Patent ID: 7611975

Claim:
A method of implanting a substrate wafer having an implant surface with a predetermined diameter, the method comprising: a) generating an implant beam having a predetermined beam direction, b) holding said substrate wafer aligned in an implant plane, normal to said beam direction, c) said beam having orthogonal cross-sectional dimensions in said implant plane each of which is less than said predetermined wafer diameter, and d) mechanically scanning said substrate wafer in two dimensions in said implant plane to provide a desired uniform total implant dose over the implant surface of the substrate wafer, said mechanically scanning comprising a first mechanically driven reciprocating movement of the wafer along a first translational direction, and a second mechanically driven reciprocating movement of the wafer along a second translational direction different from said first translational direction, wherein said mechanical scanning is performed so as to deliver said total implant dose in first and second parts, said first part being delivered by performing said mechanical scanning with said substrate wafer held in a first constant orientation about a twist axis parallel to said predetermined beam direction, and said second part being delivered to complete said total implant dose by performing said mechanical scanning with the substrate wafer held in a second constant orientation at 180° to said first orientation about said twist axis.