LITHOGRAPHIC APPARATUS COMPRISING A CLEANING ARRANGEMENT, CLEANING ARRANGEMENT AND METHOD FOR CLEANING A SURFACE TO BE CLEANED

摘要

A cleaning arrangement is provided for use in an EUV lithographic apparatus, for example an EUV lithographic apparatus with a Sn source. The cleaning arrangement includes a gas source for a hydrogen containing gas and a hydrogen radical source. The hydrogen radical source is a source of (UV) radiation which induces photo dissociation of the hydrogen. Radicals may reduce Sn oxides (if present) and my form volatile hydrides of Sn deposition and/or carbon deposition. In this way the cleaning arrangement can be used to clean optical elements from Sn and/or C deposition. The EUV source may be used as hydrogen radical source. An optical filter is used to remove undesired EUV radiation and transmit desired UV radiation.