| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem where an opening hole beings to be blocked, with increased service frequency, when the aspect ratio of the opening diameter of a throttle to the length thereof becomes 5 or larger, precluding the desired maximum beam current. SOLUTION: A throttle hole is formed into an inversely tapered shape, which becomes larger the further downstream side a beam is located, or in a stepwise shape which becomes as larger, the further downstream side of the beam it is. Technology for stabilizing ion emission from Ga liquid metal ion source(LMIS) and technology suited to an ion device having a great current and high beam current density are established therewith.
|
