Cleaning module for cleaning multi-layer mirror of extreme UV projection exposure system of semiconductor lithography plant, has heating element for heating hydrogen at temperature below dissociation temperature of hydrogen

摘要

The module has a supplying device for supplying molecular hydrogen (2), and a tungsten coil (3) for producing atomic hydrogen. A heating element (4) heats the atomic and molecular hydrogen at a temperature below dissociation temperature of the atomic and molecular hydrogen. The heating element comprises a larger surface than that of the coil and is switched independent of the coil, where the heating element and the coil are connected with same ground line. A control unit controls voltage at the heating element and the coil, where the heating element is made of tungsten.