An optical window deposition shield including a backing plate having a
through hole, and a honeycomb structure having a plurality of adjacent
cells configured to allow optical viewing through the honeycomb
structure. Each cell of the honeycomb structure has an aspect ratio of
length to diameter sufficient to impede a processing plasma from
traveling through the full length of the cell. A coupling device
configured to couple the honeycomb core structure to the backing plate
such that the honeycomb structure is aligned with at least a portion of
the through hole in the backing plate. The optical window deposition
shield shields the optical viewing window of a plasma processing
apparatus from contact with the plasma.