Multi-electron-beam deflector array

In single electron beam columns the alignment of the beam is obtained either by mechanical shifting the lenses or by x/y alignment deflectors. We are developing multi electron beam columns for electron microscopy and lithography. The problem in multi-beam systems is that mechanical alignment and simple x/y deflectors can only align the total array of beams in the x/y direction and not correct the position of individual beamlets. We present here a simple design, fabrication, electron-optical analysis and experimental results of a multi-beam x/y deflector array that can deflect each beamlet separately. The array is fabricated with micro-fabrication technology with in-plane deflection plates made of molybdenum. The electron optical properties of this in-plane deflector are simulated and compared to a traditional deflector. The experimental measurements are compared with the simulations and are in agreement. (C) 2014 Elsevier B.V. All rights reserved.