Optical unit e.g. object lens for lithography, cleaning and repairing method for delamination of optical unit, involves immersing optical unit with area that is be treated in treatment liquid, where liquid is neutral or basic solution

摘要

The method involves immersing an optical unit with an area that is to be treated in a treatment liquid or wetting the optical unit using the liquid, and exposing the surface to the liquid for a pre-determined time period, where the liquid is a neutral or a basic solution. The treatment of the optical unit is performed in a room temperature. The unit is rinsed with water or cleaning agent after immersion of the unit. An independent claim is also included for a treatment liquid for cleaning and repairing an optical unit.