MASS SPECTROGRAPH AND ION IMPLANTATION DEVICE EQUIPPED WITH IT

摘要

PROBLEM TO BE SOLVED: To accurately conduct ion beam mass spectrometry by suppressing the arrival of secondary ions generated in a mass separator and left the mass separator at an ion detector. SOLUTION: In this mass spectrometer 20a, a reflection electrode 46 equipped with an ion passing through hole 48 and having a positive voltage V3 applied from a DC power source 50 is provided between a mass separator 26 and an ion detector 32. The level of the positive voltage V3 is set to be smaller than a voltage V1 obtained by converting the kinetic energy of an incident ion beam 6 to a mass separator 26 into an acceleration voltage, and is set to be larger than a voltage V2 obtained by converting the kinetic energy of secondary ions 44 generated in the mass separator 26 into an accelerating voltage.