Long Scan Stage for the Metrological Atomic Force Microscope

This paper presents the design and fabrication of a long scan stage for metrological atomic force microscope. On designing the system, we mainly consider a simple structure with low vibration and high accuracy. In stead of the traditional two level stages, we used a surface plate as the reference of the main stage. Therefore, it has low profile and simple structure. Surface plate was made of the ceramic glass with very low thermal expansion. The stage is positioned on the surface plate of 800 mm x 800 mm. It is guided horizontally by a cross structure with two precision bars perpendicularly linked and vertically by the surface plate. The sliding pads of PTFE are used at X- and Y-axes, and also used for vertically supporting the stage. The X-axis guide bar with a moving plate is glued on the surface plate. The Y-axis guide bar is attached to the X-axis moving plate and moved to the Y-direction. Finally the Y-axis guide bar guides the XY-stage plate, so the XY-stage plate can be moved to two directions. This global stage also has the two-axis flexure structure machined by the precision wire-cutting machine. By combining global stage and micro-stage, the fast and long movement and the fine positioning can be provided. A two-axis tilt stage for adjusting the pitch motions of the stage and a L-shaped mirror for laser interferometer is positioned on the tilt stage