Patent ID: 7199383
Filing Date: 2007-04-03
Classification: H01J

Abstract:
1. A method for reducing particles during ion implantation, comprising: loading a semiconductor wafer into an ion implanter, said ion implanter comprising an ion source, a mass analyzer, a disk assembly for holding said semiconductor wafer; blocking an ion beam selected from said mass analyzer by interposing a movable Faraday flag between said mass analyzer and said semiconductor wafer to a closed position, wherein said Faraday flag comprises a beam plate having thereon a beam striking zone comprising a plurality of recessed trenches on which said ion beam scans to and fro; wherein said ion beam impinges upon said plurality of recessed trenches and wherein sputtered particles resulting from beam strike on said beam plate are trapped at bottoms of said recessed trenches and thus preventing said sputtered particles from falling out of said Faraday flag; measuring a beam current of said ion beam impinging on said beam striking zone of said beam plate; and removing said Faraday flag such that said ion beam impinges on said semiconductor wafer.