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US 6,060,715 AGranted
Method and apparatus for ion beam scanning in an ion implanter
AssigneeApplied Materials, Inc.
InventorsJonathan Gerald England, Andrew Holmes
Life of this patent
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AssigneeApplied Materials, Inc.
InventorsJonathan Gerald England, Andrew Holmes
Estimating the term…
An ion implanter for implanting ions in a target substrate is arranged to scan the ion beam at the point of extraction of the beam from the ion source. The ion beam extraction assembly includes a tectrode construction in which an extraction electrode adjacent the ion source aperture is split into two halves. A differential voltage is applied across the two halves of the extraction electrode to deflect the ion beam being extracted from the ion source electrostatically. The plane of deflection is arranged to coincide with the plane if dispersion of the ions in a mass analyser magnet downstream of the extraction point and the deflected beam of ions of desired mass/charge ratio is still brought to focus at a common mass selection slit at the exit of the analyser magnet.
An ion implanter for implanting ions in a target substrate, comprising an ion source, an ion beam extraction assembly for extracting ions from the ion source and forming a beam of the extracted ions, a target substrate holder, and an ion mass selector between said extraction assembly and said substrate holder for selecting ions of a desired mass in said beam of extracted ions for implanting in said target substrate, said extraction assembly being arranged for controllably deflecting said beam of extracted ions over a predetermined maximum deflection angle, at least in a deflection plane, said ion mass selector being operative to select ions of said desired mass in the deflected beam over said maximum deflection angle, whereby a beam of mass selected ions can be scanned over said target substrate by controlling the deflection angle at the extraction assembly.
An electrode assembly for extracting ions from an arc chamber and forming a steerable beam of the extracted ions, the electrode assembly comprising a first apertured electrode adapted to form a front face of the arc chamber and forming an exit aperture through which ions can be extracted from the arc chamber, a second apertured electrode adjacent the first electrode and having electrically separate components forming opposite sides of the aperture of said second electrode to form an electrostatic deflection lens, a third apertured electrode adjacent said second electrode and a fourth apertured electrode adjacent said third electrode, said first, second, third and fourth electrodes being electrically insulated from one another.
A method of scanning an ion beam across a target substrate in an ion implanter comprising an ion source, an ion beam extraction assembly for extracting ions from the ion source and forming a beam of the extracted ions at a predetermined energy, a holder for the target substrate, and an ion mass selector between said extraction assembly and said substrate holder for selecting ions of a desired mass in said beam of extracted ions for implanting in said target substrate, the method comprising electrostatically deflecting the ions in the extraction assembly transversely of the beam direction at a position where the ions experience an accelerating or decelerating field in the beam direction, thereby angularly steering the direction of said beam, passing the steered beam through the ion mass selector to provide a steered beam of mass selected ions, and changing the angle of said beam of extracted ions to scan the beam of mass selected ions across the target substrate.
Dependencies are inferred from the claim text.