Method and apparatus for reducing cross contamination of species during ion implantation
AssigneeApplied Materials, Inc.
InventorAdrian Murrell
Life of this patent
Estimating the term…
Abstract
A wafer support for an ion implanter includes a wafer holder and a support arm for the holder in the implant chamber. A portion of the support arm adjacent the wafer holder is at least intermittently exposed to the ion beam during implantation, as a result of the relative scanning of the ion beam and the wafer holder. An arm shield mechanism has a plurality of shielding surfaces which can be selectively disposed to receive the ion beam to protect the exposed portion of the support arm. The shielding surfaces may form a sleeve arranged over the arm which may be rotatable above the arm to present selected surfaces to the ion beam. Cross contamination when successively implanting different species can be reduced by presenting different shield surfaces to the beam.
Claims13
Wafer support apparatus for an ion implanter having an implantation chamber for receiving an ion beam, comprising
- a wafer holder for holding a wafer in the implantation chamber during implantation,
- an arm carrying the wafer holder in the implantation chamber and having an arm portion adjacent the wafer holder which is at least intermittently exposed to the ion beam during implantation, and
- an arm shield mechanism on the arm and having a plurality of shielding surfaces which can be selectively disposed to shield said arm portion from said at least intermittent exposure to the ion beam.
A method for protecting an arm of a wafer support apparatus for an ion implanter, the implanter having an implantation chamber for receiving an ion beam, the arm carrying a wafer holder in the implantation chamber and having aan arm portion adjacent the wafer holder which is at least intermittently exposed to the ion beam during wafer implantation,
- the method comprising;
- disposing a first shielding surface of a shield mechanism on the arm to shield said exposed arm portion from said at least intermittent exposure to the ion beam for a pre-determined number of processes, and
- disposing a second shielding surface to protect the said exposed arm portion after a pre-determined number of wafer processes or if the ion species in the ion beam is changed.
A shield apparatus for mounting on an arm carrying a wafer holder in an implantation chamber of an ion implanter, said shield apparatus being arranged for protecting the arm from ions in an ion beam during a wafer ion implantation process, said apparatus comprising
- a plurality of shield portions, each being movable between a first and second position with respect to the arm, so that during an ion implantation process, ions in the ion beam are prevented from hitting the arm by a shield portion in the first position, and substantially no ions in the ion beam hit a shield portion in the second position.
Dependencies are inferred from the claim text.