| 摘要 |
An improved method and apparatus are provided for cleaning the specimen and interior specimen chamber of Electron Microscopes, and similar electron beam instruments. The apparatus consists of a UV source oxygen-radical generator placed on a specimen chamber port or inside the specimen chamber under vacuum. Air or other oxygen and nitrogen mixture is admitted to the generator at a pressure below 1 Torr. The UV source radiates UV wavelengths below 190 nm that are used to disassociate oxygen to create the oxygen radicals. The oxygen radicals then disperse by convective flow throughout the chamber to clean hydrocarbons from the surfaces of the chamber, stage and specimen by oxidation to volatile oxide gases. The oxide gases are then removed by the convective flow to the vacuum pump. In particular it is a novel method and apparatus for cleaning the specimen chamber, specimen stage, and specimen inside the vacuum system of these instruments with oxygen radicals produced from air or other oxygen containing gas by photo-dissociation by passing said gas by a UV source with wavelengths that can produce oxygen radicals. The oxygen radicals are used to oxidize the hydrocarbons and convert them to easily pumped gases. The method and apparatus can be added to the analytical instrument and other vacuum chambers with no change to its analytical purpose or design.
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