachining, the stage features a fully preloaded vertical air bearing in combination with a servomotor driven precision-ground ballscrew in a compact design that includes an innovative drive mechanism without the need for a load counterbalance system.

Unlike conventional wedge-style designs for vertical translation, which offer limited Z-direction angular performance and a restricted travel range (typically of just a few millimetres), the AirLift 115 maintains an angular performance of better than +/- 1 arc-sec in pitch, yaw and roll for the 50mm travel version. The range also covers 100mm and 150mm travel versions where angular accuracy performance is still within +/- 2 arc-sec. Positioning resolution across the range is 50nm with repeatability within +/- 0.5µm. Overall calibrated positional accuracy for the 50mm travel version is within +/- 1.0µm and for the 150mm travel version, +/- 1.5µm.

The specifications allow positioning and micromanipulation of workpieces to be held to remarkably high levels of flatness for applications where an unobstructed view of the work plane is required - such as wafer inspection or laser processing. The long travel range, high bearing stiffness and high speed capability also combine for rapid workpiece loading well away from work area with the added bonus that the horizontal footprint is also relatively small in comparison to tradition vertical stage designs.