Apparatus and methods for ion implantation

Abstract

A system for implanting ions of a prearranged chemical species into a plurality of semiconductor wafers. A beam analyzing arrangement receives an ion beam and selective separates various ion species in the beam on the basis of mass to produce an analyzed beam exiting the analyzing arrangement. A wafer scanning arrangement scans a plurality of wafers through the accelerated ion beam. The analyzing arrangement has an ion dispersion plane associated therewith and the source arrangement has an associated ion emitting envelope including an area pf substantial extension in a plane parallel to the ion dispersion plane and produces an ion beam characterized by a beam envelope which retains an area of substantial extension in a plane paralled to ion dispersion plane throughout the region between the source and the analyzing arrangement and by ions entering the analyzing arrangement travelling substantially either toward or from a common apparent line object perpendicular to the ion dispersion plane. The wafer scanning arrangement comprises a scan wheel assembly for carrying a plurality of semiconductor wafers and having a central axis, and a drive arrangement for rotating the scan wheel assembly about the central axis to scan the wafers across the beam in one coordinate direction. A scan arrangement produces relative scanning movement between the scan wheel and the ion beam in another coordinate direction.