| 主权项 |
1. A method of cleaning an element in an extreme ultraviolet (EUV) light source, the method comprising:
arranging a conduit relative to the element, the element being inside of a vacuum chamber of the EUV light source and in the path of EUV light emitted from a plasma and debris created by converting a target material to the plasma that emits the EUV light, the conduit comprising a sidewall that comprises a curved portion and a linear portion, the conduit being arranged with the linear portion passing through a wall of the vacuum chamber and the curved portion inside the vacuum chamber; receiving, at a first opening defined by a first end of the conduit, a moving gas and free radicals, the moving gas configured to carry the free radicals in the conduit, and the free radicals being configured to combine with the debris that is created by converting the target material to plasma that emits EUV light, the conduit comprising a metallic material, an inner surface of the conduit being coated with a material having a recombination coefficient of 5×10−3 or less, and the conduit defining a plurality of other openings, the other openings passing through the curved portion of the sidewall and positioned to release the free radicals toward an element that accumulates the debris on a surface; directing the moving gas to carry the free radicals in the conduit toward the plurality of other openings, the moving gas having a velocity and generating a back pressure in the conduit, the back pressure and the velocity being in different directions; reducing an amount of time that the free radicals spend in the conduit by increasing the velocity of the moving gas, the increased velocity of the moving gas changing the back pressure in the conduit; and passing the free radicals through at least one of the plurality of other openings and to the surface of the element to remove the debris from the surface of the element without removing the element from the EUV light source. |
