A six degree of freedom, magnetically levitated metrology platform is proposed and implemented to enable nano-scale measurements directly in a production environment by providing vibration isolation. The metrology platform maintains a constant distance between sample and nano-metrology tool, forming a nano-scale laboratory environment directly in the production line. This paper presents the design of the proposed metrology platform. Tracking of the sample is achieved by using six position sensors, a six degree of freedom actuator and feedback control. Experimental results demonstrate positioning of the platform in six degrees of freedom at a bandwidth of 35 Hz in the translational directions and at a bandwidth of more than 15 Hz in the rotational directions, respectively. This results in a tracking error that is smaller than 50 nm rms. This paper denotes the first successful attempt for six degree of freedom vibration isolation to enable in-line nano-metrology.@en

Mechanical vibrations occuring in a production environment cause a relative motion between the sample and inspection tool that distorts measurements at the nanometer level. To overcome this problem, this paper proposes a metrology platform that maintains a constant relative distance to the sample by means of an H& inf;-feedback controller. Experiments in one degree of freedom show that the metrology platform can reduce vibrations as they occur in a production environment by one order of magnitude. Therefore, it enables in-line surface metrology at the nanometer level.@en