Patent ID: 6555831
Filing Date: 2003-04-29
Classification: H01J

Abstract:
An ion implanting apparatus comprisingan ion source having a plurality of filaments; one or more of filament sources for independently passing filament current to the respective filaments of the ion source; a plurality of beam current measuring instruments for measuring beam current of ion beam brought out from the ion source at a plurality of positions in planes crossing with the ion beam, the number of said beam current measuring instruments being more than the number of the filaments; and a control apparatus which controls filament current passing to the respective filaments from the filament sources in accordance with beam current measured by the beam current measuring instruments, and performs a current value control routine and a uniformity control routine of the beam current at least once respectively; wherein said current value control routine calculates the average values of all beam current measured by the plurality of beam current measuring instruments, and increases and decreases the filament current passing to said respective filaments by almost the same amount one another such that the average value comes near to the set value, and said uniformity control routine groups the plurality of beam current measuring instruments into the number of the filaments, seeks for a maximum value and a minimum value from all measured values by all beam current measuring instruments so as to respectively decide the groups to which the maximum value and the minimum value belong, decreases the filament current passing to the filament corresponding to the group to which the maximum value belongs and increases the filament current passing to the filament corresponding to the group to which the minimum value belongs.