Distributed Ion Source Acceleration Column
AssigneesFEI Company, Government of the United States of America as Represented by the Secretary of Commerce, The Nati, The Standard Co., Ltd.
InventorsJabez J. McClelland, Brenton J. Knuffman, Adam V. Steele, Jonathan H. Orloff
Life of this patent
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Abstract
An ion beam system uses a separate accelerating electrode, such as a resistive tube, to accelerate the ions while maintaining a low electric field at an extended, that is, distributed ion source, thereby improving resolution. A magneto-optical trap can be used as the ion source.
Claims26
An ion source for providing ions for a focused ion beam directed to a sample on a sample stage, comprising:
- a source region for containing supercold neutral atoms;
- a source electrode on one side of the source region;
- an extractor electrode on the opposite side of the source region form the source electrode, the extractor electrode having a hole, the source electrode and extractor electrode providing a source electric field having a source electric field strength across the source region;
- an energy source for ionizing at least some of the supercold neutral atoms to create ions, the ions being accelerated by the source electric field through the hole;
- and
- a resistive tube having different electrical potential along the tube for receiving ions from the hole in the extractor electrode and accelerating the ions.
An ion source for providing ions for a focused ion beam directed to a sample on a sample stage, comprising:
- a source region for containing supercold neutral atoms;
- a source electrode on one side of the source region;
- an extractor electrode on the opposite side of the source region form the source electrode, the extractor electrode having a hole, the source electrode and extractor electrode providing a source electric field having a source electric field strength across the source region;
- an energy source for ionizing at least some of the supercold neutral atoms to create ions, the ions being accelerated by the source electric field through the hole;
- at least one extension electrode providing an extension electric field extending from the electrode with the hole, the strength of the extension electric field just beyond the hole differing from the strength of the source electric field by lens than thirty percent, thereby reducing or eliminating focusing effects as ions leave the source region.
An ion source for providing ions for a focused ion beam directed to a sample on a sample stage, comprising:
- an source region for providing ions;
- one or more electrodes for providing an electrical potential at the extended source region;
- an extractor electrode having a hole, the extractor electrode providing an electric field for extracting ions from the source region;
- and
- an accelerating electrode having different electrical potentials at different points along the electrode tube for receiving ions from the hole in the extractor electrode and accelerating the ions.
Dependencies are inferred from the claim text.