Patent ID: 6984833
Filing Date: 2006-01-10
Classification: H01J

Abstract:
1. A method for controlling an ion implanter which performs ion implantation by irradiating wafers on a disc disposed in a vacuum processing chamber with an ion beam generated in an ion source through a mass analysis magnet apparatus and a mass analysis slit, the ion implanter having current measurement means measuring at least one beam current at the rear side of the disc in the vacuum processing chamber as a measured beam current while the disc is rotated, pressure measurement means measuring at least one vacuum pressure in the vicinity of a position at which the wafers are irradiated with the ion beam, and a vacuum pressure compensation mechanism having functions of sampling the measured beam currents and the vacuum pressures under a plurality of conditions in preliminary implantation, fitting the relationship between the sampled measured beam currents and vacuum pressures to a predetermined function, storing at least one function parameter obtained by calculation of at least one parameter of the function, correcting the measured beam current using the stored function parameter in actual implantation, and performing dosage control in accordance with the corrected beam current, the method comprising: performing secondary compensation for an actual beam loss based on the estimation from the pressure measured in the vicinity of the position at which the wafers are irradiated with the ion beam in a region downstream of the mass analysis slit, the actual beam loss being caused by a pressure increase of a beam line inside the mass analysis magnet apparatus in a beam deflection and travel zone from an inlet of the mass analysis magnet apparatus to the mass analysis slit.