Fabrication of an Integrated Silicon-Based Lens for Low-Energy Miniaturized Electron Columns

A new process for the microfabrication of a fully integrated electrostatic lens in silicon, in particular the design of a low-energy miniaturized electron column, is described. It is suitable for batch processing and reduces considerably the difficulties associated with lens assembly. The electrode-spacer-electrode stack comprises an epitaxial p-n-p doped layer structure in silicon, which serves as electrodes and spacers, respectively. Because this technique allows the dimensions of the lens to be reduced, and owing to a new technique to align the electrode bores, the aberration of the lens is expected to be lower than that of lenses fabricated with previously reported techniques.