| 摘要 |
PURPOSE:To realize fine processing of a material and etching without its surface being contaminated and damaged, by composing a sample holder of a conductive material and providing a switching means to electrically earth or open the sample holder. CONSTITUTION:A holder 13 for holding a sample is composed of a conductive material such as Al. A switching means 12 is provided to electrically earth or open the holder 13. First, etching is performed in a state where the holder 13 is earthed, that is, by the same method as conventional one. Second, after etching is performed to aimed depth, the holder 13 is switched to be in its opening state from in its earthed state. At this time an effective ion acceleration voltage is decreased and also an etching rate is reduced correspondingly. An etching effect is improved by neutral radicals, and hence contamination and damage in the vicinity of the surface, caused by said etching, are removed.
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