Invention Grant
- Patent Title: Unbalanced ion source
- Patent Title (中): 不平衡离子源
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Application No.: US12079978Application Date: 2008-03-31
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Publication No.: US08072149B2Publication Date: 2011-12-06
- Inventor: Jeong-Ha Cho , Bon-Woong Koo , Byung-Yeal Yoon , Yong-Tae Kim , Jeong-Ho Yoon
- Applicant: Jeong-Ha Cho , Bon-Woong Koo , Byung-Yeal Yoon , Yong-Tae Kim , Jeong-Ho Yoon
- Applicant Address: US MA Gloucester
- Assignee: Varian Semiconductor Equipment Associates, Inc.
- Current Assignee: Varian Semiconductor Equipment Associates, Inc.
- Current Assignee Address: US MA Gloucester
- Main IPC: H01J7/24
- IPC: H01J7/24

Abstract:
A dual unbalanced indirectly heated cathode (IHC) ion chamber is disclosed. The cathodes have different surface areas, thereby affecting the amount of heat radiated by each. In the preferred embodiment, one cathode is of the size and dimension typically used for IHC ionization, as traditionally used for hot mode operation. The second cathode, preferably located on the opposite wall of the chamber, is of a smaller size. This smaller cathode is still indirectly heated by a filament, but due to its smaller size, radiates less heat into the source chamber, allowing the ion source to operate in cold mode, thereby preserving the molecular structure of the target molecules. In both modes, the unused cathode is preferably biased so as to be at the same potential as the IHC, thus allowing it to act as a repeller.
Public/Granted literature
- US20090243490A1 Unbalanced ion source Public/Granted day:2009-10-01
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