A typical acoustic noise plot in which the noise measurement inside a service area is compared with the measurement made in a cleanroom
A typical comparison of stray magnetic fields with a tool specification in a tabular form
Site surveys are performed to determine whether a proposed location is
environmentally suitable for a particular tool. Depending on the kind of equipment to be
installed, the types of measurements performed will vary. Typically for a scanning
electron microscope site survey measurements, vibration, acoustic noise, and low frequency
stray magnetic fields measurements are performed. For an optical inspection tool,
vibration and acoustic noise measurements are made. Lastly for a stepper, only vibration
measurements are performed.
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.
