In situ beam angle measurement in a multi-wafer high current ion implanter

The average angle measured in this way is found to be consistent with that obtained by other techniques, including beam centroid offset and wafer channeling methods. Average angle of low energy beams, for which it is difficult to use other direct methods, is explored. A “pencil beam” system is shown to give average angle repeatability of 0.13° (1σ) or less, for two low energy beams under normal tuning variations, even though no effort was made to control the angle.