Estimation of keV submicron ion beam width using a knife-edge method

Ishii, Yasuyuki; Isoya, Akira*; Kojima, Takuji; Arakawa, Kazuo

A beam width measurement system has been developed for keV submicron ion beams of 0.1 m or less in width assuming a round shape beam. The system enables to measure beam current change as a function of knife-edge position by cutting a beam focusing point (beam spot) with the sharp edge within a spatial resolution of 0.02 m. The width of 30 keV order submicron ion beam was estimated by fitting current change curves based on three different ion density models: uniform, flat-top and Gaussian. Among these models, the flat-top model provide the most reasonable beam width of 0.56 m interpreting contribution of halo around the beam spot to beam width estimation. The beam width measurement system with the high spatial resolution and the data analysis based on the flat-top ion density model should contribute to accelerate developments of submicron ion beam production technologies.