Ion implanter and method for controlling the same

摘要

The present invention is applied to an ion implanter provided with a vacuum pressure compensation mechanism. The pressure compensation mechanism samples measured beam currents and vacuum pressures in the vicinity of wafers in preliminary implantation and stores function parameters in a memory unit which are obtained by calculating parameters of a predetermined function by fitting the relationship between the measured beam currents and the vacuum pressures. In actual implantation, the pressure compensation mechanism corrects the measured beam current using the function parameters stored as a function of the vacuum pressure, and based on the corrected beam current, the dosage control is performed. In the present invention, an actual beam loss is compensated for based on the estimation from a pressure in the vicinity of the wafers in a region downstream of a mass analysis slit.