Dose control method
AssigneeEaton Corporation
InventorMarvin Farley
Life of this patent
Estimating the term…
Abstract
A method and apparatus for measuring and compensating for neutral ions in an ion beam in the dose control system of an ion implanter. The gas pressure in the implantation volume (15) is measured, and the pressure signal is converted to an effective beam current signal in accordance with a known relationship among the gas pressure, the apparent beam current as measured by a Faraday cage and the neutral beam. The resulting effective beam current signal is inputted to the dose control system.
Claims4
A method for controlling the dose of ions implanted into a workpiece by an ion implanter comprising the steps of measuring the ionized beam current at the workpiece, determining the current of the neutral atoms present in the beam striking the workpiece, adding the ionized beam current and the neutral beam current to obtain an effective beam current, and varying the dose of implantation as a function of the effective beam current.
Dependencies are inferred from the claim text.