| 摘要 |
PURPOSE:To enable an ion beam with a large output to be drawn by using a blade-like chip, and utilizing electronic impact carried out with a filament, which is placed almost parallel to the blade, as a method of heating said chip and an ion source material. CONSTITUTION:An ion source consists of a blade-like chip 2', an ion source reservoir 7 from which the bladed end of the chip 2' partially protrudes, a filament 1 which is used as an electron source and placed in linear form along and parallel to the blade, and an electron-accelerating power source 6; a space is allowed between the chip 2' and the reservoir 7. After an ion source material 3 is packed in the ion source reservoir 7, the filament 1 is heated. Next, the ion source material 3 is heated and molten by electrons discharged from the filament 1. As a result, the ion source material 3 in molten form is supplied to the pointed end of the chip 2'. After that, high voltage is applied to both a lead-out electrode and the pointed end of the chip 2' so as to draw an ion beam 5 by field emission. The thus discharged ion beam 5 is introduced into a mass separator system such as a sector magnetic field, where the ion beam 5 is separated into arbitrary ionic kinds by mass separation. A specific kind of ion obtained by mass separation is irradiated on a base plate on which the ion is intended to be implanted, and is implanted at an arbitrary concentration. |
