Abstract: A method and apparatus for electron beam processing using an electron beam activated gas to etch or deposit material. The invention is particularly suitable for repairing defects in lithography masks. By using an electron beam in place of an ion beam, the many problems associated with ion beam mask repair, such as staining and riverbedding, are eliminated. Endpoint detection is not critical because the electron beam and gas will not etch the substrate. In one embodiment, xenon difluoride gas is activated by the electron beam to etch a tungsten, tantalum nitride, or molybdenum silicide film on a transmission or reflection mask. To prevent spontaneous etching by the etchant gas in processed sites at which the passivation layer was removed, processed sites can be re-passivated before processing additional sites.

Abstract: A method and apparatus for electron beam processing using an electron beam activated gas to etch or deposit material. The invention is particularly suitable for repairing defects in lithography masks. By using an electron beam in place of an ion beam, the many problems associated with ion beam mask repair, such as staining and riverbedding, are eliminated. Endpoint detection is not critical because the electron beam and gas will not etch the substrate. In one embodiment, xenon difluoride gas is activated by the electron beam to etch a tungsten, tantalum nitride, or molybdenum silicide film on a transmission or reflection mask. To prevent spontaneous etching by the etchant gas in processed sites at which the passivation layer was removed, processed sites can be re-passivated before processing additional sites.