Patent ID: 6646276
Filing Date: 2003-11-11
Classification: H01J

Abstract:
An ion implantation apparatus comprising:an ion beam source for producing an ion beam; a rotatable substrate holder downstream of the ion beam source, the substrate holder having a plurality of circumferentially spaced substrate supports; a two-dimensional mechanical scanner to mechanically scan the substrate supports relative to the ion beam to perform slow scans in a first, slow scanning, direction and multiple fast scans for each said slow scan, in a second, fast scanning, direction, the scanner being operative to scan in said second, fast scanning, direction by rotation of said substrate holder; a beam stop, downstream of the substrate holder, for capturing ions in the ion beam missing the substrate holder, to generate a beam stop current therefrom, a current sampler to produce a plurality of samples of the beam stop current which is generated by the beam ions captured by the beam stop which have passed between adjacent pairs of the circumferentially spaced substrate supports, and a processor to receive said plurality of samples and compare said plurality of samples from the beam ions passing between successive said adjacent pairs of substrate supports to monitor the continuity of the ion beam during each rotation of the substrate holder.