The PM220/225 Series detectors are used to measure two fixed wavelengths in the range of 185–830nm. When used with Verity’s system controllers, the PM220/225 Series provides robust endpoint detection in appropriate applications. This series is most commonly used in applications where the chemistry is simple enough that overlapping spectra allow the use of a 10nm bandpass filter — but where two signals are necessary to ensure endpoint, or where two wavelengths are useful for alternative process recipes.

The PM225 detector accommodates two light emission inputs through fiber optic cables. The PM220^TM detector includes a KF40 flange for direct mounting to the vacuum chamber. A quartz or sapphire window provides vacuum isolation, although the sapphire window provides better resistance to window etching than the quartz window.