Six Degree of Freedom Vibration Isolation Platform for In-Line Nano-Metrology

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.