Temperature control in EUV reticle inspection tool

摘要

An apparatus comprises an optics assembly and a plate. The optics assembly configured to focus light from an EUV source onto a reticle or sensor. The plate has an opening to allow the EUV light to pass through disposed between the optics assembly and the reticle or sensor. The plate is cooled to a temperature less than that of the reticle or sensor. The plate is engineered to balance out heat absorbed from the reticle or sensor with heat absorbed by the plate. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

主权项

1. An apparatus comprising:
an optics assembly configured to direct light from an EUV source onto a workpiece, wherein the optics assembly is maintained at a specific temperature; and a plate with an opening to allow the EUV light to pass through disposed between the optics assembly and the workpiece, wherein the plate is cooled to a temperature less than the specific temperature and wherein the plate is engineered to balance out heat radiated from the workpiece with heat absorbed by the plate when the EUV light impinges on the workpiece, wherein a portion of an area of the plate that has a view to the optics assembly and is less than a full area of the plate is engineered to have an emissivity that is different from other portions of the area of the plate.