Source identification measurements

Relative displacement between target and lens and the corresponding structural modes of optics and target

Stage system showing the structural modes and the simultaneously measured ambient acoustic noise and vibration displacement

Occasionally measurements are made to identify a source of vibration, acoustic noise, and/or low frequency stray magnetic fields for a SEM or an optical inspection tool with an image problem. Tests for vibration, acoustic noise, and low frequency stray magnetic fields are performed to determine the nature of the problem.