Nanoscale freestanding gratings for ultraviolet blocking filters

Ultraviolet (UV) blocking filters are needed for atomic flux imaging in env ironments where high levels of ultraviolet radiation are present. Freestand ing gratings are a promising candidate for UV filtering. They have a high a spect ratio (similar to 13), narrow (similar to 40 nm) slots, and effective ly block UV radiation. The grating fabrication process makes use of several etching, electroplating, and lithographic steps and includes an optional s tep to plug pinholes induced by particles during processing. Gratings were- successfully manufactured and tested. Measured UV transmissions of similar to 10(-5) and particle transmissions of similar to 10% are in agreement wit h theoretical predictions. (C) 1998 American Vacuum Society. [S0734-211X(98 )03806-2].