Patent ID: 7105839

Claim:
In an ion implantation apparatus including a source for the generation of charged particles as an ion beam, a scanner which deflects the ion beam through a varying angle to yield a scanned ribbon beam, and a plane surface for the implantation of charged particles in the scanned ion beam into a workpiece which is moved through the scanned beam, the improvement of a fine-control collimator/steerer for accurate collimation and alignment of scanned beams, said fine-control collimator/steerer being comprised of: first and second multideflector sequence arrangements symmetrically encompassing the width of the scanned ribbon beam, wherein each said multideflector sequence arrangement comprises (1) a linear support bar comprising ferromagnetic material and having a fixed length and girth, and (2) at least two coil deflectors wound independently and positioned adjacently at pre-chosen sites on said support bar, each of said coil deflectors being formed of electrically conductive wire and being wound to lie orthogonally to said support bar, and (3) at least a pair of steering coils wound independently and positioned individually at each end of said support bar; first on-demand controls for passing electrical energy of variable current independently and concurrently through each adjacently positioned coil deflector on each of said support bar of said first and second multideflector sequence arrangements, whereby a. each adjacently positioned coil deflector becomes energized, b. each energized coil deflector independently generates an adjustable local magnetic potential gradient of limited breadth and a magnetic field extending orthogonally between said linear support bars, c. a plurality of said magnetic potential gradients of limited breadth concurrently and collectively form a contiguous magnetic field orthogonally extending between said first and second multideflector sequence arrangements, and d. each adjustable local magnetic potential gradient within said contiguous magnetic field can be individually and concurrently altered at will to yield a pre-selected magnetic field gradient profile which extends over the linear length of said support bars; second on-demand controls for passing electrical energy of variable current independently and concurrently through each said steering coil positioned at the ends of each said support bar whereby said steering coils become energized and generate an orthogonally extending magnetic field of limited breadth and an adjustable local magnetic potential gradient at each end of said linear support bar; a spatial channel bounded by said mulfideflector sequence arrangements for applying a contiguous magnetic field and a pre-selected magnetic field gradient profile to a scanned ion beam traveling therethrough, wherein the parallelism for a scanned ion beam becomes finely controlled and more accurate.