Methods and apparatus for ion beam angle measurement in two dimensions

Abstract

An angle measurement system for an ion beam includes a flag defining first and second features, wherein the second feature has a variable spacing from the first feature, a mechanism to translate the flag along a translation path so that the flag intercepts at least a portion of the ion beam, and a sensing device to detect the ion beam for different flag positions along the translation path and produce a sensor signal having a first signal component representative of the first feature and a second signal component representative of the second feature. The first and second signal components and corresponding positions of the flag are representative of an angle of the ion beam in a direction orthogonal to the translation path. The sensing device may be a two-dimensional array of beam current sensors. The system may provide measurements of horizontal and vertical beam angles while translating the flag in only one direction.

Dependencies are inferred from the claim text.